Merge remote-tracking branch 'origin/next' into kvm-ppc-next
Conflicts:
mm/Kconfig
CMA DMA split and ZSWAP introduction were conflicting, fix up manually.
diff --git a/mm/Kconfig b/mm/Kconfig
index 81bcb4b..6cdd270 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -501,3 +501,45 @@
messages for every CMA call as well as various messages while
processing calls such as dma_alloc_from_contiguous().
This option does not affect warning and error messages.
+
+config ZBUD
+ tristate
+ default n
+ help
+ A special purpose allocator for storing compressed pages.
+ It is designed to store up to two compressed pages per physical
+ page. While this design limits storage density, it has simple and
+ deterministic reclaim properties that make it preferable to a higher
+ density approach when reclaim will be used.
+
+config ZSWAP
+ bool "Compressed cache for swap pages (EXPERIMENTAL)"
+ depends on FRONTSWAP && CRYPTO=y
+ select CRYPTO_LZO
+ select ZBUD
+ default n
+ help
+ A lightweight compressed cache for swap pages. It takes
+ pages that are in the process of being swapped out and attempts to
+ compress them into a dynamically allocated RAM-based memory pool.
+ This can result in a significant I/O reduction on swap device and,
+ in the case where decompressing from RAM is faster that swap device
+ reads, can also improve workload performance.
+
+ This is marked experimental because it is a new feature (as of
+ v3.11) that interacts heavily with memory reclaim. While these
+ interactions don't cause any known issues on simple memory setups,
+ they have not be fully explored on the large set of potential
+ configurations and workloads that exist.
+
+config MEM_SOFT_DIRTY
+ bool "Track memory changes"
+ depends on CHECKPOINT_RESTORE && HAVE_ARCH_SOFT_DIRTY
+ select PROC_PAGE_MONITOR
+ help
+ This option enables memory changes tracking by introducing a
+ soft-dirty bit on pte-s. This bit it set when someone writes
+ into a page just as regular dirty bit, but unlike the latter
+ it can be cleared by hands.
+
+ See Documentation/vm/soft-dirty.txt for more details.
diff --git a/mm/Makefile b/mm/Makefile
index 72c5acb..f008033 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -32,6 +32,7 @@
obj-$(CONFIG_BOUNCE) += bounce.o
obj-$(CONFIG_SWAP) += page_io.o swap_state.o swapfile.o
obj-$(CONFIG_FRONTSWAP) += frontswap.o
+obj-$(CONFIG_ZSWAP) += zswap.o
obj-$(CONFIG_HAS_DMA) += dmapool.o
obj-$(CONFIG_HUGETLBFS) += hugetlb.o
obj-$(CONFIG_NUMA) += mempolicy.o
@@ -58,3 +59,4 @@
obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak-test.o
obj-$(CONFIG_CLEANCACHE) += cleancache.o
obj-$(CONFIG_MEMORY_ISOLATION) += page_isolation.o
+obj-$(CONFIG_ZBUD) += zbud.o
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 5025174..d014ee5 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -515,7 +515,6 @@
int bdi_setup_and_register(struct backing_dev_info *bdi, char *name,
unsigned int cap)
{
- char tmp[32];
int err;
bdi->name = name;
@@ -524,8 +523,8 @@
if (err)
return err;
- sprintf(tmp, "%.28s%s", name, "-%d");
- err = bdi_register(bdi, NULL, tmp, atomic_long_inc_return(&bdi_seq));
+ err = bdi_register(bdi, NULL, "%.28s-%ld", name,
+ atomic_long_inc_return(&bdi_seq));
if (err) {
bdi_destroy(bdi);
return err;
diff --git a/mm/bootmem.c b/mm/bootmem.c
index 2b0bcb0..6ab7744 100644
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -241,33 +241,26 @@
return count;
}
-static void reset_node_lowmem_managed_pages(pg_data_t *pgdat)
+static int reset_managed_pages_done __initdata;
+
+static inline void __init reset_node_managed_pages(pg_data_t *pgdat)
{
struct zone *z;
- /*
- * In free_area_init_core(), highmem zone's managed_pages is set to
- * present_pages, and bootmem allocator doesn't allocate from highmem
- * zones. So there's no need to recalculate managed_pages because all
- * highmem pages will be managed by the buddy system. Here highmem
- * zone also includes highmem movable zone.
- */
+ if (reset_managed_pages_done)
+ return;
+
for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
- if (!is_highmem(z))
- z->managed_pages = 0;
+ z->managed_pages = 0;
}
-/**
- * free_all_bootmem_node - release a node's free pages to the buddy allocator
- * @pgdat: node to be released
- *
- * Returns the number of pages actually released.
- */
-unsigned long __init free_all_bootmem_node(pg_data_t *pgdat)
+void __init reset_all_zones_managed_pages(void)
{
- register_page_bootmem_info_node(pgdat);
- reset_node_lowmem_managed_pages(pgdat);
- return free_all_bootmem_core(pgdat->bdata);
+ struct pglist_data *pgdat;
+
+ for_each_online_pgdat(pgdat)
+ reset_node_managed_pages(pgdat);
+ reset_managed_pages_done = 1;
}
/**
@@ -279,14 +272,14 @@
{
unsigned long total_pages = 0;
bootmem_data_t *bdata;
- struct pglist_data *pgdat;
- for_each_online_pgdat(pgdat)
- reset_node_lowmem_managed_pages(pgdat);
+ reset_all_zones_managed_pages();
list_for_each_entry(bdata, &bdata_list, list)
total_pages += free_all_bootmem_core(bdata);
+ totalram_pages += total_pages;
+
return total_pages;
}
diff --git a/mm/filemap.c b/mm/filemap.c
index 7905fe7..4b51ac1 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1539,12 +1539,12 @@
struct address_space *mapping = file->f_mapping;
/* If we don't want any read-ahead, don't bother */
- if (VM_RandomReadHint(vma))
+ if (vma->vm_flags & VM_RAND_READ)
return;
if (!ra->ra_pages)
return;
- if (VM_SequentialReadHint(vma)) {
+ if (vma->vm_flags & VM_SEQ_READ) {
page_cache_sync_readahead(mapping, ra, file, offset,
ra->ra_pages);
return;
@@ -1584,7 +1584,7 @@
struct address_space *mapping = file->f_mapping;
/* If we don't want any read-ahead, don't bother */
- if (VM_RandomReadHint(vma))
+ if (vma->vm_flags & VM_RAND_READ)
return;
if (ra->mmap_miss > 0)
ra->mmap_miss--;
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 362c329..243e710 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -729,8 +729,8 @@
pmd_t entry;
entry = mk_huge_pmd(page, vma);
page_add_new_anon_rmap(page, vma, haddr);
+ pgtable_trans_huge_deposit(mm, pmd, pgtable);
set_pmd_at(mm, haddr, pmd, entry);
- pgtable_trans_huge_deposit(mm, pgtable);
add_mm_counter(mm, MM_ANONPAGES, HPAGE_PMD_NR);
mm->nr_ptes++;
spin_unlock(&mm->page_table_lock);
@@ -771,8 +771,8 @@
entry = mk_pmd(zero_page, vma->vm_page_prot);
entry = pmd_wrprotect(entry);
entry = pmd_mkhuge(entry);
+ pgtable_trans_huge_deposit(mm, pmd, pgtable);
set_pmd_at(mm, haddr, pmd, entry);
- pgtable_trans_huge_deposit(mm, pgtable);
mm->nr_ptes++;
return true;
}
@@ -916,8 +916,8 @@
pmdp_set_wrprotect(src_mm, addr, src_pmd);
pmd = pmd_mkold(pmd_wrprotect(pmd));
+ pgtable_trans_huge_deposit(dst_mm, dst_pmd, pgtable);
set_pmd_at(dst_mm, addr, dst_pmd, pmd);
- pgtable_trans_huge_deposit(dst_mm, pgtable);
dst_mm->nr_ptes++;
ret = 0;
@@ -987,7 +987,7 @@
pmdp_clear_flush(vma, haddr, pmd);
/* leave pmd empty until pte is filled */
- pgtable = pgtable_trans_huge_withdraw(mm);
+ pgtable = pgtable_trans_huge_withdraw(mm, pmd);
pmd_populate(mm, &_pmd, pgtable);
for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
@@ -1085,7 +1085,7 @@
pmdp_clear_flush(vma, haddr, pmd);
/* leave pmd empty until pte is filled */
- pgtable = pgtable_trans_huge_withdraw(mm);
+ pgtable = pgtable_trans_huge_withdraw(mm, pmd);
pmd_populate(mm, &_pmd, pgtable);
for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
@@ -1265,7 +1265,9 @@
* young bit, instead of the current set_pmd_at.
*/
_pmd = pmd_mkyoung(pmd_mkdirty(*pmd));
- set_pmd_at(mm, addr & HPAGE_PMD_MASK, pmd, _pmd);
+ if (pmdp_set_access_flags(vma, addr & HPAGE_PMD_MASK,
+ pmd, _pmd, 1))
+ update_mmu_cache_pmd(vma, addr, pmd);
}
if ((flags & FOLL_MLOCK) && (vma->vm_flags & VM_LOCKED)) {
if (page->mapping && trylock_page(page)) {
@@ -1358,9 +1360,15 @@
struct page *page;
pgtable_t pgtable;
pmd_t orig_pmd;
- pgtable = pgtable_trans_huge_withdraw(tlb->mm);
+ /*
+ * For architectures like ppc64 we look at deposited pgtable
+ * when calling pmdp_get_and_clear. So do the
+ * pgtable_trans_huge_withdraw after finishing pmdp related
+ * operations.
+ */
orig_pmd = pmdp_get_and_clear(tlb->mm, addr, pmd);
tlb_remove_pmd_tlb_entry(tlb, pmd, addr);
+ pgtable = pgtable_trans_huge_withdraw(tlb->mm, pmd);
if (is_huge_zero_pmd(orig_pmd)) {
tlb->mm->nr_ptes--;
spin_unlock(&tlb->mm->page_table_lock);
@@ -1429,7 +1437,7 @@
if (ret == 1) {
pmd = pmdp_get_and_clear(mm, old_addr, old_pmd);
VM_BUG_ON(!pmd_none(*new_pmd));
- set_pmd_at(mm, new_addr, new_pmd, pmd);
+ set_pmd_at(mm, new_addr, new_pmd, pmd_mksoft_dirty(pmd));
spin_unlock(&mm->page_table_lock);
}
out:
@@ -1691,7 +1699,7 @@
pmd = page_check_address_pmd(page, mm, address,
PAGE_CHECK_ADDRESS_PMD_SPLITTING_FLAG);
if (pmd) {
- pgtable = pgtable_trans_huge_withdraw(mm);
+ pgtable = pgtable_trans_huge_withdraw(mm, pmd);
pmd_populate(mm, &_pmd, pgtable);
haddr = address;
@@ -2359,9 +2367,9 @@
spin_lock(&mm->page_table_lock);
BUG_ON(!pmd_none(*pmd));
page_add_new_anon_rmap(new_page, vma, address);
+ pgtable_trans_huge_deposit(mm, pmd, pgtable);
set_pmd_at(mm, address, pmd, _pmd);
update_mmu_cache_pmd(vma, address, pmd);
- pgtable_trans_huge_deposit(mm, pgtable);
spin_unlock(&mm->page_table_lock);
*hpage = NULL;
@@ -2667,7 +2675,7 @@
pmdp_clear_flush(vma, haddr, pmd);
/* leave pmd empty until pte is filled */
- pgtable = pgtable_trans_huge_withdraw(mm);
+ pgtable = pgtable_trans_huge_withdraw(mm, pmd);
pmd_populate(mm, &_pmd, pgtable);
for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index aed085a..83aff0a 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -319,7 +319,7 @@
hstate = hstate_vma(vma);
- return 1UL << (hstate->order + PAGE_SHIFT);
+ return 1UL << huge_page_shift(hstate);
}
EXPORT_SYMBOL_GPL(vma_kernel_pagesize);
@@ -1263,7 +1263,7 @@
* side-effects, like CommitLimit going negative.
*/
if (h->order > (MAX_ORDER - 1))
- totalram_pages += 1 << h->order;
+ adjust_managed_page_count(page, 1 << h->order);
}
}
diff --git a/mm/internal.h b/mm/internal.h
index 8562de0..4390ac6 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -32,11 +32,6 @@
set_page_count(page, 1);
}
-static inline void __put_page(struct page *page)
-{
- atomic_dec(&page->_count);
-}
-
static inline void __get_page_tail_foll(struct page *page,
bool get_page_head)
{
diff --git a/mm/memblock.c b/mm/memblock.c
index c5fad93..a847bfe6 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -566,7 +566,7 @@
/**
* __next_free_mem_range - next function for for_each_free_mem_range()
* @idx: pointer to u64 loop variable
- * @nid: nid: node selector, %MAX_NUMNODES for all nodes
+ * @nid: node selector, %MAX_NUMNODES for all nodes
* @out_start: ptr to phys_addr_t for start address of the range, can be %NULL
* @out_end: ptr to phys_addr_t for end address of the range, can be %NULL
* @out_nid: ptr to int for nid of the range, can be %NULL
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 1947218..d12ca6f 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -187,10 +187,6 @@
struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
};
-struct mem_cgroup_lru_info {
- struct mem_cgroup_per_node *nodeinfo[0];
-};
-
/*
* Cgroups above their limits are maintained in a RB-Tree, independent of
* their hierarchy representation
@@ -267,28 +263,10 @@
/* vmpressure notifications */
struct vmpressure vmpressure;
- union {
- /*
- * the counter to account for mem+swap usage.
- */
- struct res_counter memsw;
-
- /*
- * rcu_freeing is used only when freeing struct mem_cgroup,
- * so put it into a union to avoid wasting more memory.
- * It must be disjoint from the css field. It could be
- * in a union with the res field, but res plays a much
- * larger part in mem_cgroup life than memsw, and might
- * be of interest, even at time of free, when debugging.
- * So share rcu_head with the less interesting memsw.
- */
- struct rcu_head rcu_freeing;
- /*
- * We also need some space for a worker in deferred freeing.
- * By the time we call it, rcu_freeing is no longer in use.
- */
- struct work_struct work_freeing;
- };
+ /*
+ * the counter to account for mem+swap usage.
+ */
+ struct res_counter memsw;
/*
* the counter to account for kernel memory usage.
@@ -303,8 +281,6 @@
bool oom_lock;
atomic_t under_oom;
- atomic_t refcnt;
-
int swappiness;
/* OOM-Killer disable */
int oom_kill_disable;
@@ -366,14 +342,8 @@
atomic_t numainfo_updating;
#endif
- /*
- * Per cgroup active and inactive list, similar to the
- * per zone LRU lists.
- *
- * WARNING: This has to be the last element of the struct. Don't
- * add new fields after this point.
- */
- struct mem_cgroup_lru_info info;
+ struct mem_cgroup_per_node *nodeinfo[0];
+ /* WARNING: nodeinfo must be the last member here */
};
static size_t memcg_size(void)
@@ -416,6 +386,11 @@
static void memcg_kmem_mark_dead(struct mem_cgroup *memcg)
{
+ /*
+ * Our caller must use css_get() first, because memcg_uncharge_kmem()
+ * will call css_put() if it sees the memcg is dead.
+ */
+ smp_wmb();
if (test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags))
set_bit(KMEM_ACCOUNTED_DEAD, &memcg->kmem_account_flags);
}
@@ -508,9 +483,6 @@
*/
static DEFINE_MUTEX(memcg_create_mutex);
-static void mem_cgroup_get(struct mem_cgroup *memcg);
-static void mem_cgroup_put(struct mem_cgroup *memcg);
-
static inline
struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *s)
{
@@ -561,15 +533,15 @@
*/
if (sk->sk_cgrp) {
BUG_ON(mem_cgroup_is_root(sk->sk_cgrp->memcg));
- mem_cgroup_get(sk->sk_cgrp->memcg);
+ css_get(&sk->sk_cgrp->memcg->css);
return;
}
rcu_read_lock();
memcg = mem_cgroup_from_task(current);
cg_proto = sk->sk_prot->proto_cgroup(memcg);
- if (!mem_cgroup_is_root(memcg) && memcg_proto_active(cg_proto)) {
- mem_cgroup_get(memcg);
+ if (!mem_cgroup_is_root(memcg) &&
+ memcg_proto_active(cg_proto) && css_tryget(&memcg->css)) {
sk->sk_cgrp = cg_proto;
}
rcu_read_unlock();
@@ -583,7 +555,7 @@
struct mem_cgroup *memcg;
WARN_ON(!sk->sk_cgrp->memcg);
memcg = sk->sk_cgrp->memcg;
- mem_cgroup_put(memcg);
+ css_put(&sk->sk_cgrp->memcg->css);
}
}
@@ -683,7 +655,7 @@
mem_cgroup_zoneinfo(struct mem_cgroup *memcg, int nid, int zid)
{
VM_BUG_ON((unsigned)nid >= nr_node_ids);
- return &memcg->info.nodeinfo[nid]->zoneinfo[zid];
+ return &memcg->nodeinfo[nid]->zoneinfo[zid];
}
struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg)
@@ -1148,6 +1120,58 @@
return NULL;
}
+static void mem_cgroup_iter_invalidate(struct mem_cgroup *root)
+{
+ /*
+ * When a group in the hierarchy below root is destroyed, the
+ * hierarchy iterator can no longer be trusted since it might
+ * have pointed to the destroyed group. Invalidate it.
+ */
+ atomic_inc(&root->dead_count);
+}
+
+static struct mem_cgroup *
+mem_cgroup_iter_load(struct mem_cgroup_reclaim_iter *iter,
+ struct mem_cgroup *root,
+ int *sequence)
+{
+ struct mem_cgroup *position = NULL;
+ /*
+ * A cgroup destruction happens in two stages: offlining and
+ * release. They are separated by a RCU grace period.
+ *
+ * If the iterator is valid, we may still race with an
+ * offlining. The RCU lock ensures the object won't be
+ * released, tryget will fail if we lost the race.
+ */
+ *sequence = atomic_read(&root->dead_count);
+ if (iter->last_dead_count == *sequence) {
+ smp_rmb();
+ position = iter->last_visited;
+ if (position && !css_tryget(&position->css))
+ position = NULL;
+ }
+ return position;
+}
+
+static void mem_cgroup_iter_update(struct mem_cgroup_reclaim_iter *iter,
+ struct mem_cgroup *last_visited,
+ struct mem_cgroup *new_position,
+ int sequence)
+{
+ if (last_visited)
+ css_put(&last_visited->css);
+ /*
+ * We store the sequence count from the time @last_visited was
+ * loaded successfully instead of rereading it here so that we
+ * don't lose destruction events in between. We could have
+ * raced with the destruction of @new_position after all.
+ */
+ iter->last_visited = new_position;
+ smp_wmb();
+ iter->last_dead_count = sequence;
+}
+
/**
* mem_cgroup_iter - iterate over memory cgroup hierarchy
* @root: hierarchy root
@@ -1171,7 +1195,6 @@
{
struct mem_cgroup *memcg = NULL;
struct mem_cgroup *last_visited = NULL;
- unsigned long uninitialized_var(dead_count);
if (mem_cgroup_disabled())
return NULL;
@@ -1191,6 +1214,7 @@
rcu_read_lock();
while (!memcg) {
struct mem_cgroup_reclaim_iter *uninitialized_var(iter);
+ int uninitialized_var(seq);
if (reclaim) {
int nid = zone_to_nid(reclaim->zone);
@@ -1204,37 +1228,13 @@
goto out_unlock;
}
- /*
- * If the dead_count mismatches, a destruction
- * has happened or is happening concurrently.
- * If the dead_count matches, a destruction
- * might still happen concurrently, but since
- * we checked under RCU, that destruction
- * won't free the object until we release the
- * RCU reader lock. Thus, the dead_count
- * check verifies the pointer is still valid,
- * css_tryget() verifies the cgroup pointed to
- * is alive.
- */
- dead_count = atomic_read(&root->dead_count);
- if (dead_count == iter->last_dead_count) {
- smp_rmb();
- last_visited = iter->last_visited;
- if (last_visited &&
- !css_tryget(&last_visited->css))
- last_visited = NULL;
- }
+ last_visited = mem_cgroup_iter_load(iter, root, &seq);
}
memcg = __mem_cgroup_iter_next(root, last_visited);
if (reclaim) {
- if (last_visited)
- css_put(&last_visited->css);
-
- iter->last_visited = memcg;
- smp_wmb();
- iter->last_dead_count = dead_count;
+ mem_cgroup_iter_update(iter, last_visited, memcg, seq);
if (!memcg)
iter->generation++;
@@ -1448,11 +1448,12 @@
return ret;
}
-int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *memcg)
+bool task_in_mem_cgroup(struct task_struct *task,
+ const struct mem_cgroup *memcg)
{
- int ret;
struct mem_cgroup *curr = NULL;
struct task_struct *p;
+ bool ret;
p = find_lock_task_mm(task);
if (p) {
@@ -1464,14 +1465,14 @@
* killer still needs to detect if they have already been oom
* killed to prevent needlessly killing additional tasks.
*/
- task_lock(task);
+ rcu_read_lock();
curr = mem_cgroup_from_task(task);
if (curr)
css_get(&curr->css);
- task_unlock(task);
+ rcu_read_unlock();
}
if (!curr)
- return 0;
+ return false;
/*
* We should check use_hierarchy of "memcg" not "curr". Because checking
* use_hierarchy of "curr" here make this function true if hierarchy is
@@ -3031,8 +3032,16 @@
if (res_counter_uncharge(&memcg->kmem, size))
return;
+ /*
+ * Releases a reference taken in kmem_cgroup_css_offline in case
+ * this last uncharge is racing with the offlining code or it is
+ * outliving the memcg existence.
+ *
+ * The memory barrier imposed by test&clear is paired with the
+ * explicit one in memcg_kmem_mark_dead().
+ */
if (memcg_kmem_test_and_clear_dead(memcg))
- mem_cgroup_put(memcg);
+ css_put(&memcg->css);
}
void memcg_cache_list_add(struct mem_cgroup *memcg, struct kmem_cache *cachep)
@@ -3223,7 +3232,7 @@
list_del(&s->memcg_params->list);
mutex_unlock(&memcg->slab_caches_mutex);
- mem_cgroup_put(memcg);
+ css_put(&memcg->css);
out:
kfree(s->memcg_params);
}
@@ -3383,16 +3392,18 @@
mutex_lock(&memcg_cache_mutex);
new_cachep = cachep->memcg_params->memcg_caches[idx];
- if (new_cachep)
+ if (new_cachep) {
+ css_put(&memcg->css);
goto out;
+ }
new_cachep = kmem_cache_dup(memcg, cachep);
if (new_cachep == NULL) {
new_cachep = cachep;
+ css_put(&memcg->css);
goto out;
}
- mem_cgroup_get(memcg);
atomic_set(&new_cachep->memcg_params->nr_pages , 0);
cachep->memcg_params->memcg_caches[idx] = new_cachep;
@@ -3480,8 +3491,6 @@
cw = container_of(w, struct create_work, work);
memcg_create_kmem_cache(cw->memcg, cw->cachep);
- /* Drop the reference gotten when we enqueued. */
- css_put(&cw->memcg->css);
kfree(cw);
}
@@ -3618,6 +3627,34 @@
int ret;
*_memcg = NULL;
+
+ /*
+ * Disabling accounting is only relevant for some specific memcg
+ * internal allocations. Therefore we would initially not have such
+ * check here, since direct calls to the page allocator that are marked
+ * with GFP_KMEMCG only happen outside memcg core. We are mostly
+ * concerned with cache allocations, and by having this test at
+ * memcg_kmem_get_cache, we are already able to relay the allocation to
+ * the root cache and bypass the memcg cache altogether.
+ *
+ * There is one exception, though: the SLUB allocator does not create
+ * large order caches, but rather service large kmallocs directly from
+ * the page allocator. Therefore, the following sequence when backed by
+ * the SLUB allocator:
+ *
+ * memcg_stop_kmem_account();
+ * kmalloc(<large_number>)
+ * memcg_resume_kmem_account();
+ *
+ * would effectively ignore the fact that we should skip accounting,
+ * since it will drive us directly to this function without passing
+ * through the cache selector memcg_kmem_get_cache. Such large
+ * allocations are extremely rare but can happen, for instance, for the
+ * cache arrays. We bring this test here.
+ */
+ if (!current->mm || current->memcg_kmem_skip_account)
+ return true;
+
memcg = try_get_mem_cgroup_from_mm(current->mm);
/*
@@ -4171,12 +4208,12 @@
unlock_page_cgroup(pc);
/*
* even after unlock, we have memcg->res.usage here and this memcg
- * will never be freed.
+ * will never be freed, so it's safe to call css_get().
*/
memcg_check_events(memcg, page);
if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) {
mem_cgroup_swap_statistics(memcg, true);
- mem_cgroup_get(memcg);
+ css_get(&memcg->css);
}
/*
* Migration does not charge the res_counter for the
@@ -4288,7 +4325,7 @@
/*
* record memcg information, if swapout && memcg != NULL,
- * mem_cgroup_get() was called in uncharge().
+ * css_get() was called in uncharge().
*/
if (do_swap_account && swapout && memcg)
swap_cgroup_record(ent, css_id(&memcg->css));
@@ -4319,7 +4356,7 @@
if (!mem_cgroup_is_root(memcg))
res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
mem_cgroup_swap_statistics(memcg, false);
- mem_cgroup_put(memcg);
+ css_put(&memcg->css);
}
rcu_read_unlock();
}
@@ -4353,11 +4390,14 @@
* This function is only called from task migration context now.
* It postpones res_counter and refcount handling till the end
* of task migration(mem_cgroup_clear_mc()) for performance
- * improvement. But we cannot postpone mem_cgroup_get(to)
- * because if the process that has been moved to @to does
- * swap-in, the refcount of @to might be decreased to 0.
+ * improvement. But we cannot postpone css_get(to) because if
+ * the process that has been moved to @to does swap-in, the
+ * refcount of @to might be decreased to 0.
+ *
+ * We are in attach() phase, so the cgroup is guaranteed to be
+ * alive, so we can just call css_get().
*/
- mem_cgroup_get(to);
+ css_get(&to->css);
return 0;
}
return -EINVAL;
@@ -5136,14 +5176,6 @@
* starts accounting before all call sites are patched
*/
memcg_kmem_set_active(memcg);
-
- /*
- * kmem charges can outlive the cgroup. In the case of slab
- * pages, for instance, a page contain objects from various
- * processes, so it is unfeasible to migrate them away. We
- * need to reference count the memcg because of that.
- */
- mem_cgroup_get(memcg);
} else
ret = res_counter_set_limit(&memcg->kmem, val);
out:
@@ -5176,16 +5208,16 @@
goto out;
/*
- * destroy(), called if we fail, will issue static_key_slow_inc() and
- * mem_cgroup_put() if kmem is enabled. We have to either call them
- * unconditionally, or clear the KMEM_ACTIVE flag. I personally find
- * this more consistent, since it always leads to the same destroy path
+ * __mem_cgroup_free() will issue static_key_slow_dec() because this
+ * memcg is active already. If the later initialization fails then the
+ * cgroup core triggers the cleanup so we do not have to do it here.
*/
- mem_cgroup_get(memcg);
static_key_slow_inc(&memcg_kmem_enabled_key);
mutex_lock(&set_limit_mutex);
+ memcg_stop_kmem_account();
ret = memcg_update_cache_sizes(memcg);
+ memcg_resume_kmem_account();
mutex_unlock(&set_limit_mutex);
out:
return ret;
@@ -5864,23 +5896,43 @@
return mem_cgroup_sockets_init(memcg, ss);
}
-static void kmem_cgroup_destroy(struct mem_cgroup *memcg)
+static void memcg_destroy_kmem(struct mem_cgroup *memcg)
{
mem_cgroup_sockets_destroy(memcg);
+}
+
+static void kmem_cgroup_css_offline(struct mem_cgroup *memcg)
+{
+ if (!memcg_kmem_is_active(memcg))
+ return;
+
+ /*
+ * kmem charges can outlive the cgroup. In the case of slab
+ * pages, for instance, a page contain objects from various
+ * processes. As we prevent from taking a reference for every
+ * such allocation we have to be careful when doing uncharge
+ * (see memcg_uncharge_kmem) and here during offlining.
+ *
+ * The idea is that that only the _last_ uncharge which sees
+ * the dead memcg will drop the last reference. An additional
+ * reference is taken here before the group is marked dead
+ * which is then paired with css_put during uncharge resp. here.
+ *
+ * Although this might sound strange as this path is called from
+ * css_offline() when the referencemight have dropped down to 0
+ * and shouldn't be incremented anymore (css_tryget would fail)
+ * we do not have other options because of the kmem allocations
+ * lifetime.
+ */
+ css_get(&memcg->css);
memcg_kmem_mark_dead(memcg);
if (res_counter_read_u64(&memcg->kmem, RES_USAGE) != 0)
return;
- /*
- * Charges already down to 0, undo mem_cgroup_get() done in the charge
- * path here, being careful not to race with memcg_uncharge_kmem: it is
- * possible that the charges went down to 0 between mark_dead and the
- * res_counter read, so in that case, we don't need the put
- */
if (memcg_kmem_test_and_clear_dead(memcg))
- mem_cgroup_put(memcg);
+ css_put(&memcg->css);
}
#else
static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
@@ -5888,7 +5940,11 @@
return 0;
}
-static void kmem_cgroup_destroy(struct mem_cgroup *memcg)
+static void memcg_destroy_kmem(struct mem_cgroup *memcg)
+{
+}
+
+static void kmem_cgroup_css_offline(struct mem_cgroup *memcg)
{
}
#endif
@@ -6058,13 +6114,13 @@
mz->on_tree = false;
mz->memcg = memcg;
}
- memcg->info.nodeinfo[node] = pn;
+ memcg->nodeinfo[node] = pn;
return 0;
}
static void free_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
{
- kfree(memcg->info.nodeinfo[node]);
+ kfree(memcg->nodeinfo[node]);
}
static struct mem_cgroup *mem_cgroup_alloc(void)
@@ -6137,49 +6193,6 @@
vfree(memcg);
}
-
-/*
- * Helpers for freeing a kmalloc()ed/vzalloc()ed mem_cgroup by RCU,
- * but in process context. The work_freeing structure is overlaid
- * on the rcu_freeing structure, which itself is overlaid on memsw.
- */
-static void free_work(struct work_struct *work)
-{
- struct mem_cgroup *memcg;
-
- memcg = container_of(work, struct mem_cgroup, work_freeing);
- __mem_cgroup_free(memcg);
-}
-
-static void free_rcu(struct rcu_head *rcu_head)
-{
- struct mem_cgroup *memcg;
-
- memcg = container_of(rcu_head, struct mem_cgroup, rcu_freeing);
- INIT_WORK(&memcg->work_freeing, free_work);
- schedule_work(&memcg->work_freeing);
-}
-
-static void mem_cgroup_get(struct mem_cgroup *memcg)
-{
- atomic_inc(&memcg->refcnt);
-}
-
-static void __mem_cgroup_put(struct mem_cgroup *memcg, int count)
-{
- if (atomic_sub_and_test(count, &memcg->refcnt)) {
- struct mem_cgroup *parent = parent_mem_cgroup(memcg);
- call_rcu(&memcg->rcu_freeing, free_rcu);
- if (parent)
- mem_cgroup_put(parent);
- }
-}
-
-static void mem_cgroup_put(struct mem_cgroup *memcg)
-{
- __mem_cgroup_put(memcg, 1);
-}
-
/*
* Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
*/
@@ -6239,7 +6252,6 @@
memcg->last_scanned_node = MAX_NUMNODES;
INIT_LIST_HEAD(&memcg->oom_notify);
- atomic_set(&memcg->refcnt, 1);
memcg->move_charge_at_immigrate = 0;
mutex_init(&memcg->thresholds_lock);
spin_lock_init(&memcg->move_lock);
@@ -6275,12 +6287,9 @@
res_counter_init(&memcg->kmem, &parent->kmem);
/*
- * We increment refcnt of the parent to ensure that we can
- * safely access it on res_counter_charge/uncharge.
- * This refcnt will be decremented when freeing this
- * mem_cgroup(see mem_cgroup_put).
+ * No need to take a reference to the parent because cgroup
+ * core guarantees its existence.
*/
- mem_cgroup_get(parent);
} else {
res_counter_init(&memcg->res, NULL);
res_counter_init(&memcg->memsw, NULL);
@@ -6296,16 +6305,6 @@
error = memcg_init_kmem(memcg, &mem_cgroup_subsys);
mutex_unlock(&memcg_create_mutex);
- if (error) {
- /*
- * We call put now because our (and parent's) refcnts
- * are already in place. mem_cgroup_put() will internally
- * call __mem_cgroup_free, so return directly
- */
- mem_cgroup_put(memcg);
- if (parent->use_hierarchy)
- mem_cgroup_put(parent);
- }
return error;
}
@@ -6317,20 +6316,22 @@
struct mem_cgroup *parent = memcg;
while ((parent = parent_mem_cgroup(parent)))
- atomic_inc(&parent->dead_count);
+ mem_cgroup_iter_invalidate(parent);
/*
* if the root memcg is not hierarchical we have to check it
* explicitely.
*/
if (!root_mem_cgroup->use_hierarchy)
- atomic_inc(&root_mem_cgroup->dead_count);
+ mem_cgroup_iter_invalidate(root_mem_cgroup);
}
static void mem_cgroup_css_offline(struct cgroup *cont)
{
struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
+ kmem_cgroup_css_offline(memcg);
+
mem_cgroup_invalidate_reclaim_iterators(memcg);
mem_cgroup_reparent_charges(memcg);
mem_cgroup_destroy_all_caches(memcg);
@@ -6340,9 +6341,8 @@
{
struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
- kmem_cgroup_destroy(memcg);
-
- mem_cgroup_put(memcg);
+ memcg_destroy_kmem(memcg);
+ __mem_cgroup_free(memcg);
}
#ifdef CONFIG_MMU
@@ -6651,6 +6651,7 @@
{
struct mem_cgroup *from = mc.from;
struct mem_cgroup *to = mc.to;
+ int i;
/* we must uncharge all the leftover precharges from mc.to */
if (mc.precharge) {
@@ -6671,7 +6672,9 @@
if (!mem_cgroup_is_root(mc.from))
res_counter_uncharge(&mc.from->memsw,
PAGE_SIZE * mc.moved_swap);
- __mem_cgroup_put(mc.from, mc.moved_swap);
+
+ for (i = 0; i < mc.moved_swap; i++)
+ css_put(&mc.from->css);
if (!mem_cgroup_is_root(mc.to)) {
/*
@@ -6681,7 +6684,7 @@
res_counter_uncharge(&mc.to->res,
PAGE_SIZE * mc.moved_swap);
}
- /* we've already done mem_cgroup_get(mc.to) */
+ /* we've already done css_get(mc.to) */
mc.moved_swap = 0;
}
memcg_oom_recover(from);
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index ceb0c7f..2c13aa7 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1410,7 +1410,8 @@
/*
* Isolate the page, so that it doesn't get reallocated if it
- * was free.
+ * was free. This flag should be kept set until the source page
+ * is freed and PG_hwpoison on it is set.
*/
set_migratetype_isolate(p, true);
/*
@@ -1433,7 +1434,6 @@
/* Not a free page */
ret = 1;
}
- unset_migratetype_isolate(p, MIGRATE_MOVABLE);
unlock_memory_hotplug();
return ret;
}
@@ -1494,7 +1494,6 @@
atomic_long_add(1 << compound_trans_order(hpage),
&num_poisoned_pages);
}
- /* keep elevated page count for bad page */
return ret;
}
@@ -1559,7 +1558,7 @@
atomic_long_inc(&num_poisoned_pages);
}
}
- /* keep elevated page count for bad page */
+ unset_migratetype_isolate(page, MIGRATE_MOVABLE);
return ret;
}
@@ -1625,7 +1624,22 @@
if (ret > 0)
ret = -EIO;
} else {
+ /*
+ * After page migration succeeds, the source page can
+ * be trapped in pagevec and actual freeing is delayed.
+ * Freeing code works differently based on PG_hwpoison,
+ * so there's a race. We need to make sure that the
+ * source page should be freed back to buddy before
+ * setting PG_hwpoison.
+ */
+ if (!is_free_buddy_page(page))
+ lru_add_drain_all();
+ if (!is_free_buddy_page(page))
+ drain_all_pages();
SetPageHWPoison(page);
+ if (!is_free_buddy_page(page))
+ pr_info("soft offline: %#lx: page leaked\n",
+ pfn);
atomic_long_inc(&num_poisoned_pages);
}
} else {
diff --git a/mm/memory.c b/mm/memory.c
index 95d0cce..1ce2e2a 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -82,7 +82,6 @@
EXPORT_SYMBOL(mem_map);
#endif
-unsigned long num_physpages;
/*
* A number of key systems in x86 including ioremap() rely on the assumption
* that high_memory defines the upper bound on direct map memory, then end
@@ -92,7 +91,6 @@
*/
void * high_memory;
-EXPORT_SYMBOL(num_physpages);
EXPORT_SYMBOL(high_memory);
/*
@@ -1101,6 +1099,7 @@
spinlock_t *ptl;
pte_t *start_pte;
pte_t *pte;
+ unsigned long range_start = addr;
again:
init_rss_vec(rss);
@@ -1151,7 +1150,7 @@
if (pte_dirty(ptent))
set_page_dirty(page);
if (pte_young(ptent) &&
- likely(!VM_SequentialReadHint(vma)))
+ likely(!(vma->vm_flags & VM_SEQ_READ)))
mark_page_accessed(page);
rss[MM_FILEPAGES]--;
}
@@ -1206,12 +1205,14 @@
force_flush = 0;
#ifdef HAVE_GENERIC_MMU_GATHER
- tlb->start = addr;
- tlb->end = end;
+ tlb->start = range_start;
+ tlb->end = addr;
#endif
tlb_flush_mmu(tlb);
- if (addr != end)
+ if (addr != end) {
+ range_start = addr;
goto again;
+ }
}
return addr;
@@ -2904,7 +2905,7 @@
details->first_index, details->last_index) {
vba = vma->vm_pgoff;
- vea = vba + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) - 1;
+ vea = vba + vma_pages(vma) - 1;
/* Assume for now that PAGE_CACHE_SHIFT == PAGE_SHIFT */
zba = details->first_index;
if (zba < vba)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 1ad92b4..ca1dd3a 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -75,7 +75,7 @@
res->end = start + size - 1;
res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
if (request_resource(&iomem_resource, res) < 0) {
- printk("System RAM resource %pR cannot be added\n", res);
+ pr_debug("System RAM resource %pR cannot be added\n", res);
kfree(res);
res = NULL;
}
@@ -101,12 +101,9 @@
atomic_inc(&page->_count);
}
-/* reference to __meminit __free_pages_bootmem is valid
- * so use __ref to tell modpost not to generate a warning */
-void __ref put_page_bootmem(struct page *page)
+void put_page_bootmem(struct page *page)
{
unsigned long type;
- static DEFINE_MUTEX(ppb_lock);
type = (unsigned long) page->lru.next;
BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
@@ -116,17 +113,8 @@
ClearPagePrivate(page);
set_page_private(page, 0);
INIT_LIST_HEAD(&page->lru);
-
- /*
- * Please refer to comment for __free_pages_bootmem()
- * for why we serialize here.
- */
- mutex_lock(&ppb_lock);
- __free_pages_bootmem(page, 0);
- mutex_unlock(&ppb_lock);
- totalram_pages++;
+ free_reserved_page(page);
}
-
}
#ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE
@@ -220,13 +208,13 @@
pfn = pgdat->node_start_pfn;
end_pfn = pgdat_end_pfn(pgdat);
- /* register_section info */
+ /* register section info */
for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
/*
* Some platforms can assign the same pfn to multiple nodes - on
* node0 as well as nodeN. To avoid registering a pfn against
* multiple nodes we check that this pfn does not already
- * reside in some other node.
+ * reside in some other nodes.
*/
if (pfn_valid(pfn) && (pfn_to_nid(pfn) == node))
register_page_bootmem_info_section(pfn);
@@ -309,7 +297,7 @@
/* can't move pfns which are higher than @z2 */
if (end_pfn > zone_end_pfn(z2))
goto out_fail;
- /* the move out part mast at the left most of @z2 */
+ /* the move out part must be at the left most of @z2 */
if (start_pfn > z2->zone_start_pfn)
goto out_fail;
/* must included/overlap */
@@ -775,29 +763,18 @@
void __online_page_set_limits(struct page *page)
{
- unsigned long pfn = page_to_pfn(page);
-
- if (pfn >= num_physpages)
- num_physpages = pfn + 1;
}
EXPORT_SYMBOL_GPL(__online_page_set_limits);
void __online_page_increment_counters(struct page *page)
{
- totalram_pages++;
-
-#ifdef CONFIG_HIGHMEM
- if (PageHighMem(page))
- totalhigh_pages++;
-#endif
+ adjust_managed_page_count(page, 1);
}
EXPORT_SYMBOL_GPL(__online_page_increment_counters);
void __online_page_free(struct page *page)
{
- ClearPageReserved(page);
- init_page_count(page);
- __free_page(page);
+ __free_reserved_page(page);
}
EXPORT_SYMBOL_GPL(__online_page_free);
@@ -918,6 +895,7 @@
int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_type)
{
+ unsigned long flags;
unsigned long onlined_pages = 0;
struct zone *zone;
int need_zonelists_rebuild = 0;
@@ -936,19 +914,19 @@
if ((zone_idx(zone) > ZONE_NORMAL || online_type == ONLINE_MOVABLE) &&
!can_online_high_movable(zone)) {
unlock_memory_hotplug();
- return -1;
+ return -EINVAL;
}
if (online_type == ONLINE_KERNEL && zone_idx(zone) == ZONE_MOVABLE) {
if (move_pfn_range_left(zone - 1, zone, pfn, pfn + nr_pages)) {
unlock_memory_hotplug();
- return -1;
+ return -EINVAL;
}
}
if (online_type == ONLINE_MOVABLE && zone_idx(zone) == ZONE_MOVABLE - 1) {
if (move_pfn_range_right(zone, zone + 1, pfn, pfn + nr_pages)) {
unlock_memory_hotplug();
- return -1;
+ return -EINVAL;
}
}
@@ -994,9 +972,12 @@
return ret;
}
- zone->managed_pages += onlined_pages;
zone->present_pages += onlined_pages;
+
+ pgdat_resize_lock(zone->zone_pgdat, &flags);
zone->zone_pgdat->node_present_pages += onlined_pages;
+ pgdat_resize_unlock(zone->zone_pgdat, &flags);
+
if (onlined_pages) {
node_states_set_node(zone_to_nid(zone), &arg);
if (need_zonelists_rebuild)
@@ -1487,6 +1468,7 @@
unsigned long pfn, nr_pages, expire;
long offlined_pages;
int ret, drain, retry_max, node;
+ unsigned long flags;
struct zone *zone;
struct memory_notify arg;
@@ -1578,10 +1560,12 @@
/* reset pagetype flags and makes migrate type to be MOVABLE */
undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE);
/* removal success */
- zone->managed_pages -= offlined_pages;
+ adjust_managed_page_count(pfn_to_page(start_pfn), -offlined_pages);
zone->present_pages -= offlined_pages;
+
+ pgdat_resize_lock(zone->zone_pgdat, &flags);
zone->zone_pgdat->node_present_pages -= offlined_pages;
- totalram_pages -= offlined_pages;
+ pgdat_resize_unlock(zone->zone_pgdat, &flags);
init_per_zone_wmark_min();
@@ -1621,6 +1605,7 @@
{
return __offline_pages(start_pfn, start_pfn + nr_pages, 120 * HZ);
}
+#endif /* CONFIG_MEMORY_HOTREMOVE */
/**
* walk_memory_range - walks through all mem sections in [start_pfn, end_pfn)
@@ -1634,7 +1619,7 @@
*
* Returns the return value of func.
*/
-static int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn,
+int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn,
void *arg, int (*func)(struct memory_block *, void *))
{
struct memory_block *mem = NULL;
@@ -1671,24 +1656,7 @@
return 0;
}
-/**
- * offline_memory_block_cb - callback function for offlining memory block
- * @mem: the memory block to be offlined
- * @arg: buffer to hold error msg
- *
- * Always return 0, and put the error msg in arg if any.
- */
-static int offline_memory_block_cb(struct memory_block *mem, void *arg)
-{
- int *ret = arg;
- int error = offline_memory_block(mem);
-
- if (error != 0 && *ret == 0)
- *ret = error;
-
- return 0;
-}
-
+#ifdef CONFIG_MEMORY_HOTREMOVE
static int is_memblock_offlined_cb(struct memory_block *mem, void *arg)
{
int ret = !is_memblock_offlined(mem);
@@ -1814,54 +1782,22 @@
}
EXPORT_SYMBOL(try_offline_node);
-int __ref remove_memory(int nid, u64 start, u64 size)
+void __ref remove_memory(int nid, u64 start, u64 size)
{
- unsigned long start_pfn, end_pfn;
- int ret = 0;
- int retry = 1;
-
- start_pfn = PFN_DOWN(start);
- end_pfn = PFN_UP(start + size - 1);
-
- /*
- * When CONFIG_MEMCG is on, one memory block may be used by other
- * blocks to store page cgroup when onlining pages. But we don't know
- * in what order pages are onlined. So we iterate twice to offline
- * memory:
- * 1st iterate: offline every non primary memory block.
- * 2nd iterate: offline primary (i.e. first added) memory block.
- */
-repeat:
- walk_memory_range(start_pfn, end_pfn, &ret,
- offline_memory_block_cb);
- if (ret) {
- if (!retry)
- return ret;
-
- retry = 0;
- ret = 0;
- goto repeat;
- }
+ int ret;
lock_memory_hotplug();
/*
- * we have offlined all memory blocks like this:
- * 1. lock memory hotplug
- * 2. offline a memory block
- * 3. unlock memory hotplug
- *
- * repeat step1-3 to offline the memory block. All memory blocks
- * must be offlined before removing memory. But we don't hold the
- * lock in the whole operation. So we should check whether all
- * memory blocks are offlined.
+ * All memory blocks must be offlined before removing memory. Check
+ * whether all memory blocks in question are offline and trigger a BUG()
+ * if this is not the case.
*/
-
- ret = walk_memory_range(start_pfn, end_pfn, NULL,
+ ret = walk_memory_range(PFN_DOWN(start), PFN_UP(start + size - 1), NULL,
is_memblock_offlined_cb);
if (ret) {
unlock_memory_hotplug();
- return ret;
+ BUG();
}
/* remove memmap entry */
@@ -1872,17 +1808,6 @@
try_offline_node(nid);
unlock_memory_hotplug();
-
- return 0;
}
-#else
-int offline_pages(unsigned long start_pfn, unsigned long nr_pages)
-{
- return -EINVAL;
-}
-int remove_memory(int nid, u64 start, u64 size)
-{
- return -EINVAL;
-}
-#endif /* CONFIG_MEMORY_HOTREMOVE */
EXPORT_SYMBOL_GPL(remove_memory);
+#endif /* CONFIG_MEMORY_HOTREMOVE */
diff --git a/mm/mm_init.c b/mm/mm_init.c
index c280a02..633c088 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -9,6 +9,8 @@
#include <linux/init.h>
#include <linux/kobject.h>
#include <linux/export.h>
+#include <linux/memory.h>
+#include <linux/notifier.h>
#include "internal.h"
#ifdef CONFIG_DEBUG_MEMORY_INIT
@@ -147,6 +149,51 @@
struct kobject *mm_kobj;
EXPORT_SYMBOL_GPL(mm_kobj);
+#ifdef CONFIG_SMP
+s32 vm_committed_as_batch = 32;
+
+static void __meminit mm_compute_batch(void)
+{
+ u64 memsized_batch;
+ s32 nr = num_present_cpus();
+ s32 batch = max_t(s32, nr*2, 32);
+
+ /* batch size set to 0.4% of (total memory/#cpus), or max int32 */
+ memsized_batch = min_t(u64, (totalram_pages/nr)/256, 0x7fffffff);
+
+ vm_committed_as_batch = max_t(s32, memsized_batch, batch);
+}
+
+static int __meminit mm_compute_batch_notifier(struct notifier_block *self,
+ unsigned long action, void *arg)
+{
+ switch (action) {
+ case MEM_ONLINE:
+ case MEM_OFFLINE:
+ mm_compute_batch();
+ default:
+ break;
+ }
+ return NOTIFY_OK;
+}
+
+static struct notifier_block compute_batch_nb __meminitdata = {
+ .notifier_call = mm_compute_batch_notifier,
+ .priority = IPC_CALLBACK_PRI, /* use lowest priority */
+};
+
+static int __init mm_compute_batch_init(void)
+{
+ mm_compute_batch();
+ register_hotmemory_notifier(&compute_batch_nb);
+
+ return 0;
+}
+
+__initcall(mm_compute_batch_init);
+
+#endif
+
static int __init mm_sysfs_init(void)
{
mm_kobj = kobject_create_and_add("mm", kernel_kobj);
diff --git a/mm/mmap.c b/mm/mmap.c
index f681e18..fbad7b0 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -955,7 +955,7 @@
if (is_mergeable_vma(vma, file, vm_flags) &&
is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) {
pgoff_t vm_pglen;
- vm_pglen = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
+ vm_pglen = vma_pages(vma);
if (vma->vm_pgoff + vm_pglen == vm_pgoff)
return 1;
}
@@ -1358,18 +1358,19 @@
if (!(flags & MAP_ANONYMOUS)) {
audit_mmap_fd(fd, flags);
- if (unlikely(flags & MAP_HUGETLB))
- return -EINVAL;
file = fget(fd);
if (!file)
goto out;
if (is_file_hugepages(file))
len = ALIGN(len, huge_page_size(hstate_file(file)));
+ retval = -EINVAL;
+ if (unlikely(flags & MAP_HUGETLB && !is_file_hugepages(file)))
+ goto out_fput;
} else if (flags & MAP_HUGETLB) {
struct user_struct *user = NULL;
- struct hstate *hs = hstate_sizelog((flags >> MAP_HUGE_SHIFT) &
- SHM_HUGE_MASK);
+ struct hstate *hs;
+ hs = hstate_sizelog((flags >> MAP_HUGE_SHIFT) & SHM_HUGE_MASK);
if (!hs)
return -EINVAL;
@@ -1391,6 +1392,7 @@
flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff);
+out_fput:
if (file)
fput(file);
out:
@@ -1876,15 +1878,6 @@
}
#endif
-void arch_unmap_area(struct mm_struct *mm, unsigned long addr)
-{
- /*
- * Is this a new hole at the lowest possible address?
- */
- if (addr >= TASK_UNMAPPED_BASE && addr < mm->free_area_cache)
- mm->free_area_cache = addr;
-}
-
/*
* This mmap-allocator allocates new areas top-down from below the
* stack's low limit (the base):
@@ -1941,19 +1934,6 @@
}
#endif
-void arch_unmap_area_topdown(struct mm_struct *mm, unsigned long addr)
-{
- /*
- * Is this a new hole at the highest possible address?
- */
- if (addr > mm->free_area_cache)
- mm->free_area_cache = addr;
-
- /* dont allow allocations above current base */
- if (mm->free_area_cache > mm->mmap_base)
- mm->free_area_cache = mm->mmap_base;
-}
-
unsigned long
get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
unsigned long pgoff, unsigned long flags)
@@ -2374,7 +2354,6 @@
{
struct vm_area_struct **insertion_point;
struct vm_area_struct *tail_vma = NULL;
- unsigned long addr;
insertion_point = (prev ? &prev->vm_next : &mm->mmap);
vma->vm_prev = NULL;
@@ -2391,11 +2370,6 @@
} else
mm->highest_vm_end = prev ? prev->vm_end : 0;
tail_vma->vm_next = NULL;
- if (mm->unmap_area == arch_unmap_area)
- addr = prev ? prev->vm_end : mm->mmap_base;
- else
- addr = vma ? vma->vm_start : mm->mmap_base;
- mm->unmap_area(mm, addr);
mm->mmap_cache = NULL; /* Kill the cache. */
}
diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c
index 6725ff1..93e6089 100644
--- a/mm/mmu_notifier.c
+++ b/mm/mmu_notifier.c
@@ -315,7 +315,7 @@
/*
* Wait for any running method to finish, of course including
- * ->release if it was run by mmu_notifier_relase instead of us.
+ * ->release if it was run by mmu_notifier_release instead of us.
*/
synchronize_srcu(&srcu);
diff --git a/mm/mremap.c b/mm/mremap.c
index 463a257..457d34e 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -126,7 +126,7 @@
continue;
pte = ptep_get_and_clear(mm, old_addr, old_pte);
pte = move_pte(pte, new_vma->vm_page_prot, old_addr, new_addr);
- set_pte_at(mm, new_addr, new_pte, pte);
+ set_pte_at(mm, new_addr, new_pte, pte_mksoft_dirty(pte));
}
arch_leave_lazy_mmu_mode();
@@ -456,13 +456,14 @@
unsigned long charged = 0;
bool locked = false;
- down_write(¤t->mm->mmap_sem);
-
if (flags & ~(MREMAP_FIXED | MREMAP_MAYMOVE))
- goto out;
+ return ret;
+
+ if (flags & MREMAP_FIXED && !(flags & MREMAP_MAYMOVE))
+ return ret;
if (addr & ~PAGE_MASK)
- goto out;
+ return ret;
old_len = PAGE_ALIGN(old_len);
new_len = PAGE_ALIGN(new_len);
@@ -473,12 +474,13 @@
* a zero new-len is nonsensical.
*/
if (!new_len)
- goto out;
+ return ret;
+
+ down_write(¤t->mm->mmap_sem);
if (flags & MREMAP_FIXED) {
- if (flags & MREMAP_MAYMOVE)
- ret = mremap_to(addr, old_len, new_addr, new_len,
- &locked);
+ ret = mremap_to(addr, old_len, new_addr, new_len,
+ &locked);
goto out;
}
diff --git a/mm/nobootmem.c b/mm/nobootmem.c
index bdd3fa2..61107cf 100644
--- a/mm/nobootmem.c
+++ b/mm/nobootmem.c
@@ -137,20 +137,25 @@
return count;
}
-static void reset_node_lowmem_managed_pages(pg_data_t *pgdat)
+static int reset_managed_pages_done __initdata;
+
+static inline void __init reset_node_managed_pages(pg_data_t *pgdat)
{
struct zone *z;
- /*
- * In free_area_init_core(), highmem zone's managed_pages is set to
- * present_pages, and bootmem allocator doesn't allocate from highmem
- * zones. So there's no need to recalculate managed_pages because all
- * highmem pages will be managed by the buddy system. Here highmem
- * zone also includes highmem movable zone.
- */
+ if (reset_managed_pages_done)
+ return;
for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
- if (!is_highmem(z))
- z->managed_pages = 0;
+ z->managed_pages = 0;
+}
+
+void __init reset_all_zones_managed_pages(void)
+{
+ struct pglist_data *pgdat;
+
+ for_each_online_pgdat(pgdat)
+ reset_node_managed_pages(pgdat);
+ reset_managed_pages_done = 1;
}
/**
@@ -160,17 +165,19 @@
*/
unsigned long __init free_all_bootmem(void)
{
- struct pglist_data *pgdat;
+ unsigned long pages;
- for_each_online_pgdat(pgdat)
- reset_node_lowmem_managed_pages(pgdat);
+ reset_all_zones_managed_pages();
/*
* We need to use MAX_NUMNODES instead of NODE_DATA(0)->node_id
* because in some case like Node0 doesn't have RAM installed
* low ram will be on Node1
*/
- return free_low_memory_core_early();
+ pages = free_low_memory_core_early();
+ totalram_pages += pages;
+
+ return pages;
}
/**
diff --git a/mm/nommu.c b/mm/nommu.c
index 298884d..ecd1f15 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -56,7 +56,6 @@
void *high_memory;
struct page *mem_map;
unsigned long max_mapnr;
-unsigned long num_physpages;
unsigned long highest_memmap_pfn;
struct percpu_counter vm_committed_as;
int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */
@@ -85,7 +84,6 @@
EXPORT_SYMBOL_GPL(vm_memory_committed);
EXPORT_SYMBOL(mem_map);
-EXPORT_SYMBOL(num_physpages);
/* list of mapped, potentially shareable regions */
static struct kmem_cache *vm_region_jar;
@@ -282,6 +280,10 @@
long vread(char *buf, char *addr, unsigned long count)
{
+ /* Don't allow overflow */
+ if ((unsigned long) buf + count < count)
+ count = -(unsigned long) buf;
+
memcpy(buf, addr, count);
return count;
}
@@ -1869,10 +1871,6 @@
return -ENOMEM;
}
-void arch_unmap_area(struct mm_struct *mm, unsigned long addr)
-{
-}
-
void unmap_mapping_range(struct address_space *mapping,
loff_t const holebegin, loff_t const holelen,
int even_cows)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index c3edb62..b100255 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -61,10 +61,14 @@
#include <linux/hugetlb.h>
#include <linux/sched/rt.h>
+#include <asm/sections.h>
#include <asm/tlbflush.h>
#include <asm/div64.h>
#include "internal.h"
+/* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
+static DEFINE_MUTEX(pcp_batch_high_lock);
+
#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
DEFINE_PER_CPU(int, numa_node);
EXPORT_PER_CPU_SYMBOL(numa_node);
@@ -100,6 +104,9 @@
};
EXPORT_SYMBOL(node_states);
+/* Protect totalram_pages and zone->managed_pages */
+static DEFINE_SPINLOCK(managed_page_count_lock);
+
unsigned long totalram_pages __read_mostly;
unsigned long totalreserve_pages __read_mostly;
/*
@@ -197,6 +204,7 @@
};
int min_free_kbytes = 1024;
+int user_min_free_kbytes;
static unsigned long __meminitdata nr_kernel_pages;
static unsigned long __meminitdata nr_all_pages;
@@ -739,14 +747,7 @@
local_irq_restore(flags);
}
-/*
- * Read access to zone->managed_pages is safe because it's unsigned long,
- * but we still need to serialize writers. Currently all callers of
- * __free_pages_bootmem() except put_page_bootmem() should only be used
- * at boot time. So for shorter boot time, we shift the burden to
- * put_page_bootmem() to serialize writers.
- */
-void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
+void __init __free_pages_bootmem(struct page *page, unsigned int order)
{
unsigned int nr_pages = 1 << order;
unsigned int loop;
@@ -781,11 +782,7 @@
set_page_refcounted(page);
set_pageblock_migratetype(page, MIGRATE_CMA);
__free_pages(page, pageblock_order);
- totalram_pages += pageblock_nr_pages;
-#ifdef CONFIG_HIGHMEM
- if (PageHighMem(page))
- totalhigh_pages += pageblock_nr_pages;
-#endif
+ adjust_managed_page_count(page, pageblock_nr_pages);
}
#endif
@@ -1050,7 +1047,7 @@
* MIGRATE_CMA areas.
*/
if (!is_migrate_cma(migratetype) &&
- (unlikely(current_order >= pageblock_order / 2) ||
+ (current_order >= pageblock_order / 2 ||
start_migratetype == MIGRATE_RECLAIMABLE ||
page_group_by_mobility_disabled)) {
int pages;
@@ -1179,10 +1176,12 @@
{
unsigned long flags;
int to_drain;
+ unsigned long batch;
local_irq_save(flags);
- if (pcp->count >= pcp->batch)
- to_drain = pcp->batch;
+ batch = ACCESS_ONCE(pcp->batch);
+ if (pcp->count >= batch)
+ to_drain = batch;
else
to_drain = pcp->count;
if (to_drain > 0) {
@@ -1350,8 +1349,9 @@
list_add(&page->lru, &pcp->lists[migratetype]);
pcp->count++;
if (pcp->count >= pcp->high) {
- free_pcppages_bulk(zone, pcp->batch, pcp);
- pcp->count -= pcp->batch;
+ unsigned long batch = ACCESS_ONCE(pcp->batch);
+ free_pcppages_bulk(zone, batch, pcp);
+ pcp->count -= batch;
}
out:
@@ -2839,7 +2839,7 @@
* nr_free_zone_pages() counts the number of counts pages which are beyond the
* high watermark within all zones at or below a given zone index. For each
* zone, the number of pages is calculated as:
- * present_pages - high_pages
+ * managed_pages - high_pages
*/
static unsigned long nr_free_zone_pages(int offset)
{
@@ -2906,9 +2906,13 @@
#ifdef CONFIG_NUMA
void si_meminfo_node(struct sysinfo *val, int nid)
{
+ int zone_type; /* needs to be signed */
+ unsigned long managed_pages = 0;
pg_data_t *pgdat = NODE_DATA(nid);
- val->totalram = pgdat->node_present_pages;
+ for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
+ managed_pages += pgdat->node_zones[zone_type].managed_pages;
+ val->totalram = managed_pages;
val->freeram = node_page_state(nid, NR_FREE_PAGES);
#ifdef CONFIG_HIGHMEM
val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].managed_pages;
@@ -3150,12 +3154,10 @@
* Add all populated zones of a node to the zonelist.
*/
static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
- int nr_zones, enum zone_type zone_type)
+ int nr_zones)
{
struct zone *zone;
-
- BUG_ON(zone_type >= MAX_NR_ZONES);
- zone_type++;
+ enum zone_type zone_type = MAX_NR_ZONES;
do {
zone_type--;
@@ -3165,8 +3167,8 @@
&zonelist->_zonerefs[nr_zones++]);
check_highest_zone(zone_type);
}
-
} while (zone_type);
+
return nr_zones;
}
@@ -3250,18 +3252,25 @@
static DEFINE_MUTEX(zl_order_mutex);
mutex_lock(&zl_order_mutex);
- if (write)
- strcpy(saved_string, (char*)table->data);
+ if (write) {
+ if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) {
+ ret = -EINVAL;
+ goto out;
+ }
+ strcpy(saved_string, (char *)table->data);
+ }
ret = proc_dostring(table, write, buffer, length, ppos);
if (ret)
goto out;
if (write) {
int oldval = user_zonelist_order;
- if (__parse_numa_zonelist_order((char*)table->data)) {
+
+ ret = __parse_numa_zonelist_order((char *)table->data);
+ if (ret) {
/*
* bogus value. restore saved string
*/
- strncpy((char*)table->data, saved_string,
+ strncpy((char *)table->data, saved_string,
NUMA_ZONELIST_ORDER_LEN);
user_zonelist_order = oldval;
} else if (oldval != user_zonelist_order) {
@@ -3353,8 +3362,7 @@
zonelist = &pgdat->node_zonelists[0];
for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
;
- j = build_zonelists_node(NODE_DATA(node), zonelist, j,
- MAX_NR_ZONES - 1);
+ j = build_zonelists_node(NODE_DATA(node), zonelist, j);
zonelist->_zonerefs[j].zone = NULL;
zonelist->_zonerefs[j].zone_idx = 0;
}
@@ -3368,7 +3376,7 @@
struct zonelist *zonelist;
zonelist = &pgdat->node_zonelists[1];
- j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
+ j = build_zonelists_node(pgdat, zonelist, 0);
zonelist->_zonerefs[j].zone = NULL;
zonelist->_zonerefs[j].zone_idx = 0;
}
@@ -3425,8 +3433,8 @@
z = &NODE_DATA(nid)->node_zones[zone_type];
if (populated_zone(z)) {
if (zone_type < ZONE_NORMAL)
- low_kmem_size += z->present_pages;
- total_size += z->present_pages;
+ low_kmem_size += z->managed_pages;
+ total_size += z->managed_pages;
} else if (zone_type == ZONE_NORMAL) {
/*
* If any node has only lowmem, then node order
@@ -3576,7 +3584,7 @@
local_node = pgdat->node_id;
zonelist = &pgdat->node_zonelists[0];
- j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
+ j = build_zonelists_node(pgdat, zonelist, 0);
/*
* Now we build the zonelist so that it contains the zones
@@ -3589,14 +3597,12 @@
for (node = local_node + 1; node < MAX_NUMNODES; node++) {
if (!node_online(node))
continue;
- j = build_zonelists_node(NODE_DATA(node), zonelist, j,
- MAX_NR_ZONES - 1);
+ j = build_zonelists_node(NODE_DATA(node), zonelist, j);
}
for (node = 0; node < local_node; node++) {
if (!node_online(node))
continue;
- j = build_zonelists_node(NODE_DATA(node), zonelist, j,
- MAX_NR_ZONES - 1);
+ j = build_zonelists_node(NODE_DATA(node), zonelist, j);
}
zonelist->_zonerefs[j].zone = NULL;
@@ -3705,12 +3711,12 @@
mminit_verify_zonelist();
cpuset_init_current_mems_allowed();
} else {
- /* we have to stop all cpus to guarantee there is no user
- of zonelist */
#ifdef CONFIG_MEMORY_HOTPLUG
if (zone)
setup_zone_pageset(zone);
#endif
+ /* we have to stop all cpus to guarantee there is no user
+ of zonelist */
stop_machine(__build_all_zonelists, pgdat, NULL);
/* cpuset refresh routine should be here */
}
@@ -4032,7 +4038,40 @@
#endif
}
-static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
+/*
+ * pcp->high and pcp->batch values are related and dependent on one another:
+ * ->batch must never be higher then ->high.
+ * The following function updates them in a safe manner without read side
+ * locking.
+ *
+ * Any new users of pcp->batch and pcp->high should ensure they can cope with
+ * those fields changing asynchronously (acording the the above rule).
+ *
+ * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
+ * outside of boot time (or some other assurance that no concurrent updaters
+ * exist).
+ */
+static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
+ unsigned long batch)
+{
+ /* start with a fail safe value for batch */
+ pcp->batch = 1;
+ smp_wmb();
+
+ /* Update high, then batch, in order */
+ pcp->high = high;
+ smp_wmb();
+
+ pcp->batch = batch;
+}
+
+/* a companion to pageset_set_high() */
+static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch)
+{
+ pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch));
+}
+
+static void pageset_init(struct per_cpu_pageset *p)
{
struct per_cpu_pages *pcp;
int migratetype;
@@ -4041,45 +4080,55 @@
pcp = &p->pcp;
pcp->count = 0;
- pcp->high = 6 * batch;
- pcp->batch = max(1UL, 1 * batch);
for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
INIT_LIST_HEAD(&pcp->lists[migratetype]);
}
+static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
+{
+ pageset_init(p);
+ pageset_set_batch(p, batch);
+}
+
/*
- * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
+ * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
* to the value high for the pageset p.
*/
-
-static void setup_pagelist_highmark(struct per_cpu_pageset *p,
+static void pageset_set_high(struct per_cpu_pageset *p,
unsigned long high)
{
- struct per_cpu_pages *pcp;
+ unsigned long batch = max(1UL, high / 4);
+ if ((high / 4) > (PAGE_SHIFT * 8))
+ batch = PAGE_SHIFT * 8;
- pcp = &p->pcp;
- pcp->high = high;
- pcp->batch = max(1UL, high/4);
- if ((high/4) > (PAGE_SHIFT * 8))
- pcp->batch = PAGE_SHIFT * 8;
+ pageset_update(&p->pcp, high, batch);
+}
+
+static void __meminit pageset_set_high_and_batch(struct zone *zone,
+ struct per_cpu_pageset *pcp)
+{
+ if (percpu_pagelist_fraction)
+ pageset_set_high(pcp,
+ (zone->managed_pages /
+ percpu_pagelist_fraction));
+ else
+ pageset_set_batch(pcp, zone_batchsize(zone));
+}
+
+static void __meminit zone_pageset_init(struct zone *zone, int cpu)
+{
+ struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
+
+ pageset_init(pcp);
+ pageset_set_high_and_batch(zone, pcp);
}
static void __meminit setup_zone_pageset(struct zone *zone)
{
int cpu;
-
zone->pageset = alloc_percpu(struct per_cpu_pageset);
-
- for_each_possible_cpu(cpu) {
- struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
-
- setup_pageset(pcp, zone_batchsize(zone));
-
- if (percpu_pagelist_fraction)
- setup_pagelist_highmark(pcp,
- (zone->managed_pages /
- percpu_pagelist_fraction));
- }
+ for_each_possible_cpu(cpu)
+ zone_pageset_init(zone, cpu);
}
/*
@@ -4368,13 +4417,13 @@
*/
static unsigned long __meminit zone_spanned_pages_in_node(int nid,
unsigned long zone_type,
+ unsigned long node_start_pfn,
+ unsigned long node_end_pfn,
unsigned long *ignored)
{
- unsigned long node_start_pfn, node_end_pfn;
unsigned long zone_start_pfn, zone_end_pfn;
- /* Get the start and end of the node and zone */
- get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
+ /* Get the start and end of the zone */
zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
adjust_zone_range_for_zone_movable(nid, zone_type,
@@ -4429,14 +4478,14 @@
/* Return the number of page frames in holes in a zone on a node */
static unsigned long __meminit zone_absent_pages_in_node(int nid,
unsigned long zone_type,
+ unsigned long node_start_pfn,
+ unsigned long node_end_pfn,
unsigned long *ignored)
{
unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
- unsigned long node_start_pfn, node_end_pfn;
unsigned long zone_start_pfn, zone_end_pfn;
- get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
@@ -4449,6 +4498,8 @@
#else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
unsigned long zone_type,
+ unsigned long node_start_pfn,
+ unsigned long node_end_pfn,
unsigned long *zones_size)
{
return zones_size[zone_type];
@@ -4456,6 +4507,8 @@
static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
unsigned long zone_type,
+ unsigned long node_start_pfn,
+ unsigned long node_end_pfn,
unsigned long *zholes_size)
{
if (!zholes_size)
@@ -4467,21 +4520,27 @@
#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
- unsigned long *zones_size, unsigned long *zholes_size)
+ unsigned long node_start_pfn,
+ unsigned long node_end_pfn,
+ unsigned long *zones_size,
+ unsigned long *zholes_size)
{
unsigned long realtotalpages, totalpages = 0;
enum zone_type i;
for (i = 0; i < MAX_NR_ZONES; i++)
totalpages += zone_spanned_pages_in_node(pgdat->node_id, i,
- zones_size);
+ node_start_pfn,
+ node_end_pfn,
+ zones_size);
pgdat->node_spanned_pages = totalpages;
realtotalpages = totalpages;
for (i = 0; i < MAX_NR_ZONES; i++)
realtotalpages -=
zone_absent_pages_in_node(pgdat->node_id, i,
- zholes_size);
+ node_start_pfn, node_end_pfn,
+ zholes_size);
pgdat->node_present_pages = realtotalpages;
printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
realtotalpages);
@@ -4590,6 +4649,7 @@
* NOTE: pgdat should get zeroed by caller.
*/
static void __paginginit free_area_init_core(struct pglist_data *pgdat,
+ unsigned long node_start_pfn, unsigned long node_end_pfn,
unsigned long *zones_size, unsigned long *zholes_size)
{
enum zone_type j;
@@ -4611,8 +4671,11 @@
struct zone *zone = pgdat->node_zones + j;
unsigned long size, realsize, freesize, memmap_pages;
- size = zone_spanned_pages_in_node(nid, j, zones_size);
+ size = zone_spanned_pages_in_node(nid, j, node_start_pfn,
+ node_end_pfn, zones_size);
realsize = freesize = size - zone_absent_pages_in_node(nid, j,
+ node_start_pfn,
+ node_end_pfn,
zholes_size);
/*
@@ -4726,6 +4789,8 @@
unsigned long node_start_pfn, unsigned long *zholes_size)
{
pg_data_t *pgdat = NODE_DATA(nid);
+ unsigned long start_pfn = 0;
+ unsigned long end_pfn = 0;
/* pg_data_t should be reset to zero when it's allocated */
WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
@@ -4733,7 +4798,11 @@
pgdat->node_id = nid;
pgdat->node_start_pfn = node_start_pfn;
init_zone_allows_reclaim(nid);
- calculate_node_totalpages(pgdat, zones_size, zholes_size);
+#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
+ get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
+#endif
+ calculate_node_totalpages(pgdat, start_pfn, end_pfn,
+ zones_size, zholes_size);
alloc_node_mem_map(pgdat);
#ifdef CONFIG_FLAT_NODE_MEM_MAP
@@ -4742,7 +4811,8 @@
(unsigned long)pgdat->node_mem_map);
#endif
- free_area_init_core(pgdat, zones_size, zholes_size);
+ free_area_init_core(pgdat, start_pfn, end_pfn,
+ zones_size, zholes_size);
}
#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
@@ -5150,35 +5220,101 @@
#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
-unsigned long free_reserved_area(unsigned long start, unsigned long end,
- int poison, char *s)
+void adjust_managed_page_count(struct page *page, long count)
{
- unsigned long pages, pos;
+ spin_lock(&managed_page_count_lock);
+ page_zone(page)->managed_pages += count;
+ totalram_pages += count;
+#ifdef CONFIG_HIGHMEM
+ if (PageHighMem(page))
+ totalhigh_pages += count;
+#endif
+ spin_unlock(&managed_page_count_lock);
+}
+EXPORT_SYMBOL(adjust_managed_page_count);
- pos = start = PAGE_ALIGN(start);
- end &= PAGE_MASK;
- for (pages = 0; pos < end; pos += PAGE_SIZE, pages++) {
- if (poison)
- memset((void *)pos, poison, PAGE_SIZE);
- free_reserved_page(virt_to_page((void *)pos));
+unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
+{
+ void *pos;
+ unsigned long pages = 0;
+
+ start = (void *)PAGE_ALIGN((unsigned long)start);
+ end = (void *)((unsigned long)end & PAGE_MASK);
+ for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
+ if ((unsigned int)poison <= 0xFF)
+ memset(pos, poison, PAGE_SIZE);
+ free_reserved_page(virt_to_page(pos));
}
if (pages && s)
- pr_info("Freeing %s memory: %ldK (%lx - %lx)\n",
+ pr_info("Freeing %s memory: %ldK (%p - %p)\n",
s, pages << (PAGE_SHIFT - 10), start, end);
return pages;
}
+EXPORT_SYMBOL(free_reserved_area);
#ifdef CONFIG_HIGHMEM
void free_highmem_page(struct page *page)
{
__free_reserved_page(page);
totalram_pages++;
+ page_zone(page)->managed_pages++;
totalhigh_pages++;
}
#endif
+
+void __init mem_init_print_info(const char *str)
+{
+ unsigned long physpages, codesize, datasize, rosize, bss_size;
+ unsigned long init_code_size, init_data_size;
+
+ physpages = get_num_physpages();
+ codesize = _etext - _stext;
+ datasize = _edata - _sdata;
+ rosize = __end_rodata - __start_rodata;
+ bss_size = __bss_stop - __bss_start;
+ init_data_size = __init_end - __init_begin;
+ init_code_size = _einittext - _sinittext;
+
+ /*
+ * Detect special cases and adjust section sizes accordingly:
+ * 1) .init.* may be embedded into .data sections
+ * 2) .init.text.* may be out of [__init_begin, __init_end],
+ * please refer to arch/tile/kernel/vmlinux.lds.S.
+ * 3) .rodata.* may be embedded into .text or .data sections.
+ */
+#define adj_init_size(start, end, size, pos, adj) \
+ if (start <= pos && pos < end && size > adj) \
+ size -= adj;
+
+ adj_init_size(__init_begin, __init_end, init_data_size,
+ _sinittext, init_code_size);
+ adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
+ adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
+ adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
+ adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
+
+#undef adj_init_size
+
+ printk("Memory: %luK/%luK available "
+ "(%luK kernel code, %luK rwdata, %luK rodata, "
+ "%luK init, %luK bss, %luK reserved"
+#ifdef CONFIG_HIGHMEM
+ ", %luK highmem"
+#endif
+ "%s%s)\n",
+ nr_free_pages() << (PAGE_SHIFT-10), physpages << (PAGE_SHIFT-10),
+ codesize >> 10, datasize >> 10, rosize >> 10,
+ (init_data_size + init_code_size) >> 10, bss_size >> 10,
+ (physpages - totalram_pages) << (PAGE_SHIFT-10),
+#ifdef CONFIG_HIGHMEM
+ totalhigh_pages << (PAGE_SHIFT-10),
+#endif
+ str ? ", " : "", str ? str : "");
+}
+
/**
* set_dma_reserve - set the specified number of pages reserved in the first zone
* @new_dma_reserve: The number of pages to mark reserved
@@ -5454,14 +5590,21 @@
int __meminit init_per_zone_wmark_min(void)
{
unsigned long lowmem_kbytes;
+ int new_min_free_kbytes;
lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
+ new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
- min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
- if (min_free_kbytes < 128)
- min_free_kbytes = 128;
- if (min_free_kbytes > 65536)
- min_free_kbytes = 65536;
+ if (new_min_free_kbytes > user_min_free_kbytes) {
+ min_free_kbytes = new_min_free_kbytes;
+ if (min_free_kbytes < 128)
+ min_free_kbytes = 128;
+ if (min_free_kbytes > 65536)
+ min_free_kbytes = 65536;
+ } else {
+ pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
+ new_min_free_kbytes, user_min_free_kbytes);
+ }
setup_per_zone_wmarks();
refresh_zone_stat_thresholds();
setup_per_zone_lowmem_reserve();
@@ -5479,8 +5622,10 @@
void __user *buffer, size_t *length, loff_t *ppos)
{
proc_dointvec(table, write, buffer, length, ppos);
- if (write)
+ if (write) {
+ user_min_free_kbytes = min_free_kbytes;
setup_per_zone_wmarks();
+ }
return 0;
}
@@ -5540,7 +5685,6 @@
* cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
* can have before it gets flushed back to buddy allocator.
*/
-
int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
void __user *buffer, size_t *length, loff_t *ppos)
{
@@ -5551,14 +5695,16 @@
ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
if (!write || (ret < 0))
return ret;
+
+ mutex_lock(&pcp_batch_high_lock);
for_each_populated_zone(zone) {
- for_each_possible_cpu(cpu) {
- unsigned long high;
- high = zone->managed_pages / percpu_pagelist_fraction;
- setup_pagelist_highmark(
- per_cpu_ptr(zone->pageset, cpu), high);
- }
+ unsigned long high;
+ high = zone->managed_pages / percpu_pagelist_fraction;
+ for_each_possible_cpu(cpu)
+ pageset_set_high(per_cpu_ptr(zone->pageset, cpu),
+ high);
}
+ mutex_unlock(&pcp_batch_high_lock);
return 0;
}
@@ -6047,32 +6193,18 @@
#endif
#ifdef CONFIG_MEMORY_HOTPLUG
-static int __meminit __zone_pcp_update(void *data)
-{
- struct zone *zone = data;
- int cpu;
- unsigned long batch = zone_batchsize(zone), flags;
-
- for_each_possible_cpu(cpu) {
- struct per_cpu_pageset *pset;
- struct per_cpu_pages *pcp;
-
- pset = per_cpu_ptr(zone->pageset, cpu);
- pcp = &pset->pcp;
-
- local_irq_save(flags);
- if (pcp->count > 0)
- free_pcppages_bulk(zone, pcp->count, pcp);
- drain_zonestat(zone, pset);
- setup_pageset(pset, batch);
- local_irq_restore(flags);
- }
- return 0;
-}
-
+/*
+ * The zone indicated has a new number of managed_pages; batch sizes and percpu
+ * page high values need to be recalulated.
+ */
void __meminit zone_pcp_update(struct zone *zone)
{
- stop_machine(__zone_pcp_update, zone, NULL);
+ unsigned cpu;
+ mutex_lock(&pcp_batch_high_lock);
+ for_each_possible_cpu(cpu)
+ pageset_set_high_and_batch(zone,
+ per_cpu_ptr(zone->pageset, cpu));
+ mutex_unlock(&pcp_batch_high_lock);
}
#endif
@@ -6142,6 +6274,10 @@
list_del(&page->lru);
rmv_page_order(page);
zone->free_area[order].nr_free--;
+#ifdef CONFIG_HIGHMEM
+ if (PageHighMem(page))
+ totalhigh_pages -= 1 << order;
+#endif
for (i = 0; i < (1 << order); i++)
SetPageReserved((page+i));
pfn += (1 << order);
diff --git a/mm/page_io.c b/mm/page_io.c
index a8a3ef4..ba05b64 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -21,6 +21,7 @@
#include <linux/writeback.h>
#include <linux/frontswap.h>
#include <linux/aio.h>
+#include <linux/blkdev.h>
#include <asm/pgtable.h>
static struct bio *get_swap_bio(gfp_t gfp_flags,
@@ -80,9 +81,54 @@
imajor(bio->bi_bdev->bd_inode),
iminor(bio->bi_bdev->bd_inode),
(unsigned long long)bio->bi_sector);
- } else {
- SetPageUptodate(page);
+ goto out;
}
+
+ SetPageUptodate(page);
+
+ /*
+ * There is no guarantee that the page is in swap cache - the software
+ * suspend code (at least) uses end_swap_bio_read() against a non-
+ * swapcache page. So we must check PG_swapcache before proceeding with
+ * this optimization.
+ */
+ if (likely(PageSwapCache(page))) {
+ struct swap_info_struct *sis;
+
+ sis = page_swap_info(page);
+ if (sis->flags & SWP_BLKDEV) {
+ /*
+ * The swap subsystem performs lazy swap slot freeing,
+ * expecting that the page will be swapped out again.
+ * So we can avoid an unnecessary write if the page
+ * isn't redirtied.
+ * This is good for real swap storage because we can
+ * reduce unnecessary I/O and enhance wear-leveling
+ * if an SSD is used as the as swap device.
+ * But if in-memory swap device (eg zram) is used,
+ * this causes a duplicated copy between uncompressed
+ * data in VM-owned memory and compressed data in
+ * zram-owned memory. So let's free zram-owned memory
+ * and make the VM-owned decompressed page *dirty*,
+ * so the page should be swapped out somewhere again if
+ * we again wish to reclaim it.
+ */
+ struct gendisk *disk = sis->bdev->bd_disk;
+ if (disk->fops->swap_slot_free_notify) {
+ swp_entry_t entry;
+ unsigned long offset;
+
+ entry.val = page_private(page);
+ offset = swp_offset(entry);
+
+ SetPageDirty(page);
+ disk->fops->swap_slot_free_notify(sis->bdev,
+ offset);
+ }
+ }
+ }
+
+out:
unlock_page(page);
bio_put(bio);
}
diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
index 0c8323f..e1a6e4f 100644
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -124,7 +124,8 @@
#ifndef __HAVE_ARCH_PGTABLE_DEPOSIT
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable)
+void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
+ pgtable_t pgtable)
{
assert_spin_locked(&mm->page_table_lock);
@@ -141,7 +142,7 @@
#ifndef __HAVE_ARCH_PGTABLE_WITHDRAW
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
/* no "address" argument so destroys page coloring of some arch */
-pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm)
+pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
{
pgtable_t pgtable;
diff --git a/mm/rmap.c b/mm/rmap.c
index 6280da8..cd356df 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -720,7 +720,7 @@
* mapping is already gone, the unmap path will have
* set PG_referenced or activated the page.
*/
- if (likely(!VM_SequentialReadHint(vma)))
+ if (likely(!(vma->vm_flags & VM_SEQ_READ)))
referenced++;
}
pte_unmap_unlock(pte, ptl);
@@ -1093,9 +1093,10 @@
else
__inc_zone_page_state(page, NR_ANON_TRANSPARENT_HUGEPAGES);
__page_set_anon_rmap(page, vma, address, 1);
- if (!mlocked_vma_newpage(vma, page))
- lru_cache_add_lru(page, LRU_ACTIVE_ANON);
- else
+ if (!mlocked_vma_newpage(vma, page)) {
+ SetPageActive(page);
+ lru_cache_add(page);
+ } else
add_page_to_unevictable_list(page);
}
diff --git a/mm/shmem.c b/mm/shmem.c
index 118dfa4..a87990c 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1936,6 +1936,13 @@
inode = shmem_get_inode(dir->i_sb, dir, mode, dev, VM_NORESERVE);
if (inode) {
+#ifdef CONFIG_TMPFS_POSIX_ACL
+ error = generic_acl_init(inode, dir);
+ if (error) {
+ iput(inode);
+ return error;
+ }
+#endif
error = security_inode_init_security(inode, dir,
&dentry->d_name,
shmem_initxattrs, NULL);
@@ -1945,15 +1952,8 @@
return error;
}
}
-#ifdef CONFIG_TMPFS_POSIX_ACL
- error = generic_acl_init(inode, dir);
- if (error) {
- iput(inode);
- return error;
- }
-#else
+
error = 0;
-#endif
dir->i_size += BOGO_DIRENT_SIZE;
dir->i_ctime = dir->i_mtime = CURRENT_TIME;
d_instantiate(dentry, inode);
diff --git a/mm/slab.c b/mm/slab.c
index 8ccd296..35cb0c8 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -565,7 +565,7 @@
if (slab_state < UP)
return;
- for (i = 1; i < PAGE_SHIFT + MAX_ORDER; i++) {
+ for (i = 1; i <= KMALLOC_SHIFT_HIGH; i++) {
struct kmem_cache_node *n;
struct kmem_cache *cache = kmalloc_caches[i];
@@ -1180,6 +1180,12 @@
return 0;
}
+static inline int slabs_tofree(struct kmem_cache *cachep,
+ struct kmem_cache_node *n)
+{
+ return (n->free_objects + cachep->num - 1) / cachep->num;
+}
+
static void __cpuinit cpuup_canceled(long cpu)
{
struct kmem_cache *cachep;
@@ -1241,7 +1247,7 @@
n = cachep->node[node];
if (!n)
continue;
- drain_freelist(cachep, n, n->free_objects);
+ drain_freelist(cachep, n, slabs_tofree(cachep, n));
}
}
@@ -1408,7 +1414,7 @@
if (!n)
continue;
- drain_freelist(cachep, n, n->free_objects);
+ drain_freelist(cachep, n, slabs_tofree(cachep, n));
if (!list_empty(&n->slabs_full) ||
!list_empty(&n->slabs_partial)) {
@@ -2532,7 +2538,7 @@
if (!n)
continue;
- drain_freelist(cachep, n, n->free_objects);
+ drain_freelist(cachep, n, slabs_tofree(cachep, n));
ret += !list_empty(&n->slabs_full) ||
!list_empty(&n->slabs_partial);
@@ -3338,18 +3344,6 @@
return obj;
}
-/**
- * kmem_cache_alloc_node - Allocate an object on the specified node
- * @cachep: The cache to allocate from.
- * @flags: See kmalloc().
- * @nodeid: node number of the target node.
- * @caller: return address of caller, used for debug information
- *
- * Identical to kmem_cache_alloc but it will allocate memory on the given
- * node, which can improve the performance for cpu bound structures.
- *
- * Fallback to other node is possible if __GFP_THISNODE is not set.
- */
static __always_inline void *
slab_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid,
unsigned long caller)
@@ -3643,6 +3637,17 @@
#endif
#ifdef CONFIG_NUMA
+/**
+ * kmem_cache_alloc_node - Allocate an object on the specified node
+ * @cachep: The cache to allocate from.
+ * @flags: See kmalloc().
+ * @nodeid: node number of the target node.
+ *
+ * Identical to kmem_cache_alloc but it will allocate memory on the given
+ * node, which can improve the performance for cpu bound structures.
+ *
+ * Fallback to other node is possible if __GFP_THISNODE is not set.
+ */
void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
{
void *ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_);
@@ -4431,20 +4436,10 @@
return 0;
}
-static void *s_next(struct seq_file *m, void *p, loff_t *pos)
-{
- return seq_list_next(p, &slab_caches, pos);
-}
-
-static void s_stop(struct seq_file *m, void *p)
-{
- mutex_unlock(&slab_mutex);
-}
-
static const struct seq_operations slabstats_op = {
.start = leaks_start,
- .next = s_next,
- .stop = s_stop,
+ .next = slab_next,
+ .stop = slab_stop,
.show = leaks_show,
};
diff --git a/mm/slab.h b/mm/slab.h
index f96b49e..620ceed 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -271,3 +271,6 @@
#endif
};
+
+void *slab_next(struct seq_file *m, void *p, loff_t *pos);
+void slab_stop(struct seq_file *m, void *p);
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 2d41450..538bade 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -497,6 +497,13 @@
#ifdef CONFIG_SLABINFO
+
+#ifdef CONFIG_SLAB
+#define SLABINFO_RIGHTS (S_IWUSR | S_IRUSR)
+#else
+#define SLABINFO_RIGHTS S_IRUSR
+#endif
+
void print_slabinfo_header(struct seq_file *m)
{
/*
@@ -531,12 +538,12 @@
return seq_list_start(&slab_caches, *pos);
}
-static void *s_next(struct seq_file *m, void *p, loff_t *pos)
+void *slab_next(struct seq_file *m, void *p, loff_t *pos)
{
return seq_list_next(p, &slab_caches, pos);
}
-static void s_stop(struct seq_file *m, void *p)
+void slab_stop(struct seq_file *m, void *p)
{
mutex_unlock(&slab_mutex);
}
@@ -613,8 +620,8 @@
*/
static const struct seq_operations slabinfo_op = {
.start = s_start,
- .next = s_next,
- .stop = s_stop,
+ .next = slab_next,
+ .stop = slab_stop,
.show = s_show,
};
@@ -633,7 +640,8 @@
static int __init slab_proc_init(void)
{
- proc_create("slabinfo", S_IRUSR, NULL, &proc_slabinfo_operations);
+ proc_create("slabinfo", SLABINFO_RIGHTS, NULL,
+ &proc_slabinfo_operations);
return 0;
}
module_init(slab_proc_init);
diff --git a/mm/slob.c b/mm/slob.c
index eeed4a0..91bd3f2 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -122,7 +122,7 @@
}
#define SLOB_UNIT sizeof(slob_t)
-#define SLOB_UNITS(size) (((size) + SLOB_UNIT - 1)/SLOB_UNIT)
+#define SLOB_UNITS(size) DIV_ROUND_UP(size, SLOB_UNIT)
/*
* struct slob_rcu is inserted at the tail of allocated slob blocks, which
@@ -554,7 +554,7 @@
flags, node);
}
- if (c->ctor)
+ if (b && c->ctor)
c->ctor(b);
kmemleak_alloc_recursive(b, c->size, 1, c->flags, flags);
diff --git a/mm/slub.c b/mm/slub.c
index 57707f0..3b482c8 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -123,6 +123,15 @@
#endif
}
+static inline bool kmem_cache_has_cpu_partial(struct kmem_cache *s)
+{
+#ifdef CONFIG_SLUB_CPU_PARTIAL
+ return !kmem_cache_debug(s);
+#else
+ return false;
+#endif
+}
+
/*
* Issues still to be resolved:
*
@@ -1573,7 +1582,8 @@
put_cpu_partial(s, page, 0);
stat(s, CPU_PARTIAL_NODE);
}
- if (kmem_cache_debug(s) || available > s->cpu_partial / 2)
+ if (!kmem_cache_has_cpu_partial(s)
+ || available > s->cpu_partial / 2)
break;
}
@@ -1884,6 +1894,7 @@
static void unfreeze_partials(struct kmem_cache *s,
struct kmem_cache_cpu *c)
{
+#ifdef CONFIG_SLUB_CPU_PARTIAL
struct kmem_cache_node *n = NULL, *n2 = NULL;
struct page *page, *discard_page = NULL;
@@ -1938,6 +1949,7 @@
discard_slab(s, page);
stat(s, FREE_SLAB);
}
+#endif
}
/*
@@ -1951,10 +1963,14 @@
*/
static void put_cpu_partial(struct kmem_cache *s, struct page *page, int drain)
{
+#ifdef CONFIG_SLUB_CPU_PARTIAL
struct page *oldpage;
int pages;
int pobjects;
+ if (!s->cpu_partial)
+ return;
+
do {
pages = 0;
pobjects = 0;
@@ -1987,6 +2003,7 @@
page->next = oldpage;
} while (this_cpu_cmpxchg(s->cpu_slab->partial, oldpage, page) != oldpage);
+#endif
}
static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
@@ -2358,7 +2375,7 @@
object = c->freelist;
page = c->page;
- if (unlikely(!object || !node_match(page, node)))
+ if (unlikely(!object || !page || !node_match(page, node)))
object = __slab_alloc(s, gfpflags, node, addr, c);
else {
@@ -2495,7 +2512,7 @@
new.inuse--;
if ((!new.inuse || !prior) && !was_frozen) {
- if (!kmem_cache_debug(s) && !prior)
+ if (kmem_cache_has_cpu_partial(s) && !prior)
/*
* Slab was on no list before and will be partially empty
@@ -2550,8 +2567,9 @@
* Objects left in the slab. If it was not on the partial list before
* then add it.
*/
- if (kmem_cache_debug(s) && unlikely(!prior)) {
- remove_full(s, page);
+ if (!kmem_cache_has_cpu_partial(s) && unlikely(!prior)) {
+ if (kmem_cache_debug(s))
+ remove_full(s, page);
add_partial(n, page, DEACTIVATE_TO_TAIL);
stat(s, FREE_ADD_PARTIAL);
}
@@ -3059,7 +3077,7 @@
* per node list when we run out of per cpu objects. We only fetch 50%
* to keep some capacity around for frees.
*/
- if (kmem_cache_debug(s))
+ if (!kmem_cache_has_cpu_partial(s))
s->cpu_partial = 0;
else if (s->size >= PAGE_SIZE)
s->cpu_partial = 2;
@@ -4456,7 +4474,7 @@
err = strict_strtoul(buf, 10, &objects);
if (err)
return err;
- if (objects && kmem_cache_debug(s))
+ if (objects && !kmem_cache_has_cpu_partial(s))
return -EINVAL;
s->cpu_partial = objects;
@@ -5269,7 +5287,6 @@
#ifdef CONFIG_SLABINFO
void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo)
{
- unsigned long nr_partials = 0;
unsigned long nr_slabs = 0;
unsigned long nr_objs = 0;
unsigned long nr_free = 0;
@@ -5281,9 +5298,8 @@
if (!n)
continue;
- nr_partials += n->nr_partial;
- nr_slabs += atomic_long_read(&n->nr_slabs);
- nr_objs += atomic_long_read(&n->total_objects);
+ nr_slabs += node_nr_slabs(n);
+ nr_objs += node_nr_objs(n);
nr_free += count_partial(n, count_free);
}
diff --git a/mm/sparse.c b/mm/sparse.c
index 1c91f0d3..308d5033 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -79,7 +79,6 @@
{
unsigned long root = SECTION_NR_TO_ROOT(section_nr);
struct mem_section *section;
- int ret = 0;
if (mem_section[root])
return -EEXIST;
@@ -90,7 +89,7 @@
mem_section[root] = section;
- return ret;
+ return 0;
}
#else /* !SPARSEMEM_EXTREME */
static inline int sparse_index_init(unsigned long section_nr, int nid)
@@ -481,6 +480,9 @@
struct page **map_map;
#endif
+ /* see include/linux/mmzone.h 'struct mem_section' definition */
+ BUILD_BUG_ON(!is_power_of_2(sizeof(struct mem_section)));
+
/* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */
set_pageblock_order();
@@ -751,6 +753,7 @@
return ret;
}
+#ifdef CONFIG_MEMORY_HOTREMOVE
#ifdef CONFIG_MEMORY_FAILURE
static void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
{
@@ -772,7 +775,6 @@
}
#endif
-#ifdef CONFIG_MEMORY_HOTREMOVE
static void free_section_usemap(struct page *memmap, unsigned long *usemap)
{
struct page *usemap_page;
diff --git a/mm/swap.c b/mm/swap.c
index dfd7d71..4a1d0d2 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -34,10 +34,13 @@
#include "internal.h"
+#define CREATE_TRACE_POINTS
+#include <trace/events/pagemap.h>
+
/* How many pages do we try to swap or page in/out together? */
int page_cluster;
-static DEFINE_PER_CPU(struct pagevec[NR_LRU_LISTS], lru_add_pvecs);
+static DEFINE_PER_CPU(struct pagevec, lru_add_pvec);
static DEFINE_PER_CPU(struct pagevec, lru_rotate_pvecs);
static DEFINE_PER_CPU(struct pagevec, lru_deactivate_pvecs);
@@ -384,6 +387,7 @@
SetPageActive(page);
lru += LRU_ACTIVE;
add_page_to_lru_list(page, lruvec, lru);
+ trace_mm_lru_activate(page, page_to_pfn(page));
__count_vm_event(PGACTIVATE);
update_page_reclaim_stat(lruvec, file, 1);
@@ -428,6 +432,33 @@
}
#endif
+static void __lru_cache_activate_page(struct page *page)
+{
+ struct pagevec *pvec = &get_cpu_var(lru_add_pvec);
+ int i;
+
+ /*
+ * Search backwards on the optimistic assumption that the page being
+ * activated has just been added to this pagevec. Note that only
+ * the local pagevec is examined as a !PageLRU page could be in the
+ * process of being released, reclaimed, migrated or on a remote
+ * pagevec that is currently being drained. Furthermore, marking
+ * a remote pagevec's page PageActive potentially hits a race where
+ * a page is marked PageActive just after it is added to the inactive
+ * list causing accounting errors and BUG_ON checks to trigger.
+ */
+ for (i = pagevec_count(pvec) - 1; i >= 0; i--) {
+ struct page *pagevec_page = pvec->pages[i];
+
+ if (pagevec_page == page) {
+ SetPageActive(page);
+ break;
+ }
+ }
+
+ put_cpu_var(lru_add_pvec);
+}
+
/*
* Mark a page as having seen activity.
*
@@ -438,8 +469,18 @@
void mark_page_accessed(struct page *page)
{
if (!PageActive(page) && !PageUnevictable(page) &&
- PageReferenced(page) && PageLRU(page)) {
- activate_page(page);
+ PageReferenced(page)) {
+
+ /*
+ * If the page is on the LRU, queue it for activation via
+ * activate_page_pvecs. Otherwise, assume the page is on a
+ * pagevec, mark it active and it'll be moved to the active
+ * LRU on the next drain.
+ */
+ if (PageLRU(page))
+ activate_page(page);
+ else
+ __lru_cache_activate_page(page);
ClearPageReferenced(page);
} else if (!PageReferenced(page)) {
SetPageReferenced(page);
@@ -448,42 +489,37 @@
EXPORT_SYMBOL(mark_page_accessed);
/*
- * Order of operations is important: flush the pagevec when it's already
- * full, not when adding the last page, to make sure that last page is
- * not added to the LRU directly when passed to this function. Because
- * mark_page_accessed() (called after this when writing) only activates
- * pages that are on the LRU, linear writes in subpage chunks would see
- * every PAGEVEC_SIZE page activated, which is unexpected.
+ * Queue the page for addition to the LRU via pagevec. The decision on whether
+ * to add the page to the [in]active [file|anon] list is deferred until the
+ * pagevec is drained. This gives a chance for the caller of __lru_cache_add()
+ * have the page added to the active list using mark_page_accessed().
*/
-void __lru_cache_add(struct page *page, enum lru_list lru)
+void __lru_cache_add(struct page *page)
{
- struct pagevec *pvec = &get_cpu_var(lru_add_pvecs)[lru];
+ struct pagevec *pvec = &get_cpu_var(lru_add_pvec);
page_cache_get(page);
if (!pagevec_space(pvec))
- __pagevec_lru_add(pvec, lru);
+ __pagevec_lru_add(pvec);
pagevec_add(pvec, page);
- put_cpu_var(lru_add_pvecs);
+ put_cpu_var(lru_add_pvec);
}
EXPORT_SYMBOL(__lru_cache_add);
/**
- * lru_cache_add_lru - add a page to a page list
+ * lru_cache_add - add a page to a page list
* @page: the page to be added to the LRU.
- * @lru: the LRU list to which the page is added.
*/
-void lru_cache_add_lru(struct page *page, enum lru_list lru)
+void lru_cache_add(struct page *page)
{
if (PageActive(page)) {
VM_BUG_ON(PageUnevictable(page));
- ClearPageActive(page);
} else if (PageUnevictable(page)) {
VM_BUG_ON(PageActive(page));
- ClearPageUnevictable(page);
}
- VM_BUG_ON(PageLRU(page) || PageActive(page) || PageUnevictable(page));
- __lru_cache_add(page, lru);
+ VM_BUG_ON(PageLRU(page));
+ __lru_cache_add(page);
}
/**
@@ -583,15 +619,10 @@
*/
void lru_add_drain_cpu(int cpu)
{
- struct pagevec *pvecs = per_cpu(lru_add_pvecs, cpu);
- struct pagevec *pvec;
- int lru;
+ struct pagevec *pvec = &per_cpu(lru_add_pvec, cpu);
- for_each_lru(lru) {
- pvec = &pvecs[lru - LRU_BASE];
- if (pagevec_count(pvec))
- __pagevec_lru_add(pvec, lru);
- }
+ if (pagevec_count(pvec))
+ __pagevec_lru_add(pvec);
pvec = &per_cpu(lru_rotate_pvecs, cpu);
if (pagevec_count(pvec)) {
@@ -708,6 +739,9 @@
del_page_from_lru_list(page, lruvec, page_off_lru(page));
}
+ /* Clear Active bit in case of parallel mark_page_accessed */
+ ClearPageActive(page);
+
list_add(&page->lru, &pages_to_free);
}
if (zone)
@@ -795,30 +829,26 @@
static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec,
void *arg)
{
- enum lru_list lru = (enum lru_list)arg;
- int file = is_file_lru(lru);
- int active = is_active_lru(lru);
+ int file = page_is_file_cache(page);
+ int active = PageActive(page);
+ enum lru_list lru = page_lru(page);
- VM_BUG_ON(PageActive(page));
VM_BUG_ON(PageUnevictable(page));
VM_BUG_ON(PageLRU(page));
SetPageLRU(page);
- if (active)
- SetPageActive(page);
add_page_to_lru_list(page, lruvec, lru);
update_page_reclaim_stat(lruvec, file, active);
+ trace_mm_lru_insertion(page, page_to_pfn(page), lru, trace_pagemap_flags(page));
}
/*
* Add the passed pages to the LRU, then drop the caller's refcount
* on them. Reinitialises the caller's pagevec.
*/
-void __pagevec_lru_add(struct pagevec *pvec, enum lru_list lru)
+void __pagevec_lru_add(struct pagevec *pvec)
{
- VM_BUG_ON(is_unevictable_lru(lru));
-
- pagevec_lru_move_fn(pvec, __pagevec_lru_add_fn, (void *)lru);
+ pagevec_lru_move_fn(pvec, __pagevec_lru_add_fn, NULL);
}
EXPORT_SYMBOL(__pagevec_lru_add);
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 746af55b..36af6ee 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -212,7 +212,7 @@
si->cluster_nr = SWAPFILE_CLUSTER - 1;
goto checks;
}
- if (si->flags & SWP_DISCARDABLE) {
+ if (si->flags & SWP_PAGE_DISCARD) {
/*
* Start range check on racing allocations, in case
* they overlap the cluster we eventually decide on
@@ -322,7 +322,7 @@
if (si->lowest_alloc) {
/*
- * Only set when SWP_DISCARDABLE, and there's a scan
+ * Only set when SWP_PAGE_DISCARD, and there's a scan
* for a free cluster in progress or just completed.
*/
if (found_free_cluster) {
@@ -2016,6 +2016,20 @@
return nr_extents;
}
+/*
+ * Helper to sys_swapon determining if a given swap
+ * backing device queue supports DISCARD operations.
+ */
+static bool swap_discardable(struct swap_info_struct *si)
+{
+ struct request_queue *q = bdev_get_queue(si->bdev);
+
+ if (!q || !blk_queue_discard(q))
+ return false;
+
+ return true;
+}
+
SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
{
struct swap_info_struct *p;
@@ -2123,8 +2137,37 @@
p->flags |= SWP_SOLIDSTATE;
p->cluster_next = 1 + (prandom_u32() % p->highest_bit);
}
- if ((swap_flags & SWAP_FLAG_DISCARD) && discard_swap(p) == 0)
- p->flags |= SWP_DISCARDABLE;
+
+ if ((swap_flags & SWAP_FLAG_DISCARD) && swap_discardable(p)) {
+ /*
+ * When discard is enabled for swap with no particular
+ * policy flagged, we set all swap discard flags here in
+ * order to sustain backward compatibility with older
+ * swapon(8) releases.
+ */
+ p->flags |= (SWP_DISCARDABLE | SWP_AREA_DISCARD |
+ SWP_PAGE_DISCARD);
+
+ /*
+ * By flagging sys_swapon, a sysadmin can tell us to
+ * either do single-time area discards only, or to just
+ * perform discards for released swap page-clusters.
+ * Now it's time to adjust the p->flags accordingly.
+ */
+ if (swap_flags & SWAP_FLAG_DISCARD_ONCE)
+ p->flags &= ~SWP_PAGE_DISCARD;
+ else if (swap_flags & SWAP_FLAG_DISCARD_PAGES)
+ p->flags &= ~SWP_AREA_DISCARD;
+
+ /* issue a swapon-time discard if it's still required */
+ if (p->flags & SWP_AREA_DISCARD) {
+ int err = discard_swap(p);
+ if (unlikely(err))
+ printk(KERN_ERR
+ "swapon: discard_swap(%p): %d\n",
+ p, err);
+ }
+ }
}
mutex_lock(&swapon_mutex);
@@ -2135,11 +2178,13 @@
enable_swap_info(p, prio, swap_map, frontswap_map);
printk(KERN_INFO "Adding %uk swap on %s. "
- "Priority:%d extents:%d across:%lluk %s%s%s\n",
+ "Priority:%d extents:%d across:%lluk %s%s%s%s%s\n",
p->pages<<(PAGE_SHIFT-10), name->name, p->prio,
nr_extents, (unsigned long long)span<<(PAGE_SHIFT-10),
(p->flags & SWP_SOLIDSTATE) ? "SS" : "",
(p->flags & SWP_DISCARDABLE) ? "D" : "",
+ (p->flags & SWP_AREA_DISCARD) ? "s" : "",
+ (p->flags & SWP_PAGE_DISCARD) ? "c" : "",
(frontswap_map) ? "FS" : "");
mutex_unlock(&swapon_mutex);
diff --git a/mm/util.c b/mm/util.c
index ab1424d..7441c41 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -295,7 +295,6 @@
{
mm->mmap_base = TASK_UNMAPPED_BASE;
mm->get_unmapped_area = arch_get_unmapped_area;
- mm->unmap_area = arch_unmap_area;
}
#endif
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index d365724..13a5495 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -292,7 +292,7 @@
va = rb_entry(n, struct vmap_area, rb_node);
if (addr < va->va_start)
n = n->rb_left;
- else if (addr > va->va_start)
+ else if (addr >= va->va_end)
n = n->rb_right;
else
return va;
@@ -388,12 +388,12 @@
addr = ALIGN(first->va_end, align);
if (addr < vstart)
goto nocache;
- if (addr + size - 1 < addr)
+ if (addr + size < addr)
goto overflow;
} else {
addr = ALIGN(vstart, align);
- if (addr + size - 1 < addr)
+ if (addr + size < addr)
goto overflow;
n = vmap_area_root.rb_node;
@@ -420,7 +420,7 @@
if (addr + cached_hole_size < first->va_start)
cached_hole_size = first->va_start - addr;
addr = ALIGN(first->va_end, align);
- if (addr + size - 1 < addr)
+ if (addr + size < addr)
goto overflow;
if (list_is_last(&first->list, &vmap_area_list))
@@ -754,7 +754,6 @@
struct vmap_area *va;
struct vmap_block_queue *vbq;
unsigned long free, dirty;
- DECLARE_BITMAP(alloc_map, VMAP_BBMAP_BITS);
DECLARE_BITMAP(dirty_map, VMAP_BBMAP_BITS);
struct list_head free_list;
struct rcu_head rcu_head;
@@ -820,7 +819,6 @@
vb->va = va;
vb->free = VMAP_BBMAP_BITS;
vb->dirty = 0;
- bitmap_zero(vb->alloc_map, VMAP_BBMAP_BITS);
bitmap_zero(vb->dirty_map, VMAP_BBMAP_BITS);
INIT_LIST_HEAD(&vb->free_list);
@@ -873,7 +871,6 @@
if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
vb->free = 0; /* prevent further allocs after releasing lock */
vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
- bitmap_fill(vb->alloc_map, VMAP_BBMAP_BITS);
bitmap_fill(vb->dirty_map, VMAP_BBMAP_BITS);
spin_lock(&vbq->lock);
list_del_rcu(&vb->free_list);
@@ -891,11 +888,6 @@
}
}
-static void purge_fragmented_blocks_thiscpu(void)
-{
- purge_fragmented_blocks(smp_processor_id());
-}
-
static void purge_fragmented_blocks_allcpus(void)
{
int cpu;
@@ -910,7 +902,6 @@
struct vmap_block *vb;
unsigned long addr = 0;
unsigned int order;
- int purge = 0;
BUG_ON(size & ~PAGE_MASK);
BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
@@ -934,17 +925,7 @@
if (vb->free < 1UL << order)
goto next;
- i = bitmap_find_free_region(vb->alloc_map,
- VMAP_BBMAP_BITS, order);
-
- if (i < 0) {
- if (vb->free + vb->dirty == VMAP_BBMAP_BITS) {
- /* fragmented and no outstanding allocations */
- BUG_ON(vb->dirty != VMAP_BBMAP_BITS);
- purge = 1;
- }
- goto next;
- }
+ i = VMAP_BBMAP_BITS - vb->free;
addr = vb->va->va_start + (i << PAGE_SHIFT);
BUG_ON(addr_to_vb_idx(addr) !=
addr_to_vb_idx(vb->va->va_start));
@@ -960,9 +941,6 @@
spin_unlock(&vb->lock);
}
- if (purge)
- purge_fragmented_blocks_thiscpu();
-
put_cpu_var(vmap_block_queue);
rcu_read_unlock();
@@ -1311,22 +1289,15 @@
spin_unlock(&vmap_area_lock);
}
-static void clear_vm_unlist(struct vm_struct *vm)
+static void clear_vm_uninitialized_flag(struct vm_struct *vm)
{
/*
- * Before removing VM_UNLIST,
+ * Before removing VM_UNINITIALIZED,
* we should make sure that vm has proper values.
* Pair with smp_rmb() in show_numa_info().
*/
smp_wmb();
- vm->flags &= ~VM_UNLIST;
-}
-
-static void insert_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
- unsigned long flags, const void *caller)
-{
- setup_vmalloc_vm(vm, va, flags, caller);
- clear_vm_unlist(vm);
+ vm->flags &= ~VM_UNINITIALIZED;
}
static struct vm_struct *__get_vm_area_node(unsigned long size,
@@ -1337,16 +1308,8 @@
struct vm_struct *area;
BUG_ON(in_interrupt());
- if (flags & VM_IOREMAP) {
- int bit = fls(size);
-
- if (bit > IOREMAP_MAX_ORDER)
- bit = IOREMAP_MAX_ORDER;
- else if (bit < PAGE_SHIFT)
- bit = PAGE_SHIFT;
-
- align = 1ul << bit;
- }
+ if (flags & VM_IOREMAP)
+ align = 1ul << clamp(fls(size), PAGE_SHIFT, IOREMAP_MAX_ORDER);
size = PAGE_ALIGN(size);
if (unlikely(!size))
@@ -1367,16 +1330,7 @@
return NULL;
}
- /*
- * When this function is called from __vmalloc_node_range,
- * we add VM_UNLIST flag to avoid accessing uninitialized
- * members of vm_struct such as pages and nr_pages fields.
- * They will be set later.
- */
- if (flags & VM_UNLIST)
- setup_vmalloc_vm(area, va, flags, caller);
- else
- insert_vmalloc_vm(area, va, flags, caller);
+ setup_vmalloc_vm(area, va, flags, caller);
return area;
}
@@ -1476,10 +1430,9 @@
if (!addr)
return;
- if ((PAGE_SIZE-1) & (unsigned long)addr) {
- WARN(1, KERN_ERR "Trying to vfree() bad address (%p)\n", addr);
+ if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n",
+ addr))
return;
- }
area = remove_vm_area(addr);
if (unlikely(!area)) {
@@ -1524,7 +1477,6 @@
* conventions for vfree() arch-depenedent would be a really bad idea)
*
* NOTE: assumes that the object at *addr has a size >= sizeof(llist_node)
- *
*/
void vfree(const void *addr)
{
@@ -1536,8 +1488,8 @@
return;
if (unlikely(in_interrupt())) {
struct vfree_deferred *p = &__get_cpu_var(vfree_deferred);
- llist_add((struct llist_node *)addr, &p->list);
- schedule_work(&p->wq);
+ if (llist_add((struct llist_node *)addr, &p->list))
+ schedule_work(&p->wq);
} else
__vunmap(addr, 1);
}
@@ -1682,21 +1634,21 @@
if (!size || (size >> PAGE_SHIFT) > totalram_pages)
goto fail;
- area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNLIST,
+ area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNINITIALIZED,
start, end, node, gfp_mask, caller);
if (!area)
goto fail;
addr = __vmalloc_area_node(area, gfp_mask, prot, node, caller);
if (!addr)
- return NULL;
+ goto fail;
/*
- * In this function, newly allocated vm_struct has VM_UNLIST flag.
- * It means that vm_struct is not fully initialized.
+ * In this function, newly allocated vm_struct has VM_UNINITIALIZED
+ * flag. It means that vm_struct is not fully initialized.
* Now, it is fully initialized, so remove this flag here.
*/
- clear_vm_unlist(area);
+ clear_vm_uninitialized_flag(area);
/*
* A ref_count = 3 is needed because the vm_struct and vmap_area
@@ -2148,6 +2100,61 @@
}
/**
+ * remap_vmalloc_range_partial - map vmalloc pages to userspace
+ * @vma: vma to cover
+ * @uaddr: target user address to start at
+ * @kaddr: virtual address of vmalloc kernel memory
+ * @size: size of map area
+ *
+ * Returns: 0 for success, -Exxx on failure
+ *
+ * This function checks that @kaddr is a valid vmalloc'ed area,
+ * and that it is big enough to cover the range starting at
+ * @uaddr in @vma. Will return failure if that criteria isn't
+ * met.
+ *
+ * Similar to remap_pfn_range() (see mm/memory.c)
+ */
+int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr,
+ void *kaddr, unsigned long size)
+{
+ struct vm_struct *area;
+
+ size = PAGE_ALIGN(size);
+
+ if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr))
+ return -EINVAL;
+
+ area = find_vm_area(kaddr);
+ if (!area)
+ return -EINVAL;
+
+ if (!(area->flags & VM_USERMAP))
+ return -EINVAL;
+
+ if (kaddr + size > area->addr + area->size)
+ return -EINVAL;
+
+ do {
+ struct page *page = vmalloc_to_page(kaddr);
+ int ret;
+
+ ret = vm_insert_page(vma, uaddr, page);
+ if (ret)
+ return ret;
+
+ uaddr += PAGE_SIZE;
+ kaddr += PAGE_SIZE;
+ size -= PAGE_SIZE;
+ } while (size > 0);
+
+ vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
+
+ return 0;
+}
+EXPORT_SYMBOL(remap_vmalloc_range_partial);
+
+/**
* remap_vmalloc_range - map vmalloc pages to userspace
* @vma: vma to cover (map full range of vma)
* @addr: vmalloc memory
@@ -2164,40 +2171,9 @@
int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
unsigned long pgoff)
{
- struct vm_struct *area;
- unsigned long uaddr = vma->vm_start;
- unsigned long usize = vma->vm_end - vma->vm_start;
-
- if ((PAGE_SIZE-1) & (unsigned long)addr)
- return -EINVAL;
-
- area = find_vm_area(addr);
- if (!area)
- return -EINVAL;
-
- if (!(area->flags & VM_USERMAP))
- return -EINVAL;
-
- if (usize + (pgoff << PAGE_SHIFT) > area->size - PAGE_SIZE)
- return -EINVAL;
-
- addr += pgoff << PAGE_SHIFT;
- do {
- struct page *page = vmalloc_to_page(addr);
- int ret;
-
- ret = vm_insert_page(vma, uaddr, page);
- if (ret)
- return ret;
-
- uaddr += PAGE_SIZE;
- addr += PAGE_SIZE;
- usize -= PAGE_SIZE;
- } while (usize > 0);
-
- vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
-
- return 0;
+ return remap_vmalloc_range_partial(vma, vma->vm_start,
+ addr + (pgoff << PAGE_SHIFT),
+ vma->vm_end - vma->vm_start);
}
EXPORT_SYMBOL(remap_vmalloc_range);
@@ -2512,8 +2488,8 @@
/* insert all vm's */
for (area = 0; area < nr_vms; area++)
- insert_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
- pcpu_get_vm_areas);
+ setup_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
+ pcpu_get_vm_areas);
kfree(vas);
return vms;
@@ -2592,11 +2568,6 @@
if (!counters)
return;
- /* Pair with smp_wmb() in clear_vm_unlist() */
- smp_rmb();
- if (v->flags & VM_UNLIST)
- return;
-
memset(counters, 0, nr_node_ids * sizeof(unsigned int));
for (nr = 0; nr < v->nr_pages; nr++)
@@ -2625,6 +2596,11 @@
v = va->vm;
+ /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
+ smp_rmb();
+ if (v->flags & VM_UNINITIALIZED)
+ return 0;
+
seq_printf(m, "0x%pK-0x%pK %7ld",
v->addr, v->addr + v->size, v->size);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index fa6a853..2cff0d4 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -546,7 +546,6 @@
void putback_lru_page(struct page *page)
{
int lru;
- int active = !!TestClearPageActive(page);
int was_unevictable = PageUnevictable(page);
VM_BUG_ON(PageLRU(page));
@@ -561,8 +560,8 @@
* unevictable page on [in]active list.
* We know how to handle that.
*/
- lru = active + page_lru_base_type(page);
- lru_cache_add_lru(page, lru);
+ lru = page_lru_base_type(page);
+ lru_cache_add(page);
} else {
/*
* Put unevictable pages directly on zone's unevictable
@@ -669,6 +668,35 @@
return PAGEREF_RECLAIM;
}
+/* Check if a page is dirty or under writeback */
+static void page_check_dirty_writeback(struct page *page,
+ bool *dirty, bool *writeback)
+{
+ struct address_space *mapping;
+
+ /*
+ * Anonymous pages are not handled by flushers and must be written
+ * from reclaim context. Do not stall reclaim based on them
+ */
+ if (!page_is_file_cache(page)) {
+ *dirty = false;
+ *writeback = false;
+ return;
+ }
+
+ /* By default assume that the page flags are accurate */
+ *dirty = PageDirty(page);
+ *writeback = PageWriteback(page);
+
+ /* Verify dirty/writeback state if the filesystem supports it */
+ if (!page_has_private(page))
+ return;
+
+ mapping = page_mapping(page);
+ if (mapping && mapping->a_ops->is_dirty_writeback)
+ mapping->a_ops->is_dirty_writeback(page, dirty, writeback);
+}
+
/*
* shrink_page_list() returns the number of reclaimed pages
*/
@@ -677,16 +705,21 @@
struct scan_control *sc,
enum ttu_flags ttu_flags,
unsigned long *ret_nr_dirty,
+ unsigned long *ret_nr_unqueued_dirty,
+ unsigned long *ret_nr_congested,
unsigned long *ret_nr_writeback,
+ unsigned long *ret_nr_immediate,
bool force_reclaim)
{
LIST_HEAD(ret_pages);
LIST_HEAD(free_pages);
int pgactivate = 0;
+ unsigned long nr_unqueued_dirty = 0;
unsigned long nr_dirty = 0;
unsigned long nr_congested = 0;
unsigned long nr_reclaimed = 0;
unsigned long nr_writeback = 0;
+ unsigned long nr_immediate = 0;
cond_resched();
@@ -696,6 +729,7 @@
struct page *page;
int may_enter_fs;
enum page_references references = PAGEREF_RECLAIM_CLEAN;
+ bool dirty, writeback;
cond_resched();
@@ -723,25 +757,77 @@
may_enter_fs = (sc->gfp_mask & __GFP_FS) ||
(PageSwapCache(page) && (sc->gfp_mask & __GFP_IO));
+ /*
+ * The number of dirty pages determines if a zone is marked
+ * reclaim_congested which affects wait_iff_congested. kswapd
+ * will stall and start writing pages if the tail of the LRU
+ * is all dirty unqueued pages.
+ */
+ page_check_dirty_writeback(page, &dirty, &writeback);
+ if (dirty || writeback)
+ nr_dirty++;
+
+ if (dirty && !writeback)
+ nr_unqueued_dirty++;
+
+ /*
+ * Treat this page as congested if the underlying BDI is or if
+ * pages are cycling through the LRU so quickly that the
+ * pages marked for immediate reclaim are making it to the
+ * end of the LRU a second time.
+ */
+ mapping = page_mapping(page);
+ if ((mapping && bdi_write_congested(mapping->backing_dev_info)) ||
+ (writeback && PageReclaim(page)))
+ nr_congested++;
+
+ /*
+ * If a page at the tail of the LRU is under writeback, there
+ * are three cases to consider.
+ *
+ * 1) If reclaim is encountering an excessive number of pages
+ * under writeback and this page is both under writeback and
+ * PageReclaim then it indicates that pages are being queued
+ * for IO but are being recycled through the LRU before the
+ * IO can complete. Waiting on the page itself risks an
+ * indefinite stall if it is impossible to writeback the
+ * page due to IO error or disconnected storage so instead
+ * note that the LRU is being scanned too quickly and the
+ * caller can stall after page list has been processed.
+ *
+ * 2) Global reclaim encounters a page, memcg encounters a
+ * page that is not marked for immediate reclaim or
+ * the caller does not have __GFP_IO. In this case mark
+ * the page for immediate reclaim and continue scanning.
+ *
+ * __GFP_IO is checked because a loop driver thread might
+ * enter reclaim, and deadlock if it waits on a page for
+ * which it is needed to do the write (loop masks off
+ * __GFP_IO|__GFP_FS for this reason); but more thought
+ * would probably show more reasons.
+ *
+ * Don't require __GFP_FS, since we're not going into the
+ * FS, just waiting on its writeback completion. Worryingly,
+ * ext4 gfs2 and xfs allocate pages with
+ * grab_cache_page_write_begin(,,AOP_FLAG_NOFS), so testing
+ * may_enter_fs here is liable to OOM on them.
+ *
+ * 3) memcg encounters a page that is not already marked
+ * PageReclaim. memcg does not have any dirty pages
+ * throttling so we could easily OOM just because too many
+ * pages are in writeback and there is nothing else to
+ * reclaim. Wait for the writeback to complete.
+ */
if (PageWriteback(page)) {
- /*
- * memcg doesn't have any dirty pages throttling so we
- * could easily OOM just because too many pages are in
- * writeback and there is nothing else to reclaim.
- *
- * Check __GFP_IO, certainly because a loop driver
- * thread might enter reclaim, and deadlock if it waits
- * on a page for which it is needed to do the write
- * (loop masks off __GFP_IO|__GFP_FS for this reason);
- * but more thought would probably show more reasons.
- *
- * Don't require __GFP_FS, since we're not going into
- * the FS, just waiting on its writeback completion.
- * Worryingly, ext4 gfs2 and xfs allocate pages with
- * grab_cache_page_write_begin(,,AOP_FLAG_NOFS), so
- * testing may_enter_fs here is liable to OOM on them.
- */
- if (global_reclaim(sc) ||
+ /* Case 1 above */
+ if (current_is_kswapd() &&
+ PageReclaim(page) &&
+ zone_is_reclaim_writeback(zone)) {
+ nr_immediate++;
+ goto keep_locked;
+
+ /* Case 2 above */
+ } else if (global_reclaim(sc) ||
!PageReclaim(page) || !(sc->gfp_mask & __GFP_IO)) {
/*
* This is slightly racy - end_page_writeback()
@@ -756,9 +842,13 @@
*/
SetPageReclaim(page);
nr_writeback++;
+
goto keep_locked;
+
+ /* Case 3 above */
+ } else {
+ wait_on_page_writeback(page);
}
- wait_on_page_writeback(page);
}
if (!force_reclaim)
@@ -784,9 +874,10 @@
if (!add_to_swap(page, page_list))
goto activate_locked;
may_enter_fs = 1;
- }
- mapping = page_mapping(page);
+ /* Adding to swap updated mapping */
+ mapping = page_mapping(page);
+ }
/*
* The page is mapped into the page tables of one or more
@@ -806,16 +897,14 @@
}
if (PageDirty(page)) {
- nr_dirty++;
-
/*
* Only kswapd can writeback filesystem pages to
- * avoid risk of stack overflow but do not writeback
- * unless under significant pressure.
+ * avoid risk of stack overflow but only writeback
+ * if many dirty pages have been encountered.
*/
if (page_is_file_cache(page) &&
(!current_is_kswapd() ||
- sc->priority >= DEF_PRIORITY - 2)) {
+ !zone_is_reclaim_dirty(zone))) {
/*
* Immediately reclaim when written back.
* Similar in principal to deactivate_page()
@@ -838,7 +927,6 @@
/* Page is dirty, try to write it out here */
switch (pageout(page, mapping, sc)) {
case PAGE_KEEP:
- nr_congested++;
goto keep_locked;
case PAGE_ACTIVATE:
goto activate_locked;
@@ -946,22 +1034,16 @@
VM_BUG_ON(PageLRU(page) || PageUnevictable(page));
}
- /*
- * Tag a zone as congested if all the dirty pages encountered were
- * backed by a congested BDI. In this case, reclaimers should just
- * back off and wait for congestion to clear because further reclaim
- * will encounter the same problem
- */
- if (nr_dirty && nr_dirty == nr_congested && global_reclaim(sc))
- zone_set_flag(zone, ZONE_CONGESTED);
-
free_hot_cold_page_list(&free_pages, 1);
list_splice(&ret_pages, page_list);
count_vm_events(PGACTIVATE, pgactivate);
mem_cgroup_uncharge_end();
*ret_nr_dirty += nr_dirty;
+ *ret_nr_congested += nr_congested;
+ *ret_nr_unqueued_dirty += nr_unqueued_dirty;
*ret_nr_writeback += nr_writeback;
+ *ret_nr_immediate += nr_immediate;
return nr_reclaimed;
}
@@ -973,7 +1055,7 @@
.priority = DEF_PRIORITY,
.may_unmap = 1,
};
- unsigned long ret, dummy1, dummy2;
+ unsigned long ret, dummy1, dummy2, dummy3, dummy4, dummy5;
struct page *page, *next;
LIST_HEAD(clean_pages);
@@ -985,8 +1067,8 @@
}
ret = shrink_page_list(&clean_pages, zone, &sc,
- TTU_UNMAP|TTU_IGNORE_ACCESS,
- &dummy1, &dummy2, true);
+ TTU_UNMAP|TTU_IGNORE_ACCESS,
+ &dummy1, &dummy2, &dummy3, &dummy4, &dummy5, true);
list_splice(&clean_pages, page_list);
__mod_zone_page_state(zone, NR_ISOLATED_FILE, -ret);
return ret;
@@ -1281,7 +1363,10 @@
unsigned long nr_reclaimed = 0;
unsigned long nr_taken;
unsigned long nr_dirty = 0;
+ unsigned long nr_congested = 0;
+ unsigned long nr_unqueued_dirty = 0;
unsigned long nr_writeback = 0;
+ unsigned long nr_immediate = 0;
isolate_mode_t isolate_mode = 0;
int file = is_file_lru(lru);
struct zone *zone = lruvec_zone(lruvec);
@@ -1323,7 +1408,9 @@
return 0;
nr_reclaimed = shrink_page_list(&page_list, zone, sc, TTU_UNMAP,
- &nr_dirty, &nr_writeback, false);
+ &nr_dirty, &nr_unqueued_dirty, &nr_congested,
+ &nr_writeback, &nr_immediate,
+ false);
spin_lock_irq(&zone->lru_lock);
@@ -1356,21 +1443,51 @@
* as there is no guarantee the dirtying process is throttled in the
* same way balance_dirty_pages() manages.
*
- * This scales the number of dirty pages that must be under writeback
- * before throttling depending on priority. It is a simple backoff
- * function that has the most effect in the range DEF_PRIORITY to
- * DEF_PRIORITY-2 which is the priority reclaim is considered to be
- * in trouble and reclaim is considered to be in trouble.
- *
- * DEF_PRIORITY 100% isolated pages must be PageWriteback to throttle
- * DEF_PRIORITY-1 50% must be PageWriteback
- * DEF_PRIORITY-2 25% must be PageWriteback, kswapd in trouble
- * ...
- * DEF_PRIORITY-6 For SWAP_CLUSTER_MAX isolated pages, throttle if any
- * isolated page is PageWriteback
+ * Once a zone is flagged ZONE_WRITEBACK, kswapd will count the number
+ * of pages under pages flagged for immediate reclaim and stall if any
+ * are encountered in the nr_immediate check below.
*/
- if (nr_writeback && nr_writeback >=
- (nr_taken >> (DEF_PRIORITY - sc->priority)))
+ if (nr_writeback && nr_writeback == nr_taken)
+ zone_set_flag(zone, ZONE_WRITEBACK);
+
+ /*
+ * memcg will stall in page writeback so only consider forcibly
+ * stalling for global reclaim
+ */
+ if (global_reclaim(sc)) {
+ /*
+ * Tag a zone as congested if all the dirty pages scanned were
+ * backed by a congested BDI and wait_iff_congested will stall.
+ */
+ if (nr_dirty && nr_dirty == nr_congested)
+ zone_set_flag(zone, ZONE_CONGESTED);
+
+ /*
+ * If dirty pages are scanned that are not queued for IO, it
+ * implies that flushers are not keeping up. In this case, flag
+ * the zone ZONE_TAIL_LRU_DIRTY and kswapd will start writing
+ * pages from reclaim context. It will forcibly stall in the
+ * next check.
+ */
+ if (nr_unqueued_dirty == nr_taken)
+ zone_set_flag(zone, ZONE_TAIL_LRU_DIRTY);
+
+ /*
+ * In addition, if kswapd scans pages marked marked for
+ * immediate reclaim and under writeback (nr_immediate), it
+ * implies that pages are cycling through the LRU faster than
+ * they are written so also forcibly stall.
+ */
+ if (nr_unqueued_dirty == nr_taken || nr_immediate)
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
+ }
+
+ /*
+ * Stall direct reclaim for IO completions if underlying BDIs or zone
+ * is congested. Allow kswapd to continue until it starts encountering
+ * unqueued dirty pages or cycling through the LRU too quickly.
+ */
+ if (!sc->hibernation_mode && !current_is_kswapd())
wait_iff_congested(zone, BLK_RW_ASYNC, HZ/10);
trace_mm_vmscan_lru_shrink_inactive(zone->zone_pgdat->node_id,
@@ -1822,17 +1939,25 @@
static void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc)
{
unsigned long nr[NR_LRU_LISTS];
+ unsigned long targets[NR_LRU_LISTS];
unsigned long nr_to_scan;
enum lru_list lru;
unsigned long nr_reclaimed = 0;
unsigned long nr_to_reclaim = sc->nr_to_reclaim;
struct blk_plug plug;
+ bool scan_adjusted = false;
get_scan_count(lruvec, sc, nr);
+ /* Record the original scan target for proportional adjustments later */
+ memcpy(targets, nr, sizeof(nr));
+
blk_start_plug(&plug);
while (nr[LRU_INACTIVE_ANON] || nr[LRU_ACTIVE_FILE] ||
nr[LRU_INACTIVE_FILE]) {
+ unsigned long nr_anon, nr_file, percentage;
+ unsigned long nr_scanned;
+
for_each_evictable_lru(lru) {
if (nr[lru]) {
nr_to_scan = min(nr[lru], SWAP_CLUSTER_MAX);
@@ -1842,17 +1967,60 @@
lruvec, sc);
}
}
+
+ if (nr_reclaimed < nr_to_reclaim || scan_adjusted)
+ continue;
+
/*
- * On large memory systems, scan >> priority can become
- * really large. This is fine for the starting priority;
- * we want to put equal scanning pressure on each zone.
- * However, if the VM has a harder time of freeing pages,
- * with multiple processes reclaiming pages, the total
- * freeing target can get unreasonably large.
+ * For global direct reclaim, reclaim only the number of pages
+ * requested. Less care is taken to scan proportionally as it
+ * is more important to minimise direct reclaim stall latency
+ * than it is to properly age the LRU lists.
*/
- if (nr_reclaimed >= nr_to_reclaim &&
- sc->priority < DEF_PRIORITY)
+ if (global_reclaim(sc) && !current_is_kswapd())
break;
+
+ /*
+ * For kswapd and memcg, reclaim at least the number of pages
+ * requested. Ensure that the anon and file LRUs shrink
+ * proportionally what was requested by get_scan_count(). We
+ * stop reclaiming one LRU and reduce the amount scanning
+ * proportional to the original scan target.
+ */
+ nr_file = nr[LRU_INACTIVE_FILE] + nr[LRU_ACTIVE_FILE];
+ nr_anon = nr[LRU_INACTIVE_ANON] + nr[LRU_ACTIVE_ANON];
+
+ if (nr_file > nr_anon) {
+ unsigned long scan_target = targets[LRU_INACTIVE_ANON] +
+ targets[LRU_ACTIVE_ANON] + 1;
+ lru = LRU_BASE;
+ percentage = nr_anon * 100 / scan_target;
+ } else {
+ unsigned long scan_target = targets[LRU_INACTIVE_FILE] +
+ targets[LRU_ACTIVE_FILE] + 1;
+ lru = LRU_FILE;
+ percentage = nr_file * 100 / scan_target;
+ }
+
+ /* Stop scanning the smaller of the LRU */
+ nr[lru] = 0;
+ nr[lru + LRU_ACTIVE] = 0;
+
+ /*
+ * Recalculate the other LRU scan count based on its original
+ * scan target and the percentage scanning already complete
+ */
+ lru = (lru == LRU_FILE) ? LRU_BASE : LRU_FILE;
+ nr_scanned = targets[lru] - nr[lru];
+ nr[lru] = targets[lru] * (100 - percentage) / 100;
+ nr[lru] -= min(nr[lru], nr_scanned);
+
+ lru += LRU_ACTIVE;
+ nr_scanned = targets[lru] - nr[lru];
+ nr[lru] = targets[lru] * (100 - percentage) / 100;
+ nr[lru] -= min(nr[lru], nr_scanned);
+
+ scan_adjusted = true;
}
blk_finish_plug(&plug);
sc->nr_reclaimed += nr_reclaimed;
@@ -2179,8 +2347,10 @@
aborted_reclaim = shrink_zones(zonelist, sc);
/*
- * Don't shrink slabs when reclaiming memory from
- * over limit cgroups
+ * Don't shrink slabs when reclaiming memory from over limit
+ * cgroups but do shrink slab at least once when aborting
+ * reclaim for compaction to avoid unevenly scanning file/anon
+ * LRU pages over slab pages.
*/
if (global_reclaim(sc)) {
unsigned long lru_pages = 0;
@@ -2222,18 +2392,7 @@
WB_REASON_TRY_TO_FREE_PAGES);
sc->may_writepage = 1;
}
-
- /* Take a nap, wait for some writeback to complete */
- if (!sc->hibernation_mode && sc->nr_scanned &&
- sc->priority < DEF_PRIORITY - 2) {
- struct zone *preferred_zone;
-
- first_zones_zonelist(zonelist, gfp_zone(sc->gfp_mask),
- &cpuset_current_mems_allowed,
- &preferred_zone);
- wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/10);
- }
- } while (--sc->priority >= 0);
+ } while (--sc->priority >= 0 && !aborted_reclaim);
out:
delayacct_freepages_end();
@@ -2601,6 +2760,91 @@
}
/*
+ * kswapd shrinks the zone by the number of pages required to reach
+ * the high watermark.
+ *
+ * Returns true if kswapd scanned at least the requested number of pages to
+ * reclaim or if the lack of progress was due to pages under writeback.
+ * This is used to determine if the scanning priority needs to be raised.
+ */
+static bool kswapd_shrink_zone(struct zone *zone,
+ int classzone_idx,
+ struct scan_control *sc,
+ unsigned long lru_pages,
+ unsigned long *nr_attempted)
+{
+ unsigned long nr_slab;
+ int testorder = sc->order;
+ unsigned long balance_gap;
+ struct reclaim_state *reclaim_state = current->reclaim_state;
+ struct shrink_control shrink = {
+ .gfp_mask = sc->gfp_mask,
+ };
+ bool lowmem_pressure;
+
+ /* Reclaim above the high watermark. */
+ sc->nr_to_reclaim = max(SWAP_CLUSTER_MAX, high_wmark_pages(zone));
+
+ /*
+ * Kswapd reclaims only single pages with compaction enabled. Trying
+ * too hard to reclaim until contiguous free pages have become
+ * available can hurt performance by evicting too much useful data
+ * from memory. Do not reclaim more than needed for compaction.
+ */
+ if (IS_ENABLED(CONFIG_COMPACTION) && sc->order &&
+ compaction_suitable(zone, sc->order) !=
+ COMPACT_SKIPPED)
+ testorder = 0;
+
+ /*
+ * We put equal pressure on every zone, unless one zone has way too
+ * many pages free already. The "too many pages" is defined as the
+ * high wmark plus a "gap" where the gap is either the low
+ * watermark or 1% of the zone, whichever is smaller.
+ */
+ balance_gap = min(low_wmark_pages(zone),
+ (zone->managed_pages + KSWAPD_ZONE_BALANCE_GAP_RATIO-1) /
+ KSWAPD_ZONE_BALANCE_GAP_RATIO);
+
+ /*
+ * If there is no low memory pressure or the zone is balanced then no
+ * reclaim is necessary
+ */
+ lowmem_pressure = (buffer_heads_over_limit && is_highmem(zone));
+ if (!lowmem_pressure && zone_balanced(zone, testorder,
+ balance_gap, classzone_idx))
+ return true;
+
+ shrink_zone(zone, sc);
+
+ reclaim_state->reclaimed_slab = 0;
+ nr_slab = shrink_slab(&shrink, sc->nr_scanned, lru_pages);
+ sc->nr_reclaimed += reclaim_state->reclaimed_slab;
+
+ /* Account for the number of pages attempted to reclaim */
+ *nr_attempted += sc->nr_to_reclaim;
+
+ if (nr_slab == 0 && !zone_reclaimable(zone))
+ zone->all_unreclaimable = 1;
+
+ zone_clear_flag(zone, ZONE_WRITEBACK);
+
+ /*
+ * If a zone reaches its high watermark, consider it to be no longer
+ * congested. It's possible there are dirty pages backed by congested
+ * BDIs but as pressure is relieved, speculatively avoid congestion
+ * waits.
+ */
+ if (!zone->all_unreclaimable &&
+ zone_balanced(zone, testorder, 0, classzone_idx)) {
+ zone_clear_flag(zone, ZONE_CONGESTED);
+ zone_clear_flag(zone, ZONE_TAIL_LRU_DIRTY);
+ }
+
+ return sc->nr_scanned >= sc->nr_to_reclaim;
+}
+
+/*
* For kswapd, balance_pgdat() will work across all this node's zones until
* they are all at high_wmark_pages(zone).
*
@@ -2624,35 +2868,28 @@
static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
int *classzone_idx)
{
- bool pgdat_is_balanced = false;
int i;
int end_zone = 0; /* Inclusive. 0 = ZONE_DMA */
- struct reclaim_state *reclaim_state = current->reclaim_state;
unsigned long nr_soft_reclaimed;
unsigned long nr_soft_scanned;
struct scan_control sc = {
.gfp_mask = GFP_KERNEL,
+ .priority = DEF_PRIORITY,
.may_unmap = 1,
.may_swap = 1,
- /*
- * kswapd doesn't want to be bailed out while reclaim. because
- * we want to put equal scanning pressure on each zone.
- */
- .nr_to_reclaim = ULONG_MAX,
+ .may_writepage = !laptop_mode,
.order = order,
.target_mem_cgroup = NULL,
};
- struct shrink_control shrink = {
- .gfp_mask = sc.gfp_mask,
- };
-loop_again:
- sc.priority = DEF_PRIORITY;
- sc.nr_reclaimed = 0;
- sc.may_writepage = !laptop_mode;
count_vm_event(PAGEOUTRUN);
do {
unsigned long lru_pages = 0;
+ unsigned long nr_attempted = 0;
+ bool raise_priority = true;
+ bool pgdat_needs_compaction = (order > 0);
+
+ sc.nr_reclaimed = 0;
/*
* Scan in the highmem->dma direction for the highest
@@ -2689,23 +2926,46 @@
end_zone = i;
break;
} else {
- /* If balanced, clear the congested flag */
+ /*
+ * If balanced, clear the dirty and congested
+ * flags
+ */
zone_clear_flag(zone, ZONE_CONGESTED);
+ zone_clear_flag(zone, ZONE_TAIL_LRU_DIRTY);
}
}
- if (i < 0) {
- pgdat_is_balanced = true;
+ if (i < 0)
goto out;
- }
for (i = 0; i <= end_zone; i++) {
struct zone *zone = pgdat->node_zones + i;
+ if (!populated_zone(zone))
+ continue;
+
lru_pages += zone_reclaimable_pages(zone);
+
+ /*
+ * If any zone is currently balanced then kswapd will
+ * not call compaction as it is expected that the
+ * necessary pages are already available.
+ */
+ if (pgdat_needs_compaction &&
+ zone_watermark_ok(zone, order,
+ low_wmark_pages(zone),
+ *classzone_idx, 0))
+ pgdat_needs_compaction = false;
}
/*
+ * If we're getting trouble reclaiming, start doing writepage
+ * even in laptop mode.
+ */
+ if (sc.priority < DEF_PRIORITY - 2)
+ sc.may_writepage = 1;
+
+ /*
* Now scan the zone in the dma->highmem direction, stopping
* at the last zone which needs scanning.
*
@@ -2716,8 +2976,6 @@
*/
for (i = 0; i <= end_zone; i++) {
struct zone *zone = pgdat->node_zones + i;
- int nr_slab, testorder;
- unsigned long balance_gap;
if (!populated_zone(zone))
continue;
@@ -2738,65 +2996,14 @@
sc.nr_reclaimed += nr_soft_reclaimed;
/*
- * We put equal pressure on every zone, unless
- * one zone has way too many pages free
- * already. The "too many pages" is defined
- * as the high wmark plus a "gap" where the
- * gap is either the low watermark or 1%
- * of the zone, whichever is smaller.
+ * There should be no need to raise the scanning
+ * priority if enough pages are already being scanned
+ * that that high watermark would be met at 100%
+ * efficiency.
*/
- balance_gap = min(low_wmark_pages(zone),
- (zone->managed_pages +
- KSWAPD_ZONE_BALANCE_GAP_RATIO-1) /
- KSWAPD_ZONE_BALANCE_GAP_RATIO);
- /*
- * Kswapd reclaims only single pages with compaction
- * enabled. Trying too hard to reclaim until contiguous
- * free pages have become available can hurt performance
- * by evicting too much useful data from memory.
- * Do not reclaim more than needed for compaction.
- */
- testorder = order;
- if (IS_ENABLED(CONFIG_COMPACTION) && order &&
- compaction_suitable(zone, order) !=
- COMPACT_SKIPPED)
- testorder = 0;
-
- if ((buffer_heads_over_limit && is_highmem_idx(i)) ||
- !zone_balanced(zone, testorder,
- balance_gap, end_zone)) {
- shrink_zone(zone, &sc);
-
- reclaim_state->reclaimed_slab = 0;
- nr_slab = shrink_slab(&shrink, sc.nr_scanned, lru_pages);
- sc.nr_reclaimed += reclaim_state->reclaimed_slab;
-
- if (nr_slab == 0 && !zone_reclaimable(zone))
- zone->all_unreclaimable = 1;
- }
-
- /*
- * If we're getting trouble reclaiming, start doing
- * writepage even in laptop mode.
- */
- if (sc.priority < DEF_PRIORITY - 2)
- sc.may_writepage = 1;
-
- if (zone->all_unreclaimable) {
- if (end_zone && end_zone == i)
- end_zone--;
- continue;
- }
-
- if (zone_balanced(zone, testorder, 0, end_zone))
- /*
- * If a zone reaches its high watermark,
- * consider it to be no longer congested. It's
- * possible there are dirty pages backed by
- * congested BDIs but as pressure is relieved,
- * speculatively avoid congestion waits
- */
- zone_clear_flag(zone, ZONE_CONGESTED);
+ if (kswapd_shrink_zone(zone, end_zone, &sc,
+ lru_pages, &nr_attempted))
+ raise_priority = false;
}
/*
@@ -2808,74 +3015,38 @@
pfmemalloc_watermark_ok(pgdat))
wake_up(&pgdat->pfmemalloc_wait);
- if (pgdat_balanced(pgdat, order, *classzone_idx)) {
- pgdat_is_balanced = true;
- break; /* kswapd: all done */
- }
-
/*
- * We do this so kswapd doesn't build up large priorities for
- * example when it is freeing in parallel with allocators. It
- * matches the direct reclaim path behaviour in terms of impact
- * on zone->*_priority.
+ * Fragmentation may mean that the system cannot be rebalanced
+ * for high-order allocations in all zones. If twice the
+ * allocation size has been reclaimed and the zones are still
+ * not balanced then recheck the watermarks at order-0 to
+ * prevent kswapd reclaiming excessively. Assume that a
+ * process requested a high-order can direct reclaim/compact.
*/
- if (sc.nr_reclaimed >= SWAP_CLUSTER_MAX)
- break;
- } while (--sc.priority >= 0);
-
-out:
- if (!pgdat_is_balanced) {
- cond_resched();
-
- try_to_freeze();
-
- /*
- * Fragmentation may mean that the system cannot be
- * rebalanced for high-order allocations in all zones.
- * At this point, if nr_reclaimed < SWAP_CLUSTER_MAX,
- * it means the zones have been fully scanned and are still
- * not balanced. For high-order allocations, there is
- * little point trying all over again as kswapd may
- * infinite loop.
- *
- * Instead, recheck all watermarks at order-0 as they
- * are the most important. If watermarks are ok, kswapd will go
- * back to sleep. High-order users can still perform direct
- * reclaim if they wish.
- */
- if (sc.nr_reclaimed < SWAP_CLUSTER_MAX)
+ if (order && sc.nr_reclaimed >= 2UL << order)
order = sc.order = 0;
- goto loop_again;
- }
+ /* Check if kswapd should be suspending */
+ if (try_to_freeze() || kthread_should_stop())
+ break;
- /*
- * If kswapd was reclaiming at a higher order, it has the option of
- * sleeping without all zones being balanced. Before it does, it must
- * ensure that the watermarks for order-0 on *all* zones are met and
- * that the congestion flags are cleared. The congestion flag must
- * be cleared as kswapd is the only mechanism that clears the flag
- * and it is potentially going to sleep here.
- */
- if (order) {
- int zones_need_compaction = 1;
-
- for (i = 0; i <= end_zone; i++) {
- struct zone *zone = pgdat->node_zones + i;
-
- if (!populated_zone(zone))
- continue;
-
- /* Check if the memory needs to be defragmented. */
- if (zone_watermark_ok(zone, order,
- low_wmark_pages(zone), *classzone_idx, 0))
- zones_need_compaction = 0;
- }
-
- if (zones_need_compaction)
+ /*
+ * Compact if necessary and kswapd is reclaiming at least the
+ * high watermark number of pages as requsted
+ */
+ if (pgdat_needs_compaction && sc.nr_reclaimed > nr_attempted)
compact_pgdat(pgdat, order);
- }
+ /*
+ * Raise priority if scanning rate is too low or there was no
+ * progress in reclaiming pages
+ */
+ if (raise_priority || !sc.nr_reclaimed)
+ sc.priority--;
+ } while (sc.priority >= 1 &&
+ !pgdat_balanced(pgdat, order, *classzone_idx));
+
+out:
/*
* Return the order we were reclaiming at so prepare_kswapd_sleep()
* makes a decision on the order we were last reclaiming at. However,
diff --git a/mm/zbud.c b/mm/zbud.c
new file mode 100644
index 0000000..9bb4710
--- /dev/null
+++ b/mm/zbud.c
@@ -0,0 +1,527 @@
+/*
+ * zbud.c
+ *
+ * Copyright (C) 2013, Seth Jennings, IBM
+ *
+ * Concepts based on zcache internal zbud allocator by Dan Magenheimer.
+ *
+ * zbud is an special purpose allocator for storing compressed pages. Contrary
+ * to what its name may suggest, zbud is not a buddy allocator, but rather an
+ * allocator that "buddies" two compressed pages together in a single memory
+ * page.
+ *
+ * While this design limits storage density, it has simple and deterministic
+ * reclaim properties that make it preferable to a higher density approach when
+ * reclaim will be used.
+ *
+ * zbud works by storing compressed pages, or "zpages", together in pairs in a
+ * single memory page called a "zbud page". The first buddy is "left
+ * justifed" at the beginning of the zbud page, and the last buddy is "right
+ * justified" at the end of the zbud page. The benefit is that if either
+ * buddy is freed, the freed buddy space, coalesced with whatever slack space
+ * that existed between the buddies, results in the largest possible free region
+ * within the zbud page.
+ *
+ * zbud also provides an attractive lower bound on density. The ratio of zpages
+ * to zbud pages can not be less than 1. This ensures that zbud can never "do
+ * harm" by using more pages to store zpages than the uncompressed zpages would
+ * have used on their own.
+ *
+ * zbud pages are divided into "chunks". The size of the chunks is fixed at
+ * compile time and determined by NCHUNKS_ORDER below. Dividing zbud pages
+ * into chunks allows organizing unbuddied zbud pages into a manageable number
+ * of unbuddied lists according to the number of free chunks available in the
+ * zbud page.
+ *
+ * The zbud API differs from that of conventional allocators in that the
+ * allocation function, zbud_alloc(), returns an opaque handle to the user,
+ * not a dereferenceable pointer. The user must map the handle using
+ * zbud_map() in order to get a usable pointer by which to access the
+ * allocation data and unmap the handle with zbud_unmap() when operations
+ * on the allocation data are complete.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/atomic.h>
+#include <linux/list.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/preempt.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/zbud.h>
+
+/*****************
+ * Structures
+*****************/
+/*
+ * NCHUNKS_ORDER determines the internal allocation granularity, effectively
+ * adjusting internal fragmentation. It also determines the number of
+ * freelists maintained in each pool. NCHUNKS_ORDER of 6 means that the
+ * allocation granularity will be in chunks of size PAGE_SIZE/64, and there
+ * will be 64 freelists per pool.
+ */
+#define NCHUNKS_ORDER 6
+
+#define CHUNK_SHIFT (PAGE_SHIFT - NCHUNKS_ORDER)
+#define CHUNK_SIZE (1 << CHUNK_SHIFT)
+#define NCHUNKS (PAGE_SIZE >> CHUNK_SHIFT)
+#define ZHDR_SIZE_ALIGNED CHUNK_SIZE
+
+/**
+ * struct zbud_pool - stores metadata for each zbud pool
+ * @lock: protects all pool fields and first|last_chunk fields of any
+ * zbud page in the pool
+ * @unbuddied: array of lists tracking zbud pages that only contain one buddy;
+ * the lists each zbud page is added to depends on the size of
+ * its free region.
+ * @buddied: list tracking the zbud pages that contain two buddies;
+ * these zbud pages are full
+ * @lru: list tracking the zbud pages in LRU order by most recently
+ * added buddy.
+ * @pages_nr: number of zbud pages in the pool.
+ * @ops: pointer to a structure of user defined operations specified at
+ * pool creation time.
+ *
+ * This structure is allocated at pool creation time and maintains metadata
+ * pertaining to a particular zbud pool.
+ */
+struct zbud_pool {
+ spinlock_t lock;
+ struct list_head unbuddied[NCHUNKS];
+ struct list_head buddied;
+ struct list_head lru;
+ u64 pages_nr;
+ struct zbud_ops *ops;
+};
+
+/*
+ * struct zbud_header - zbud page metadata occupying the first chunk of each
+ * zbud page.
+ * @buddy: links the zbud page into the unbuddied/buddied lists in the pool
+ * @lru: links the zbud page into the lru list in the pool
+ * @first_chunks: the size of the first buddy in chunks, 0 if free
+ * @last_chunks: the size of the last buddy in chunks, 0 if free
+ */
+struct zbud_header {
+ struct list_head buddy;
+ struct list_head lru;
+ unsigned int first_chunks;
+ unsigned int last_chunks;
+ bool under_reclaim;
+};
+
+/*****************
+ * Helpers
+*****************/
+/* Just to make the code easier to read */
+enum buddy {
+ FIRST,
+ LAST
+};
+
+/* Converts an allocation size in bytes to size in zbud chunks */
+static int size_to_chunks(int size)
+{
+ return (size + CHUNK_SIZE - 1) >> CHUNK_SHIFT;
+}
+
+#define for_each_unbuddied_list(_iter, _begin) \
+ for ((_iter) = (_begin); (_iter) < NCHUNKS; (_iter)++)
+
+/* Initializes the zbud header of a newly allocated zbud page */
+static struct zbud_header *init_zbud_page(struct page *page)
+{
+ struct zbud_header *zhdr = page_address(page);
+ zhdr->first_chunks = 0;
+ zhdr->last_chunks = 0;
+ INIT_LIST_HEAD(&zhdr->buddy);
+ INIT_LIST_HEAD(&zhdr->lru);
+ zhdr->under_reclaim = 0;
+ return zhdr;
+}
+
+/* Resets the struct page fields and frees the page */
+static void free_zbud_page(struct zbud_header *zhdr)
+{
+ __free_page(virt_to_page(zhdr));
+}
+
+/*
+ * Encodes the handle of a particular buddy within a zbud page
+ * Pool lock should be held as this function accesses first|last_chunks
+ */
+static unsigned long encode_handle(struct zbud_header *zhdr, enum buddy bud)
+{
+ unsigned long handle;
+
+ /*
+ * For now, the encoded handle is actually just the pointer to the data
+ * but this might not always be the case. A little information hiding.
+ * Add CHUNK_SIZE to the handle if it is the first allocation to jump
+ * over the zbud header in the first chunk.
+ */
+ handle = (unsigned long)zhdr;
+ if (bud == FIRST)
+ /* skip over zbud header */
+ handle += ZHDR_SIZE_ALIGNED;
+ else /* bud == LAST */
+ handle += PAGE_SIZE - (zhdr->last_chunks << CHUNK_SHIFT);
+ return handle;
+}
+
+/* Returns the zbud page where a given handle is stored */
+static struct zbud_header *handle_to_zbud_header(unsigned long handle)
+{
+ return (struct zbud_header *)(handle & PAGE_MASK);
+}
+
+/* Returns the number of free chunks in a zbud page */
+static int num_free_chunks(struct zbud_header *zhdr)
+{
+ /*
+ * Rather than branch for different situations, just use the fact that
+ * free buddies have a length of zero to simplify everything. -1 at the
+ * end for the zbud header.
+ */
+ return NCHUNKS - zhdr->first_chunks - zhdr->last_chunks - 1;
+}
+
+/*****************
+ * API Functions
+*****************/
+/**
+ * zbud_create_pool() - create a new zbud pool
+ * @gfp: gfp flags when allocating the zbud pool structure
+ * @ops: user-defined operations for the zbud pool
+ *
+ * Return: pointer to the new zbud pool or NULL if the metadata allocation
+ * failed.
+ */
+struct zbud_pool *zbud_create_pool(gfp_t gfp, struct zbud_ops *ops)
+{
+ struct zbud_pool *pool;
+ int i;
+
+ pool = kmalloc(sizeof(struct zbud_pool), gfp);
+ if (!pool)
+ return NULL;
+ spin_lock_init(&pool->lock);
+ for_each_unbuddied_list(i, 0)
+ INIT_LIST_HEAD(&pool->unbuddied[i]);
+ INIT_LIST_HEAD(&pool->buddied);
+ INIT_LIST_HEAD(&pool->lru);
+ pool->pages_nr = 0;
+ pool->ops = ops;
+ return pool;
+}
+
+/**
+ * zbud_destroy_pool() - destroys an existing zbud pool
+ * @pool: the zbud pool to be destroyed
+ *
+ * The pool should be emptied before this function is called.
+ */
+void zbud_destroy_pool(struct zbud_pool *pool)
+{
+ kfree(pool);
+}
+
+/**
+ * zbud_alloc() - allocates a region of a given size
+ * @pool: zbud pool from which to allocate
+ * @size: size in bytes of the desired allocation
+ * @gfp: gfp flags used if the pool needs to grow
+ * @handle: handle of the new allocation
+ *
+ * This function will attempt to find a free region in the pool large enough to
+ * satisfy the allocation request. A search of the unbuddied lists is
+ * performed first. If no suitable free region is found, then a new page is
+ * allocated and added to the pool to satisfy the request.
+ *
+ * gfp should not set __GFP_HIGHMEM as highmem pages cannot be used
+ * as zbud pool pages.
+ *
+ * Return: 0 if success and handle is set, otherwise -EINVAL is the size or
+ * gfp arguments are invalid or -ENOMEM if the pool was unable to allocate
+ * a new page.
+ */
+int zbud_alloc(struct zbud_pool *pool, int size, gfp_t gfp,
+ unsigned long *handle)
+{
+ int chunks, i, freechunks;
+ struct zbud_header *zhdr = NULL;
+ enum buddy bud;
+ struct page *page;
+
+ if (size <= 0 || gfp & __GFP_HIGHMEM)
+ return -EINVAL;
+ if (size > PAGE_SIZE - ZHDR_SIZE_ALIGNED)
+ return -ENOSPC;
+ chunks = size_to_chunks(size);
+ spin_lock(&pool->lock);
+
+ /* First, try to find an unbuddied zbud page. */
+ zhdr = NULL;
+ for_each_unbuddied_list(i, chunks) {
+ if (!list_empty(&pool->unbuddied[i])) {
+ zhdr = list_first_entry(&pool->unbuddied[i],
+ struct zbud_header, buddy);
+ list_del(&zhdr->buddy);
+ if (zhdr->first_chunks == 0)
+ bud = FIRST;
+ else
+ bud = LAST;
+ goto found;
+ }
+ }
+
+ /* Couldn't find unbuddied zbud page, create new one */
+ spin_unlock(&pool->lock);
+ page = alloc_page(gfp);
+ if (!page)
+ return -ENOMEM;
+ spin_lock(&pool->lock);
+ pool->pages_nr++;
+ zhdr = init_zbud_page(page);
+ bud = FIRST;
+
+found:
+ if (bud == FIRST)
+ zhdr->first_chunks = chunks;
+ else
+ zhdr->last_chunks = chunks;
+
+ if (zhdr->first_chunks == 0 || zhdr->last_chunks == 0) {
+ /* Add to unbuddied list */
+ freechunks = num_free_chunks(zhdr);
+ list_add(&zhdr->buddy, &pool->unbuddied[freechunks]);
+ } else {
+ /* Add to buddied list */
+ list_add(&zhdr->buddy, &pool->buddied);
+ }
+
+ /* Add/move zbud page to beginning of LRU */
+ if (!list_empty(&zhdr->lru))
+ list_del(&zhdr->lru);
+ list_add(&zhdr->lru, &pool->lru);
+
+ *handle = encode_handle(zhdr, bud);
+ spin_unlock(&pool->lock);
+
+ return 0;
+}
+
+/**
+ * zbud_free() - frees the allocation associated with the given handle
+ * @pool: pool in which the allocation resided
+ * @handle: handle associated with the allocation returned by zbud_alloc()
+ *
+ * In the case that the zbud page in which the allocation resides is under
+ * reclaim, as indicated by the PG_reclaim flag being set, this function
+ * only sets the first|last_chunks to 0. The page is actually freed
+ * once both buddies are evicted (see zbud_reclaim_page() below).
+ */
+void zbud_free(struct zbud_pool *pool, unsigned long handle)
+{
+ struct zbud_header *zhdr;
+ int freechunks;
+
+ spin_lock(&pool->lock);
+ zhdr = handle_to_zbud_header(handle);
+
+ /* If first buddy, handle will be page aligned */
+ if ((handle - ZHDR_SIZE_ALIGNED) & ~PAGE_MASK)
+ zhdr->last_chunks = 0;
+ else
+ zhdr->first_chunks = 0;
+
+ if (zhdr->under_reclaim) {
+ /* zbud page is under reclaim, reclaim will free */
+ spin_unlock(&pool->lock);
+ return;
+ }
+
+ /* Remove from existing buddy list */
+ list_del(&zhdr->buddy);
+
+ if (zhdr->first_chunks == 0 && zhdr->last_chunks == 0) {
+ /* zbud page is empty, free */
+ list_del(&zhdr->lru);
+ free_zbud_page(zhdr);
+ pool->pages_nr--;
+ } else {
+ /* Add to unbuddied list */
+ freechunks = num_free_chunks(zhdr);
+ list_add(&zhdr->buddy, &pool->unbuddied[freechunks]);
+ }
+
+ spin_unlock(&pool->lock);
+}
+
+#define list_tail_entry(ptr, type, member) \
+ list_entry((ptr)->prev, type, member)
+
+/**
+ * zbud_reclaim_page() - evicts allocations from a pool page and frees it
+ * @pool: pool from which a page will attempt to be evicted
+ * @retires: number of pages on the LRU list for which eviction will
+ * be attempted before failing
+ *
+ * zbud reclaim is different from normal system reclaim in that the reclaim is
+ * done from the bottom, up. This is because only the bottom layer, zbud, has
+ * information on how the allocations are organized within each zbud page. This
+ * has the potential to create interesting locking situations between zbud and
+ * the user, however.
+ *
+ * To avoid these, this is how zbud_reclaim_page() should be called:
+
+ * The user detects a page should be reclaimed and calls zbud_reclaim_page().
+ * zbud_reclaim_page() will remove a zbud page from the pool LRU list and call
+ * the user-defined eviction handler with the pool and handle as arguments.
+ *
+ * If the handle can not be evicted, the eviction handler should return
+ * non-zero. zbud_reclaim_page() will add the zbud page back to the
+ * appropriate list and try the next zbud page on the LRU up to
+ * a user defined number of retries.
+ *
+ * If the handle is successfully evicted, the eviction handler should
+ * return 0 _and_ should have called zbud_free() on the handle. zbud_free()
+ * contains logic to delay freeing the page if the page is under reclaim,
+ * as indicated by the setting of the PG_reclaim flag on the underlying page.
+ *
+ * If all buddies in the zbud page are successfully evicted, then the
+ * zbud page can be freed.
+ *
+ * Returns: 0 if page is successfully freed, otherwise -EINVAL if there are
+ * no pages to evict or an eviction handler is not registered, -EAGAIN if
+ * the retry limit was hit.
+ */
+int zbud_reclaim_page(struct zbud_pool *pool, unsigned int retries)
+{
+ int i, ret, freechunks;
+ struct zbud_header *zhdr;
+ unsigned long first_handle = 0, last_handle = 0;
+
+ spin_lock(&pool->lock);
+ if (!pool->ops || !pool->ops->evict || list_empty(&pool->lru) ||
+ retries == 0) {
+ spin_unlock(&pool->lock);
+ return -EINVAL;
+ }
+ for (i = 0; i < retries; i++) {
+ zhdr = list_tail_entry(&pool->lru, struct zbud_header, lru);
+ list_del(&zhdr->lru);
+ list_del(&zhdr->buddy);
+ /* Protect zbud page against free */
+ zhdr->under_reclaim = true;
+ /*
+ * We need encode the handles before unlocking, since we can
+ * race with free that will set (first|last)_chunks to 0
+ */
+ first_handle = 0;
+ last_handle = 0;
+ if (zhdr->first_chunks)
+ first_handle = encode_handle(zhdr, FIRST);
+ if (zhdr->last_chunks)
+ last_handle = encode_handle(zhdr, LAST);
+ spin_unlock(&pool->lock);
+
+ /* Issue the eviction callback(s) */
+ if (first_handle) {
+ ret = pool->ops->evict(pool, first_handle);
+ if (ret)
+ goto next;
+ }
+ if (last_handle) {
+ ret = pool->ops->evict(pool, last_handle);
+ if (ret)
+ goto next;
+ }
+next:
+ spin_lock(&pool->lock);
+ zhdr->under_reclaim = false;
+ if (zhdr->first_chunks == 0 && zhdr->last_chunks == 0) {
+ /*
+ * Both buddies are now free, free the zbud page and
+ * return success.
+ */
+ free_zbud_page(zhdr);
+ pool->pages_nr--;
+ spin_unlock(&pool->lock);
+ return 0;
+ } else if (zhdr->first_chunks == 0 ||
+ zhdr->last_chunks == 0) {
+ /* add to unbuddied list */
+ freechunks = num_free_chunks(zhdr);
+ list_add(&zhdr->buddy, &pool->unbuddied[freechunks]);
+ } else {
+ /* add to buddied list */
+ list_add(&zhdr->buddy, &pool->buddied);
+ }
+
+ /* add to beginning of LRU */
+ list_add(&zhdr->lru, &pool->lru);
+ }
+ spin_unlock(&pool->lock);
+ return -EAGAIN;
+}
+
+/**
+ * zbud_map() - maps the allocation associated with the given handle
+ * @pool: pool in which the allocation resides
+ * @handle: handle associated with the allocation to be mapped
+ *
+ * While trivial for zbud, the mapping functions for others allocators
+ * implementing this allocation API could have more complex information encoded
+ * in the handle and could create temporary mappings to make the data
+ * accessible to the user.
+ *
+ * Returns: a pointer to the mapped allocation
+ */
+void *zbud_map(struct zbud_pool *pool, unsigned long handle)
+{
+ return (void *)(handle);
+}
+
+/**
+ * zbud_unmap() - maps the allocation associated with the given handle
+ * @pool: pool in which the allocation resides
+ * @handle: handle associated with the allocation to be unmapped
+ */
+void zbud_unmap(struct zbud_pool *pool, unsigned long handle)
+{
+}
+
+/**
+ * zbud_get_pool_size() - gets the zbud pool size in pages
+ * @pool: pool whose size is being queried
+ *
+ * Returns: size in pages of the given pool. The pool lock need not be
+ * taken to access pages_nr.
+ */
+u64 zbud_get_pool_size(struct zbud_pool *pool)
+{
+ return pool->pages_nr;
+}
+
+static int __init init_zbud(void)
+{
+ /* Make sure the zbud header will fit in one chunk */
+ BUILD_BUG_ON(sizeof(struct zbud_header) > ZHDR_SIZE_ALIGNED);
+ pr_info("loaded\n");
+ return 0;
+}
+
+static void __exit exit_zbud(void)
+{
+ pr_info("unloaded\n");
+}
+
+module_init(init_zbud);
+module_exit(exit_zbud);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Seth Jennings <sjenning@linux.vnet.ibm.com>");
+MODULE_DESCRIPTION("Buddy Allocator for Compressed Pages");
diff --git a/mm/zswap.c b/mm/zswap.c
new file mode 100644
index 0000000..deda2b6
--- /dev/null
+++ b/mm/zswap.c
@@ -0,0 +1,943 @@
+/*
+ * zswap.c - zswap driver file
+ *
+ * zswap is a backend for frontswap that takes pages that are in the process
+ * of being swapped out and attempts to compress and store them in a
+ * RAM-based memory pool. This can result in a significant I/O reduction on
+ * the swap device and, in the case where decompressing from RAM is faster
+ * than reading from the swap device, can also improve workload performance.
+ *
+ * Copyright (C) 2012 Seth Jennings <sjenning@linux.vnet.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+*/
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/cpu.h>
+#include <linux/highmem.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <linux/atomic.h>
+#include <linux/frontswap.h>
+#include <linux/rbtree.h>
+#include <linux/swap.h>
+#include <linux/crypto.h>
+#include <linux/mempool.h>
+#include <linux/zbud.h>
+
+#include <linux/mm_types.h>
+#include <linux/page-flags.h>
+#include <linux/swapops.h>
+#include <linux/writeback.h>
+#include <linux/pagemap.h>
+
+/*********************************
+* statistics
+**********************************/
+/* Number of memory pages used by the compressed pool */
+static u64 zswap_pool_pages;
+/* The number of compressed pages currently stored in zswap */
+static atomic_t zswap_stored_pages = ATOMIC_INIT(0);
+
+/*
+ * The statistics below are not protected from concurrent access for
+ * performance reasons so they may not be a 100% accurate. However,
+ * they do provide useful information on roughly how many times a
+ * certain event is occurring.
+*/
+
+/* Pool limit was hit (see zswap_max_pool_percent) */
+static u64 zswap_pool_limit_hit;
+/* Pages written back when pool limit was reached */
+static u64 zswap_written_back_pages;
+/* Store failed due to a reclaim failure after pool limit was reached */
+static u64 zswap_reject_reclaim_fail;
+/* Compressed page was too big for the allocator to (optimally) store */
+static u64 zswap_reject_compress_poor;
+/* Store failed because underlying allocator could not get memory */
+static u64 zswap_reject_alloc_fail;
+/* Store failed because the entry metadata could not be allocated (rare) */
+static u64 zswap_reject_kmemcache_fail;
+/* Duplicate store was encountered (rare) */
+static u64 zswap_duplicate_entry;
+
+/*********************************
+* tunables
+**********************************/
+/* Enable/disable zswap (disabled by default, fixed at boot for now) */
+static bool zswap_enabled __read_mostly;
+module_param_named(enabled, zswap_enabled, bool, 0);
+
+/* Compressor to be used by zswap (fixed at boot for now) */
+#define ZSWAP_COMPRESSOR_DEFAULT "lzo"
+static char *zswap_compressor = ZSWAP_COMPRESSOR_DEFAULT;
+module_param_named(compressor, zswap_compressor, charp, 0);
+
+/* The maximum percentage of memory that the compressed pool can occupy */
+static unsigned int zswap_max_pool_percent = 20;
+module_param_named(max_pool_percent,
+ zswap_max_pool_percent, uint, 0644);
+
+/*********************************
+* compression functions
+**********************************/
+/* per-cpu compression transforms */
+static struct crypto_comp * __percpu *zswap_comp_pcpu_tfms;
+
+enum comp_op {
+ ZSWAP_COMPOP_COMPRESS,
+ ZSWAP_COMPOP_DECOMPRESS
+};
+
+static int zswap_comp_op(enum comp_op op, const u8 *src, unsigned int slen,
+ u8 *dst, unsigned int *dlen)
+{
+ struct crypto_comp *tfm;
+ int ret;
+
+ tfm = *per_cpu_ptr(zswap_comp_pcpu_tfms, get_cpu());
+ switch (op) {
+ case ZSWAP_COMPOP_COMPRESS:
+ ret = crypto_comp_compress(tfm, src, slen, dst, dlen);
+ break;
+ case ZSWAP_COMPOP_DECOMPRESS:
+ ret = crypto_comp_decompress(tfm, src, slen, dst, dlen);
+ break;
+ default:
+ ret = -EINVAL;
+ }
+
+ put_cpu();
+ return ret;
+}
+
+static int __init zswap_comp_init(void)
+{
+ if (!crypto_has_comp(zswap_compressor, 0, 0)) {
+ pr_info("%s compressor not available\n", zswap_compressor);
+ /* fall back to default compressor */
+ zswap_compressor = ZSWAP_COMPRESSOR_DEFAULT;
+ if (!crypto_has_comp(zswap_compressor, 0, 0))
+ /* can't even load the default compressor */
+ return -ENODEV;
+ }
+ pr_info("using %s compressor\n", zswap_compressor);
+
+ /* alloc percpu transforms */
+ zswap_comp_pcpu_tfms = alloc_percpu(struct crypto_comp *);
+ if (!zswap_comp_pcpu_tfms)
+ return -ENOMEM;
+ return 0;
+}
+
+static void zswap_comp_exit(void)
+{
+ /* free percpu transforms */
+ if (zswap_comp_pcpu_tfms)
+ free_percpu(zswap_comp_pcpu_tfms);
+}
+
+/*********************************
+* data structures
+**********************************/
+/*
+ * struct zswap_entry
+ *
+ * This structure contains the metadata for tracking a single compressed
+ * page within zswap.
+ *
+ * rbnode - links the entry into red-black tree for the appropriate swap type
+ * refcount - the number of outstanding reference to the entry. This is needed
+ * to protect against premature freeing of the entry by code
+ * concurent calls to load, invalidate, and writeback. The lock
+ * for the zswap_tree structure that contains the entry must
+ * be held while changing the refcount. Since the lock must
+ * be held, there is no reason to also make refcount atomic.
+ * offset - the swap offset for the entry. Index into the red-black tree.
+ * handle - zsmalloc allocation handle that stores the compressed page data
+ * length - the length in bytes of the compressed page data. Needed during
+ * decompression
+ */
+struct zswap_entry {
+ struct rb_node rbnode;
+ pgoff_t offset;
+ int refcount;
+ unsigned int length;
+ unsigned long handle;
+};
+
+struct zswap_header {
+ swp_entry_t swpentry;
+};
+
+/*
+ * The tree lock in the zswap_tree struct protects a few things:
+ * - the rbtree
+ * - the refcount field of each entry in the tree
+ */
+struct zswap_tree {
+ struct rb_root rbroot;
+ spinlock_t lock;
+ struct zbud_pool *pool;
+};
+
+static struct zswap_tree *zswap_trees[MAX_SWAPFILES];
+
+/*********************************
+* zswap entry functions
+**********************************/
+static struct kmem_cache *zswap_entry_cache;
+
+static int zswap_entry_cache_create(void)
+{
+ zswap_entry_cache = KMEM_CACHE(zswap_entry, 0);
+ return (zswap_entry_cache == NULL);
+}
+
+static void zswap_entry_cache_destory(void)
+{
+ kmem_cache_destroy(zswap_entry_cache);
+}
+
+static struct zswap_entry *zswap_entry_cache_alloc(gfp_t gfp)
+{
+ struct zswap_entry *entry;
+ entry = kmem_cache_alloc(zswap_entry_cache, gfp);
+ if (!entry)
+ return NULL;
+ entry->refcount = 1;
+ return entry;
+}
+
+static void zswap_entry_cache_free(struct zswap_entry *entry)
+{
+ kmem_cache_free(zswap_entry_cache, entry);
+}
+
+/* caller must hold the tree lock */
+static void zswap_entry_get(struct zswap_entry *entry)
+{
+ entry->refcount++;
+}
+
+/* caller must hold the tree lock */
+static int zswap_entry_put(struct zswap_entry *entry)
+{
+ entry->refcount--;
+ return entry->refcount;
+}
+
+/*********************************
+* rbtree functions
+**********************************/
+static struct zswap_entry *zswap_rb_search(struct rb_root *root, pgoff_t offset)
+{
+ struct rb_node *node = root->rb_node;
+ struct zswap_entry *entry;
+
+ while (node) {
+ entry = rb_entry(node, struct zswap_entry, rbnode);
+ if (entry->offset > offset)
+ node = node->rb_left;
+ else if (entry->offset < offset)
+ node = node->rb_right;
+ else
+ return entry;
+ }
+ return NULL;
+}
+
+/*
+ * In the case that a entry with the same offset is found, a pointer to
+ * the existing entry is stored in dupentry and the function returns -EEXIST
+ */
+static int zswap_rb_insert(struct rb_root *root, struct zswap_entry *entry,
+ struct zswap_entry **dupentry)
+{
+ struct rb_node **link = &root->rb_node, *parent = NULL;
+ struct zswap_entry *myentry;
+
+ while (*link) {
+ parent = *link;
+ myentry = rb_entry(parent, struct zswap_entry, rbnode);
+ if (myentry->offset > entry->offset)
+ link = &(*link)->rb_left;
+ else if (myentry->offset < entry->offset)
+ link = &(*link)->rb_right;
+ else {
+ *dupentry = myentry;
+ return -EEXIST;
+ }
+ }
+ rb_link_node(&entry->rbnode, parent, link);
+ rb_insert_color(&entry->rbnode, root);
+ return 0;
+}
+
+/*********************************
+* per-cpu code
+**********************************/
+static DEFINE_PER_CPU(u8 *, zswap_dstmem);
+
+static int __zswap_cpu_notifier(unsigned long action, unsigned long cpu)
+{
+ struct crypto_comp *tfm;
+ u8 *dst;
+
+ switch (action) {
+ case CPU_UP_PREPARE:
+ tfm = crypto_alloc_comp(zswap_compressor, 0, 0);
+ if (IS_ERR(tfm)) {
+ pr_err("can't allocate compressor transform\n");
+ return NOTIFY_BAD;
+ }
+ *per_cpu_ptr(zswap_comp_pcpu_tfms, cpu) = tfm;
+ dst = kmalloc(PAGE_SIZE * 2, GFP_KERNEL);
+ if (!dst) {
+ pr_err("can't allocate compressor buffer\n");
+ crypto_free_comp(tfm);
+ *per_cpu_ptr(zswap_comp_pcpu_tfms, cpu) = NULL;
+ return NOTIFY_BAD;
+ }
+ per_cpu(zswap_dstmem, cpu) = dst;
+ break;
+ case CPU_DEAD:
+ case CPU_UP_CANCELED:
+ tfm = *per_cpu_ptr(zswap_comp_pcpu_tfms, cpu);
+ if (tfm) {
+ crypto_free_comp(tfm);
+ *per_cpu_ptr(zswap_comp_pcpu_tfms, cpu) = NULL;
+ }
+ dst = per_cpu(zswap_dstmem, cpu);
+ kfree(dst);
+ per_cpu(zswap_dstmem, cpu) = NULL;
+ break;
+ default:
+ break;
+ }
+ return NOTIFY_OK;
+}
+
+static int zswap_cpu_notifier(struct notifier_block *nb,
+ unsigned long action, void *pcpu)
+{
+ unsigned long cpu = (unsigned long)pcpu;
+ return __zswap_cpu_notifier(action, cpu);
+}
+
+static struct notifier_block zswap_cpu_notifier_block = {
+ .notifier_call = zswap_cpu_notifier
+};
+
+static int zswap_cpu_init(void)
+{
+ unsigned long cpu;
+
+ get_online_cpus();
+ for_each_online_cpu(cpu)
+ if (__zswap_cpu_notifier(CPU_UP_PREPARE, cpu) != NOTIFY_OK)
+ goto cleanup;
+ register_cpu_notifier(&zswap_cpu_notifier_block);
+ put_online_cpus();
+ return 0;
+
+cleanup:
+ for_each_online_cpu(cpu)
+ __zswap_cpu_notifier(CPU_UP_CANCELED, cpu);
+ put_online_cpus();
+ return -ENOMEM;
+}
+
+/*********************************
+* helpers
+**********************************/
+static bool zswap_is_full(void)
+{
+ return (totalram_pages * zswap_max_pool_percent / 100 <
+ zswap_pool_pages);
+}
+
+/*
+ * Carries out the common pattern of freeing and entry's zsmalloc allocation,
+ * freeing the entry itself, and decrementing the number of stored pages.
+ */
+static void zswap_free_entry(struct zswap_tree *tree, struct zswap_entry *entry)
+{
+ zbud_free(tree->pool, entry->handle);
+ zswap_entry_cache_free(entry);
+ atomic_dec(&zswap_stored_pages);
+ zswap_pool_pages = zbud_get_pool_size(tree->pool);
+}
+
+/*********************************
+* writeback code
+**********************************/
+/* return enum for zswap_get_swap_cache_page */
+enum zswap_get_swap_ret {
+ ZSWAP_SWAPCACHE_NEW,
+ ZSWAP_SWAPCACHE_EXIST,
+ ZSWAP_SWAPCACHE_NOMEM
+};
+
+/*
+ * zswap_get_swap_cache_page
+ *
+ * This is an adaption of read_swap_cache_async()
+ *
+ * This function tries to find a page with the given swap entry
+ * in the swapper_space address space (the swap cache). If the page
+ * is found, it is returned in retpage. Otherwise, a page is allocated,
+ * added to the swap cache, and returned in retpage.
+ *
+ * If success, the swap cache page is returned in retpage
+ * Returns 0 if page was already in the swap cache, page is not locked
+ * Returns 1 if the new page needs to be populated, page is locked
+ * Returns <0 on error
+ */
+static int zswap_get_swap_cache_page(swp_entry_t entry,
+ struct page **retpage)
+{
+ struct page *found_page, *new_page = NULL;
+ struct address_space *swapper_space = &swapper_spaces[swp_type(entry)];
+ int err;
+
+ *retpage = NULL;
+ do {
+ /*
+ * First check the swap cache. Since this is normally
+ * called after lookup_swap_cache() failed, re-calling
+ * that would confuse statistics.
+ */
+ found_page = find_get_page(swapper_space, entry.val);
+ if (found_page)
+ break;
+
+ /*
+ * Get a new page to read into from swap.
+ */
+ if (!new_page) {
+ new_page = alloc_page(GFP_KERNEL);
+ if (!new_page)
+ break; /* Out of memory */
+ }
+
+ /*
+ * call radix_tree_preload() while we can wait.
+ */
+ err = radix_tree_preload(GFP_KERNEL);
+ if (err)
+ break;
+
+ /*
+ * Swap entry may have been freed since our caller observed it.
+ */
+ err = swapcache_prepare(entry);
+ if (err == -EEXIST) { /* seems racy */
+ radix_tree_preload_end();
+ continue;
+ }
+ if (err) { /* swp entry is obsolete ? */
+ radix_tree_preload_end();
+ break;
+ }
+
+ /* May fail (-ENOMEM) if radix-tree node allocation failed. */
+ __set_page_locked(new_page);
+ SetPageSwapBacked(new_page);
+ err = __add_to_swap_cache(new_page, entry);
+ if (likely(!err)) {
+ radix_tree_preload_end();
+ lru_cache_add_anon(new_page);
+ *retpage = new_page;
+ return ZSWAP_SWAPCACHE_NEW;
+ }
+ radix_tree_preload_end();
+ ClearPageSwapBacked(new_page);
+ __clear_page_locked(new_page);
+ /*
+ * add_to_swap_cache() doesn't return -EEXIST, so we can safely
+ * clear SWAP_HAS_CACHE flag.
+ */
+ swapcache_free(entry, NULL);
+ } while (err != -ENOMEM);
+
+ if (new_page)
+ page_cache_release(new_page);
+ if (!found_page)
+ return ZSWAP_SWAPCACHE_NOMEM;
+ *retpage = found_page;
+ return ZSWAP_SWAPCACHE_EXIST;
+}
+
+/*
+ * Attempts to free an entry by adding a page to the swap cache,
+ * decompressing the entry data into the page, and issuing a
+ * bio write to write the page back to the swap device.
+ *
+ * This can be thought of as a "resumed writeback" of the page
+ * to the swap device. We are basically resuming the same swap
+ * writeback path that was intercepted with the frontswap_store()
+ * in the first place. After the page has been decompressed into
+ * the swap cache, the compressed version stored by zswap can be
+ * freed.
+ */
+static int zswap_writeback_entry(struct zbud_pool *pool, unsigned long handle)
+{
+ struct zswap_header *zhdr;
+ swp_entry_t swpentry;
+ struct zswap_tree *tree;
+ pgoff_t offset;
+ struct zswap_entry *entry;
+ struct page *page;
+ u8 *src, *dst;
+ unsigned int dlen;
+ int ret, refcount;
+ struct writeback_control wbc = {
+ .sync_mode = WB_SYNC_NONE,
+ };
+
+ /* extract swpentry from data */
+ zhdr = zbud_map(pool, handle);
+ swpentry = zhdr->swpentry; /* here */
+ zbud_unmap(pool, handle);
+ tree = zswap_trees[swp_type(swpentry)];
+ offset = swp_offset(swpentry);
+ BUG_ON(pool != tree->pool);
+
+ /* find and ref zswap entry */
+ spin_lock(&tree->lock);
+ entry = zswap_rb_search(&tree->rbroot, offset);
+ if (!entry) {
+ /* entry was invalidated */
+ spin_unlock(&tree->lock);
+ return 0;
+ }
+ zswap_entry_get(entry);
+ spin_unlock(&tree->lock);
+ BUG_ON(offset != entry->offset);
+
+ /* try to allocate swap cache page */
+ switch (zswap_get_swap_cache_page(swpentry, &page)) {
+ case ZSWAP_SWAPCACHE_NOMEM: /* no memory */
+ ret = -ENOMEM;
+ goto fail;
+
+ case ZSWAP_SWAPCACHE_EXIST: /* page is unlocked */
+ /* page is already in the swap cache, ignore for now */
+ page_cache_release(page);
+ ret = -EEXIST;
+ goto fail;
+
+ case ZSWAP_SWAPCACHE_NEW: /* page is locked */
+ /* decompress */
+ dlen = PAGE_SIZE;
+ src = (u8 *)zbud_map(tree->pool, entry->handle) +
+ sizeof(struct zswap_header);
+ dst = kmap_atomic(page);
+ ret = zswap_comp_op(ZSWAP_COMPOP_DECOMPRESS, src,
+ entry->length, dst, &dlen);
+ kunmap_atomic(dst);
+ zbud_unmap(tree->pool, entry->handle);
+ BUG_ON(ret);
+ BUG_ON(dlen != PAGE_SIZE);
+
+ /* page is up to date */
+ SetPageUptodate(page);
+ }
+
+ /* start writeback */
+ __swap_writepage(page, &wbc, end_swap_bio_write);
+ page_cache_release(page);
+ zswap_written_back_pages++;
+
+ spin_lock(&tree->lock);
+
+ /* drop local reference */
+ zswap_entry_put(entry);
+ /* drop the initial reference from entry creation */
+ refcount = zswap_entry_put(entry);
+
+ /*
+ * There are three possible values for refcount here:
+ * (1) refcount is 1, load is in progress, unlink from rbtree,
+ * load will free
+ * (2) refcount is 0, (normal case) entry is valid,
+ * remove from rbtree and free entry
+ * (3) refcount is -1, invalidate happened during writeback,
+ * free entry
+ */
+ if (refcount >= 0) {
+ /* no invalidate yet, remove from rbtree */
+ rb_erase(&entry->rbnode, &tree->rbroot);
+ }
+ spin_unlock(&tree->lock);
+ if (refcount <= 0) {
+ /* free the entry */
+ zswap_free_entry(tree, entry);
+ return 0;
+ }
+ return -EAGAIN;
+
+fail:
+ spin_lock(&tree->lock);
+ zswap_entry_put(entry);
+ spin_unlock(&tree->lock);
+ return ret;
+}
+
+/*********************************
+* frontswap hooks
+**********************************/
+/* attempts to compress and store an single page */
+static int zswap_frontswap_store(unsigned type, pgoff_t offset,
+ struct page *page)
+{
+ struct zswap_tree *tree = zswap_trees[type];
+ struct zswap_entry *entry, *dupentry;
+ int ret;
+ unsigned int dlen = PAGE_SIZE, len;
+ unsigned long handle;
+ char *buf;
+ u8 *src, *dst;
+ struct zswap_header *zhdr;
+
+ if (!tree) {
+ ret = -ENODEV;
+ goto reject;
+ }
+
+ /* reclaim space if needed */
+ if (zswap_is_full()) {
+ zswap_pool_limit_hit++;
+ if (zbud_reclaim_page(tree->pool, 8)) {
+ zswap_reject_reclaim_fail++;
+ ret = -ENOMEM;
+ goto reject;
+ }
+ }
+
+ /* allocate entry */
+ entry = zswap_entry_cache_alloc(GFP_KERNEL);
+ if (!entry) {
+ zswap_reject_kmemcache_fail++;
+ ret = -ENOMEM;
+ goto reject;
+ }
+
+ /* compress */
+ dst = get_cpu_var(zswap_dstmem);
+ src = kmap_atomic(page);
+ ret = zswap_comp_op(ZSWAP_COMPOP_COMPRESS, src, PAGE_SIZE, dst, &dlen);
+ kunmap_atomic(src);
+ if (ret) {
+ ret = -EINVAL;
+ goto freepage;
+ }
+
+ /* store */
+ len = dlen + sizeof(struct zswap_header);
+ ret = zbud_alloc(tree->pool, len, __GFP_NORETRY | __GFP_NOWARN,
+ &handle);
+ if (ret == -ENOSPC) {
+ zswap_reject_compress_poor++;
+ goto freepage;
+ }
+ if (ret) {
+ zswap_reject_alloc_fail++;
+ goto freepage;
+ }
+ zhdr = zbud_map(tree->pool, handle);
+ zhdr->swpentry = swp_entry(type, offset);
+ buf = (u8 *)(zhdr + 1);
+ memcpy(buf, dst, dlen);
+ zbud_unmap(tree->pool, handle);
+ put_cpu_var(zswap_dstmem);
+
+ /* populate entry */
+ entry->offset = offset;
+ entry->handle = handle;
+ entry->length = dlen;
+
+ /* map */
+ spin_lock(&tree->lock);
+ do {
+ ret = zswap_rb_insert(&tree->rbroot, entry, &dupentry);
+ if (ret == -EEXIST) {
+ zswap_duplicate_entry++;
+ /* remove from rbtree */
+ rb_erase(&dupentry->rbnode, &tree->rbroot);
+ if (!zswap_entry_put(dupentry)) {
+ /* free */
+ zswap_free_entry(tree, dupentry);
+ }
+ }
+ } while (ret == -EEXIST);
+ spin_unlock(&tree->lock);
+
+ /* update stats */
+ atomic_inc(&zswap_stored_pages);
+ zswap_pool_pages = zbud_get_pool_size(tree->pool);
+
+ return 0;
+
+freepage:
+ put_cpu_var(zswap_dstmem);
+ zswap_entry_cache_free(entry);
+reject:
+ return ret;
+}
+
+/*
+ * returns 0 if the page was successfully decompressed
+ * return -1 on entry not found or error
+*/
+static int zswap_frontswap_load(unsigned type, pgoff_t offset,
+ struct page *page)
+{
+ struct zswap_tree *tree = zswap_trees[type];
+ struct zswap_entry *entry;
+ u8 *src, *dst;
+ unsigned int dlen;
+ int refcount, ret;
+
+ /* find */
+ spin_lock(&tree->lock);
+ entry = zswap_rb_search(&tree->rbroot, offset);
+ if (!entry) {
+ /* entry was written back */
+ spin_unlock(&tree->lock);
+ return -1;
+ }
+ zswap_entry_get(entry);
+ spin_unlock(&tree->lock);
+
+ /* decompress */
+ dlen = PAGE_SIZE;
+ src = (u8 *)zbud_map(tree->pool, entry->handle) +
+ sizeof(struct zswap_header);
+ dst = kmap_atomic(page);
+ ret = zswap_comp_op(ZSWAP_COMPOP_DECOMPRESS, src, entry->length,
+ dst, &dlen);
+ kunmap_atomic(dst);
+ zbud_unmap(tree->pool, entry->handle);
+ BUG_ON(ret);
+
+ spin_lock(&tree->lock);
+ refcount = zswap_entry_put(entry);
+ if (likely(refcount)) {
+ spin_unlock(&tree->lock);
+ return 0;
+ }
+ spin_unlock(&tree->lock);
+
+ /*
+ * We don't have to unlink from the rbtree because
+ * zswap_writeback_entry() or zswap_frontswap_invalidate page()
+ * has already done this for us if we are the last reference.
+ */
+ /* free */
+
+ zswap_free_entry(tree, entry);
+
+ return 0;
+}
+
+/* frees an entry in zswap */
+static void zswap_frontswap_invalidate_page(unsigned type, pgoff_t offset)
+{
+ struct zswap_tree *tree = zswap_trees[type];
+ struct zswap_entry *entry;
+ int refcount;
+
+ /* find */
+ spin_lock(&tree->lock);
+ entry = zswap_rb_search(&tree->rbroot, offset);
+ if (!entry) {
+ /* entry was written back */
+ spin_unlock(&tree->lock);
+ return;
+ }
+
+ /* remove from rbtree */
+ rb_erase(&entry->rbnode, &tree->rbroot);
+
+ /* drop the initial reference from entry creation */
+ refcount = zswap_entry_put(entry);
+
+ spin_unlock(&tree->lock);
+
+ if (refcount) {
+ /* writeback in progress, writeback will free */
+ return;
+ }
+
+ /* free */
+ zswap_free_entry(tree, entry);
+}
+
+/* frees all zswap entries for the given swap type */
+static void zswap_frontswap_invalidate_area(unsigned type)
+{
+ struct zswap_tree *tree = zswap_trees[type];
+ struct rb_node *node;
+ struct zswap_entry *entry;
+
+ if (!tree)
+ return;
+
+ /* walk the tree and free everything */
+ spin_lock(&tree->lock);
+ /*
+ * TODO: Even though this code should not be executed because
+ * the try_to_unuse() in swapoff should have emptied the tree,
+ * it is very wasteful to rebalance the tree after every
+ * removal when we are freeing the whole tree.
+ *
+ * If post-order traversal code is ever added to the rbtree
+ * implementation, it should be used here.
+ */
+ while ((node = rb_first(&tree->rbroot))) {
+ entry = rb_entry(node, struct zswap_entry, rbnode);
+ rb_erase(&entry->rbnode, &tree->rbroot);
+ zbud_free(tree->pool, entry->handle);
+ zswap_entry_cache_free(entry);
+ atomic_dec(&zswap_stored_pages);
+ }
+ tree->rbroot = RB_ROOT;
+ spin_unlock(&tree->lock);
+}
+
+static struct zbud_ops zswap_zbud_ops = {
+ .evict = zswap_writeback_entry
+};
+
+static void zswap_frontswap_init(unsigned type)
+{
+ struct zswap_tree *tree;
+
+ tree = kzalloc(sizeof(struct zswap_tree), GFP_KERNEL);
+ if (!tree)
+ goto err;
+ tree->pool = zbud_create_pool(GFP_KERNEL, &zswap_zbud_ops);
+ if (!tree->pool)
+ goto freetree;
+ tree->rbroot = RB_ROOT;
+ spin_lock_init(&tree->lock);
+ zswap_trees[type] = tree;
+ return;
+
+freetree:
+ kfree(tree);
+err:
+ pr_err("alloc failed, zswap disabled for swap type %d\n", type);
+}
+
+static struct frontswap_ops zswap_frontswap_ops = {
+ .store = zswap_frontswap_store,
+ .load = zswap_frontswap_load,
+ .invalidate_page = zswap_frontswap_invalidate_page,
+ .invalidate_area = zswap_frontswap_invalidate_area,
+ .init = zswap_frontswap_init
+};
+
+/*********************************
+* debugfs functions
+**********************************/
+#ifdef CONFIG_DEBUG_FS
+#include <linux/debugfs.h>
+
+static struct dentry *zswap_debugfs_root;
+
+static int __init zswap_debugfs_init(void)
+{
+ if (!debugfs_initialized())
+ return -ENODEV;
+
+ zswap_debugfs_root = debugfs_create_dir("zswap", NULL);
+ if (!zswap_debugfs_root)
+ return -ENOMEM;
+
+ debugfs_create_u64("pool_limit_hit", S_IRUGO,
+ zswap_debugfs_root, &zswap_pool_limit_hit);
+ debugfs_create_u64("reject_reclaim_fail", S_IRUGO,
+ zswap_debugfs_root, &zswap_reject_reclaim_fail);
+ debugfs_create_u64("reject_alloc_fail", S_IRUGO,
+ zswap_debugfs_root, &zswap_reject_alloc_fail);
+ debugfs_create_u64("reject_kmemcache_fail", S_IRUGO,
+ zswap_debugfs_root, &zswap_reject_kmemcache_fail);
+ debugfs_create_u64("reject_compress_poor", S_IRUGO,
+ zswap_debugfs_root, &zswap_reject_compress_poor);
+ debugfs_create_u64("written_back_pages", S_IRUGO,
+ zswap_debugfs_root, &zswap_written_back_pages);
+ debugfs_create_u64("duplicate_entry", S_IRUGO,
+ zswap_debugfs_root, &zswap_duplicate_entry);
+ debugfs_create_u64("pool_pages", S_IRUGO,
+ zswap_debugfs_root, &zswap_pool_pages);
+ debugfs_create_atomic_t("stored_pages", S_IRUGO,
+ zswap_debugfs_root, &zswap_stored_pages);
+
+ return 0;
+}
+
+static void __exit zswap_debugfs_exit(void)
+{
+ debugfs_remove_recursive(zswap_debugfs_root);
+}
+#else
+static int __init zswap_debugfs_init(void)
+{
+ return 0;
+}
+
+static void __exit zswap_debugfs_exit(void) { }
+#endif
+
+/*********************************
+* module init and exit
+**********************************/
+static int __init init_zswap(void)
+{
+ if (!zswap_enabled)
+ return 0;
+
+ pr_info("loading zswap\n");
+ if (zswap_entry_cache_create()) {
+ pr_err("entry cache creation failed\n");
+ goto error;
+ }
+ if (zswap_comp_init()) {
+ pr_err("compressor initialization failed\n");
+ goto compfail;
+ }
+ if (zswap_cpu_init()) {
+ pr_err("per-cpu initialization failed\n");
+ goto pcpufail;
+ }
+ frontswap_register_ops(&zswap_frontswap_ops);
+ if (zswap_debugfs_init())
+ pr_warn("debugfs initialization failed\n");
+ return 0;
+pcpufail:
+ zswap_comp_exit();
+compfail:
+ zswap_entry_cache_destory();
+error:
+ return -ENOMEM;
+}
+/* must be late so crypto has time to come up */
+late_initcall(init_zswap);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Seth Jennings <sjenning@linux.vnet.ibm.com>");
+MODULE_DESCRIPTION("Compressed cache for swap pages");