| /* memcontrol.c - Memory Controller |
| * |
| * Copyright IBM Corporation, 2007 |
| * Author Balbir Singh <balbir@linux.vnet.ibm.com> |
| * |
| * Copyright 2007 OpenVZ SWsoft Inc |
| * Author: Pavel Emelianov <xemul@openvz.org> |
| * |
| * 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. |
| */ |
| |
| #include <linux/res_counter.h> |
| #include <linux/memcontrol.h> |
| #include <linux/cgroup.h> |
| #include <linux/mm.h> |
| #include <linux/pagemap.h> |
| #include <linux/smp.h> |
| #include <linux/page-flags.h> |
| #include <linux/backing-dev.h> |
| #include <linux/bit_spinlock.h> |
| #include <linux/rcupdate.h> |
| #include <linux/mutex.h> |
| #include <linux/slab.h> |
| #include <linux/swap.h> |
| #include <linux/spinlock.h> |
| #include <linux/fs.h> |
| #include <linux/seq_file.h> |
| #include <linux/vmalloc.h> |
| #include <linux/mm_inline.h> |
| #include <linux/page_cgroup.h> |
| #include "internal.h" |
| |
| #include <asm/uaccess.h> |
| |
| struct cgroup_subsys mem_cgroup_subsys __read_mostly; |
| #define MEM_CGROUP_RECLAIM_RETRIES 5 |
| |
| #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
| /* Turned on only when memory cgroup is enabled && really_do_swap_account = 0 */ |
| int do_swap_account __read_mostly; |
| static int really_do_swap_account __initdata = 1; /* for remember boot option*/ |
| #else |
| #define do_swap_account (0) |
| #endif |
| |
| static DEFINE_MUTEX(memcg_tasklist); /* can be hold under cgroup_mutex */ |
| |
| /* |
| * Statistics for memory cgroup. |
| */ |
| enum mem_cgroup_stat_index { |
| /* |
| * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss. |
| */ |
| MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */ |
| MEM_CGROUP_STAT_RSS, /* # of pages charged as rss */ |
| MEM_CGROUP_STAT_PGPGIN_COUNT, /* # of pages paged in */ |
| MEM_CGROUP_STAT_PGPGOUT_COUNT, /* # of pages paged out */ |
| |
| MEM_CGROUP_STAT_NSTATS, |
| }; |
| |
| struct mem_cgroup_stat_cpu { |
| s64 count[MEM_CGROUP_STAT_NSTATS]; |
| } ____cacheline_aligned_in_smp; |
| |
| struct mem_cgroup_stat { |
| struct mem_cgroup_stat_cpu cpustat[0]; |
| }; |
| |
| /* |
| * For accounting under irq disable, no need for increment preempt count. |
| */ |
| static inline void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat_cpu *stat, |
| enum mem_cgroup_stat_index idx, int val) |
| { |
| stat->count[idx] += val; |
| } |
| |
| static s64 mem_cgroup_read_stat(struct mem_cgroup_stat *stat, |
| enum mem_cgroup_stat_index idx) |
| { |
| int cpu; |
| s64 ret = 0; |
| for_each_possible_cpu(cpu) |
| ret += stat->cpustat[cpu].count[idx]; |
| return ret; |
| } |
| |
| /* |
| * per-zone information in memory controller. |
| */ |
| struct mem_cgroup_per_zone { |
| /* |
| * spin_lock to protect the per cgroup LRU |
| */ |
| struct list_head lists[NR_LRU_LISTS]; |
| unsigned long count[NR_LRU_LISTS]; |
| |
| struct zone_reclaim_stat reclaim_stat; |
| }; |
| /* Macro for accessing counter */ |
| #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)]) |
| |
| struct mem_cgroup_per_node { |
| struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES]; |
| }; |
| |
| struct mem_cgroup_lru_info { |
| struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES]; |
| }; |
| |
| /* |
| * The memory controller data structure. The memory controller controls both |
| * page cache and RSS per cgroup. We would eventually like to provide |
| * statistics based on the statistics developed by Rik Van Riel for clock-pro, |
| * to help the administrator determine what knobs to tune. |
| * |
| * TODO: Add a water mark for the memory controller. Reclaim will begin when |
| * we hit the water mark. May be even add a low water mark, such that |
| * no reclaim occurs from a cgroup at it's low water mark, this is |
| * a feature that will be implemented much later in the future. |
| */ |
| struct mem_cgroup { |
| struct cgroup_subsys_state css; |
| /* |
| * the counter to account for memory usage |
| */ |
| struct res_counter res; |
| /* |
| * the counter to account for mem+swap usage. |
| */ |
| struct res_counter memsw; |
| /* |
| * Per cgroup active and inactive list, similar to the |
| * per zone LRU lists. |
| */ |
| struct mem_cgroup_lru_info info; |
| |
| /* |
| protect against reclaim related member. |
| */ |
| spinlock_t reclaim_param_lock; |
| |
| int prev_priority; /* for recording reclaim priority */ |
| |
| /* |
| * While reclaiming in a hiearchy, we cache the last child we |
| * reclaimed from. Protected by hierarchy_mutex |
| */ |
| struct mem_cgroup *last_scanned_child; |
| /* |
| * Should the accounting and control be hierarchical, per subtree? |
| */ |
| bool use_hierarchy; |
| unsigned long last_oom_jiffies; |
| atomic_t refcnt; |
| |
| unsigned int swappiness; |
| |
| /* |
| * statistics. This must be placed at the end of memcg. |
| */ |
| struct mem_cgroup_stat stat; |
| }; |
| |
| enum charge_type { |
| MEM_CGROUP_CHARGE_TYPE_CACHE = 0, |
| MEM_CGROUP_CHARGE_TYPE_MAPPED, |
| MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */ |
| MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */ |
| MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */ |
| NR_CHARGE_TYPE, |
| }; |
| |
| /* only for here (for easy reading.) */ |
| #define PCGF_CACHE (1UL << PCG_CACHE) |
| #define PCGF_USED (1UL << PCG_USED) |
| #define PCGF_LOCK (1UL << PCG_LOCK) |
| static const unsigned long |
| pcg_default_flags[NR_CHARGE_TYPE] = { |
| PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* File Cache */ |
| PCGF_USED | PCGF_LOCK, /* Anon */ |
| PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* Shmem */ |
| 0, /* FORCE */ |
| }; |
| |
| /* for encoding cft->private value on file */ |
| #define _MEM (0) |
| #define _MEMSWAP (1) |
| #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val)) |
| #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff) |
| #define MEMFILE_ATTR(val) ((val) & 0xffff) |
| |
| static void mem_cgroup_get(struct mem_cgroup *mem); |
| static void mem_cgroup_put(struct mem_cgroup *mem); |
| |
| static void mem_cgroup_charge_statistics(struct mem_cgroup *mem, |
| struct page_cgroup *pc, |
| bool charge) |
| { |
| int val = (charge)? 1 : -1; |
| struct mem_cgroup_stat *stat = &mem->stat; |
| struct mem_cgroup_stat_cpu *cpustat; |
| int cpu = get_cpu(); |
| |
| cpustat = &stat->cpustat[cpu]; |
| if (PageCgroupCache(pc)) |
| __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_CACHE, val); |
| else |
| __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_RSS, val); |
| |
| if (charge) |
| __mem_cgroup_stat_add_safe(cpustat, |
| MEM_CGROUP_STAT_PGPGIN_COUNT, 1); |
| else |
| __mem_cgroup_stat_add_safe(cpustat, |
| MEM_CGROUP_STAT_PGPGOUT_COUNT, 1); |
| put_cpu(); |
| } |
| |
| static struct mem_cgroup_per_zone * |
| mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid) |
| { |
| return &mem->info.nodeinfo[nid]->zoneinfo[zid]; |
| } |
| |
| static struct mem_cgroup_per_zone * |
| page_cgroup_zoneinfo(struct page_cgroup *pc) |
| { |
| struct mem_cgroup *mem = pc->mem_cgroup; |
| int nid = page_cgroup_nid(pc); |
| int zid = page_cgroup_zid(pc); |
| |
| if (!mem) |
| return NULL; |
| |
| return mem_cgroup_zoneinfo(mem, nid, zid); |
| } |
| |
| static unsigned long mem_cgroup_get_all_zonestat(struct mem_cgroup *mem, |
| enum lru_list idx) |
| { |
| int nid, zid; |
| struct mem_cgroup_per_zone *mz; |
| u64 total = 0; |
| |
| for_each_online_node(nid) |
| for (zid = 0; zid < MAX_NR_ZONES; zid++) { |
| mz = mem_cgroup_zoneinfo(mem, nid, zid); |
| total += MEM_CGROUP_ZSTAT(mz, idx); |
| } |
| return total; |
| } |
| |
| static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont) |
| { |
| return container_of(cgroup_subsys_state(cont, |
| mem_cgroup_subsys_id), struct mem_cgroup, |
| css); |
| } |
| |
| struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) |
| { |
| /* |
| * mm_update_next_owner() may clear mm->owner to NULL |
| * if it races with swapoff, page migration, etc. |
| * So this can be called with p == NULL. |
| */ |
| if (unlikely(!p)) |
| return NULL; |
| |
| return container_of(task_subsys_state(p, mem_cgroup_subsys_id), |
| struct mem_cgroup, css); |
| } |
| |
| static struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm) |
| { |
| struct mem_cgroup *mem = NULL; |
| /* |
| * Because we have no locks, mm->owner's may be being moved to other |
| * cgroup. We use css_tryget() here even if this looks |
| * pessimistic (rather than adding locks here). |
| */ |
| rcu_read_lock(); |
| do { |
| mem = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
| if (unlikely(!mem)) |
| break; |
| } while (!css_tryget(&mem->css)); |
| rcu_read_unlock(); |
| return mem; |
| } |
| |
| static bool mem_cgroup_is_obsolete(struct mem_cgroup *mem) |
| { |
| if (!mem) |
| return true; |
| return css_is_removed(&mem->css); |
| } |
| |
| /* |
| * Following LRU functions are allowed to be used without PCG_LOCK. |
| * Operations are called by routine of global LRU independently from memcg. |
| * What we have to take care of here is validness of pc->mem_cgroup. |
| * |
| * Changes to pc->mem_cgroup happens when |
| * 1. charge |
| * 2. moving account |
| * In typical case, "charge" is done before add-to-lru. Exception is SwapCache. |
| * It is added to LRU before charge. |
| * If PCG_USED bit is not set, page_cgroup is not added to this private LRU. |
| * When moving account, the page is not on LRU. It's isolated. |
| */ |
| |
| void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru) |
| { |
| struct page_cgroup *pc; |
| struct mem_cgroup *mem; |
| struct mem_cgroup_per_zone *mz; |
| |
| if (mem_cgroup_disabled()) |
| return; |
| pc = lookup_page_cgroup(page); |
| /* can happen while we handle swapcache. */ |
| if (list_empty(&pc->lru) || !pc->mem_cgroup) |
| return; |
| /* |
| * We don't check PCG_USED bit. It's cleared when the "page" is finally |
| * removed from global LRU. |
| */ |
| mz = page_cgroup_zoneinfo(pc); |
| mem = pc->mem_cgroup; |
| MEM_CGROUP_ZSTAT(mz, lru) -= 1; |
| list_del_init(&pc->lru); |
| return; |
| } |
| |
| void mem_cgroup_del_lru(struct page *page) |
| { |
| mem_cgroup_del_lru_list(page, page_lru(page)); |
| } |
| |
| void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru) |
| { |
| struct mem_cgroup_per_zone *mz; |
| struct page_cgroup *pc; |
| |
| if (mem_cgroup_disabled()) |
| return; |
| |
| pc = lookup_page_cgroup(page); |
| /* |
| * Used bit is set without atomic ops but after smp_wmb(). |
| * For making pc->mem_cgroup visible, insert smp_rmb() here. |
| */ |
| smp_rmb(); |
| /* unused page is not rotated. */ |
| if (!PageCgroupUsed(pc)) |
| return; |
| mz = page_cgroup_zoneinfo(pc); |
| list_move(&pc->lru, &mz->lists[lru]); |
| } |
| |
| void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru) |
| { |
| struct page_cgroup *pc; |
| struct mem_cgroup_per_zone *mz; |
| |
| if (mem_cgroup_disabled()) |
| return; |
| pc = lookup_page_cgroup(page); |
| /* |
| * Used bit is set without atomic ops but after smp_wmb(). |
| * For making pc->mem_cgroup visible, insert smp_rmb() here. |
| */ |
| smp_rmb(); |
| if (!PageCgroupUsed(pc)) |
| return; |
| |
| mz = page_cgroup_zoneinfo(pc); |
| MEM_CGROUP_ZSTAT(mz, lru) += 1; |
| list_add(&pc->lru, &mz->lists[lru]); |
| } |
| |
| /* |
| * At handling SwapCache, pc->mem_cgroup may be changed while it's linked to |
| * lru because the page may.be reused after it's fully uncharged (because of |
| * SwapCache behavior).To handle that, unlink page_cgroup from LRU when charge |
| * it again. This function is only used to charge SwapCache. It's done under |
| * lock_page and expected that zone->lru_lock is never held. |
| */ |
| static void mem_cgroup_lru_del_before_commit_swapcache(struct page *page) |
| { |
| unsigned long flags; |
| struct zone *zone = page_zone(page); |
| struct page_cgroup *pc = lookup_page_cgroup(page); |
| |
| spin_lock_irqsave(&zone->lru_lock, flags); |
| /* |
| * Forget old LRU when this page_cgroup is *not* used. This Used bit |
| * is guarded by lock_page() because the page is SwapCache. |
| */ |
| if (!PageCgroupUsed(pc)) |
| mem_cgroup_del_lru_list(page, page_lru(page)); |
| spin_unlock_irqrestore(&zone->lru_lock, flags); |
| } |
| |
| static void mem_cgroup_lru_add_after_commit_swapcache(struct page *page) |
| { |
| unsigned long flags; |
| struct zone *zone = page_zone(page); |
| struct page_cgroup *pc = lookup_page_cgroup(page); |
| |
| spin_lock_irqsave(&zone->lru_lock, flags); |
| /* link when the page is linked to LRU but page_cgroup isn't */ |
| if (PageLRU(page) && list_empty(&pc->lru)) |
| mem_cgroup_add_lru_list(page, page_lru(page)); |
| spin_unlock_irqrestore(&zone->lru_lock, flags); |
| } |
| |
| |
| void mem_cgroup_move_lists(struct page *page, |
| enum lru_list from, enum lru_list to) |
| { |
| if (mem_cgroup_disabled()) |
| return; |
| mem_cgroup_del_lru_list(page, from); |
| mem_cgroup_add_lru_list(page, to); |
| } |
| |
| int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem) |
| { |
| int ret; |
| |
| task_lock(task); |
| ret = task->mm && mm_match_cgroup(task->mm, mem); |
| task_unlock(task); |
| return ret; |
| } |
| |
| /* |
| * Calculate mapped_ratio under memory controller. This will be used in |
| * vmscan.c for deteremining we have to reclaim mapped pages. |
| */ |
| int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem) |
| { |
| long total, rss; |
| |
| /* |
| * usage is recorded in bytes. But, here, we assume the number of |
| * physical pages can be represented by "long" on any arch. |
| */ |
| total = (long) (mem->res.usage >> PAGE_SHIFT) + 1L; |
| rss = (long)mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS); |
| return (int)((rss * 100L) / total); |
| } |
| |
| /* |
| * prev_priority control...this will be used in memory reclaim path. |
| */ |
| int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem) |
| { |
| int prev_priority; |
| |
| spin_lock(&mem->reclaim_param_lock); |
| prev_priority = mem->prev_priority; |
| spin_unlock(&mem->reclaim_param_lock); |
| |
| return prev_priority; |
| } |
| |
| void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem, int priority) |
| { |
| spin_lock(&mem->reclaim_param_lock); |
| if (priority < mem->prev_priority) |
| mem->prev_priority = priority; |
| spin_unlock(&mem->reclaim_param_lock); |
| } |
| |
| void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem, int priority) |
| { |
| spin_lock(&mem->reclaim_param_lock); |
| mem->prev_priority = priority; |
| spin_unlock(&mem->reclaim_param_lock); |
| } |
| |
| static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_pages) |
| { |
| unsigned long active; |
| unsigned long inactive; |
| unsigned long gb; |
| unsigned long inactive_ratio; |
| |
| inactive = mem_cgroup_get_all_zonestat(memcg, LRU_INACTIVE_ANON); |
| active = mem_cgroup_get_all_zonestat(memcg, LRU_ACTIVE_ANON); |
| |
| gb = (inactive + active) >> (30 - PAGE_SHIFT); |
| if (gb) |
| inactive_ratio = int_sqrt(10 * gb); |
| else |
| inactive_ratio = 1; |
| |
| if (present_pages) { |
| present_pages[0] = inactive; |
| present_pages[1] = active; |
| } |
| |
| return inactive_ratio; |
| } |
| |
| int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg) |
| { |
| unsigned long active; |
| unsigned long inactive; |
| unsigned long present_pages[2]; |
| unsigned long inactive_ratio; |
| |
| inactive_ratio = calc_inactive_ratio(memcg, present_pages); |
| |
| inactive = present_pages[0]; |
| active = present_pages[1]; |
| |
| if (inactive * inactive_ratio < active) |
| return 1; |
| |
| return 0; |
| } |
| |
| unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg, |
| struct zone *zone, |
| enum lru_list lru) |
| { |
| int nid = zone->zone_pgdat->node_id; |
| int zid = zone_idx(zone); |
| struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid); |
| |
| return MEM_CGROUP_ZSTAT(mz, lru); |
| } |
| |
| struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg, |
| struct zone *zone) |
| { |
| int nid = zone->zone_pgdat->node_id; |
| int zid = zone_idx(zone); |
| struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid); |
| |
| return &mz->reclaim_stat; |
| } |
| |
| struct zone_reclaim_stat * |
| mem_cgroup_get_reclaim_stat_from_page(struct page *page) |
| { |
| struct page_cgroup *pc; |
| struct mem_cgroup_per_zone *mz; |
| |
| if (mem_cgroup_disabled()) |
| return NULL; |
| |
| pc = lookup_page_cgroup(page); |
| /* |
| * Used bit is set without atomic ops but after smp_wmb(). |
| * For making pc->mem_cgroup visible, insert smp_rmb() here. |
| */ |
| smp_rmb(); |
| if (!PageCgroupUsed(pc)) |
| return NULL; |
| |
| mz = page_cgroup_zoneinfo(pc); |
| if (!mz) |
| return NULL; |
| |
| return &mz->reclaim_stat; |
| } |
| |
| unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, |
| struct list_head *dst, |
| unsigned long *scanned, int order, |
| int mode, struct zone *z, |
| struct mem_cgroup *mem_cont, |
| int active, int file) |
| { |
| unsigned long nr_taken = 0; |
| struct page *page; |
| unsigned long scan; |
| LIST_HEAD(pc_list); |
| struct list_head *src; |
| struct page_cgroup *pc, *tmp; |
| int nid = z->zone_pgdat->node_id; |
| int zid = zone_idx(z); |
| struct mem_cgroup_per_zone *mz; |
| int lru = LRU_FILE * !!file + !!active; |
| |
| BUG_ON(!mem_cont); |
| mz = mem_cgroup_zoneinfo(mem_cont, nid, zid); |
| src = &mz->lists[lru]; |
| |
| scan = 0; |
| list_for_each_entry_safe_reverse(pc, tmp, src, lru) { |
| if (scan >= nr_to_scan) |
| break; |
| |
| page = pc->page; |
| if (unlikely(!PageCgroupUsed(pc))) |
| continue; |
| if (unlikely(!PageLRU(page))) |
| continue; |
| |
| scan++; |
| if (__isolate_lru_page(page, mode, file) == 0) { |
| list_move(&page->lru, dst); |
| nr_taken++; |
| } |
| } |
| |
| *scanned = scan; |
| return nr_taken; |
| } |
| |
| #define mem_cgroup_from_res_counter(counter, member) \ |
| container_of(counter, struct mem_cgroup, member) |
| |
| /* |
| * This routine finds the DFS walk successor. This routine should be |
| * called with hierarchy_mutex held |
| */ |
| static struct mem_cgroup * |
| mem_cgroup_get_next_node(struct mem_cgroup *curr, struct mem_cgroup *root_mem) |
| { |
| struct cgroup *cgroup, *curr_cgroup, *root_cgroup; |
| |
| curr_cgroup = curr->css.cgroup; |
| root_cgroup = root_mem->css.cgroup; |
| |
| if (!list_empty(&curr_cgroup->children)) { |
| /* |
| * Walk down to children |
| */ |
| mem_cgroup_put(curr); |
| cgroup = list_entry(curr_cgroup->children.next, |
| struct cgroup, sibling); |
| curr = mem_cgroup_from_cont(cgroup); |
| mem_cgroup_get(curr); |
| goto done; |
| } |
| |
| visit_parent: |
| if (curr_cgroup == root_cgroup) { |
| mem_cgroup_put(curr); |
| curr = root_mem; |
| mem_cgroup_get(curr); |
| goto done; |
| } |
| |
| /* |
| * Goto next sibling |
| */ |
| if (curr_cgroup->sibling.next != &curr_cgroup->parent->children) { |
| mem_cgroup_put(curr); |
| cgroup = list_entry(curr_cgroup->sibling.next, struct cgroup, |
| sibling); |
| curr = mem_cgroup_from_cont(cgroup); |
| mem_cgroup_get(curr); |
| goto done; |
| } |
| |
| /* |
| * Go up to next parent and next parent's sibling if need be |
| */ |
| curr_cgroup = curr_cgroup->parent; |
| goto visit_parent; |
| |
| done: |
| root_mem->last_scanned_child = curr; |
| return curr; |
| } |
| |
| /* |
| * Visit the first child (need not be the first child as per the ordering |
| * of the cgroup list, since we track last_scanned_child) of @mem and use |
| * that to reclaim free pages from. |
| */ |
| static struct mem_cgroup * |
| mem_cgroup_get_first_node(struct mem_cgroup *root_mem) |
| { |
| struct cgroup *cgroup; |
| struct mem_cgroup *ret; |
| bool obsolete; |
| |
| obsolete = mem_cgroup_is_obsolete(root_mem->last_scanned_child); |
| |
| /* |
| * Scan all children under the mem_cgroup mem |
| */ |
| mutex_lock(&mem_cgroup_subsys.hierarchy_mutex); |
| if (list_empty(&root_mem->css.cgroup->children)) { |
| ret = root_mem; |
| goto done; |
| } |
| |
| if (!root_mem->last_scanned_child || obsolete) { |
| |
| if (obsolete && root_mem->last_scanned_child) |
| mem_cgroup_put(root_mem->last_scanned_child); |
| |
| cgroup = list_first_entry(&root_mem->css.cgroup->children, |
| struct cgroup, sibling); |
| ret = mem_cgroup_from_cont(cgroup); |
| mem_cgroup_get(ret); |
| } else |
| ret = mem_cgroup_get_next_node(root_mem->last_scanned_child, |
| root_mem); |
| |
| done: |
| root_mem->last_scanned_child = ret; |
| mutex_unlock(&mem_cgroup_subsys.hierarchy_mutex); |
| return ret; |
| } |
| |
| static bool mem_cgroup_check_under_limit(struct mem_cgroup *mem) |
| { |
| if (do_swap_account) { |
| if (res_counter_check_under_limit(&mem->res) && |
| res_counter_check_under_limit(&mem->memsw)) |
| return true; |
| } else |
| if (res_counter_check_under_limit(&mem->res)) |
| return true; |
| return false; |
| } |
| |
| static unsigned int get_swappiness(struct mem_cgroup *memcg) |
| { |
| struct cgroup *cgrp = memcg->css.cgroup; |
| unsigned int swappiness; |
| |
| /* root ? */ |
| if (cgrp->parent == NULL) |
| return vm_swappiness; |
| |
| spin_lock(&memcg->reclaim_param_lock); |
| swappiness = memcg->swappiness; |
| spin_unlock(&memcg->reclaim_param_lock); |
| |
| return swappiness; |
| } |
| |
| /* |
| * Dance down the hierarchy if needed to reclaim memory. We remember the |
| * last child we reclaimed from, so that we don't end up penalizing |
| * one child extensively based on its position in the children list. |
| * |
| * root_mem is the original ancestor that we've been reclaim from. |
| */ |
| static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem, |
| gfp_t gfp_mask, bool noswap) |
| { |
| struct mem_cgroup *next_mem; |
| int ret = 0; |
| |
| /* |
| * Reclaim unconditionally and don't check for return value. |
| * We need to reclaim in the current group and down the tree. |
| * One might think about checking for children before reclaiming, |
| * but there might be left over accounting, even after children |
| * have left. |
| */ |
| ret = try_to_free_mem_cgroup_pages(root_mem, gfp_mask, noswap, |
| get_swappiness(root_mem)); |
| if (mem_cgroup_check_under_limit(root_mem)) |
| return 0; |
| if (!root_mem->use_hierarchy) |
| return ret; |
| |
| next_mem = mem_cgroup_get_first_node(root_mem); |
| |
| while (next_mem != root_mem) { |
| if (mem_cgroup_is_obsolete(next_mem)) { |
| mem_cgroup_put(next_mem); |
| next_mem = mem_cgroup_get_first_node(root_mem); |
| continue; |
| } |
| ret = try_to_free_mem_cgroup_pages(next_mem, gfp_mask, noswap, |
| get_swappiness(next_mem)); |
| if (mem_cgroup_check_under_limit(root_mem)) |
| return 0; |
| mutex_lock(&mem_cgroup_subsys.hierarchy_mutex); |
| next_mem = mem_cgroup_get_next_node(next_mem, root_mem); |
| mutex_unlock(&mem_cgroup_subsys.hierarchy_mutex); |
| } |
| return ret; |
| } |
| |
| bool mem_cgroup_oom_called(struct task_struct *task) |
| { |
| bool ret = false; |
| struct mem_cgroup *mem; |
| struct mm_struct *mm; |
| |
| rcu_read_lock(); |
| mm = task->mm; |
| if (!mm) |
| mm = &init_mm; |
| mem = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
| if (mem && time_before(jiffies, mem->last_oom_jiffies + HZ/10)) |
| ret = true; |
| rcu_read_unlock(); |
| return ret; |
| } |
| /* |
| * Unlike exported interface, "oom" parameter is added. if oom==true, |
| * oom-killer can be invoked. |
| */ |
| static int __mem_cgroup_try_charge(struct mm_struct *mm, |
| gfp_t gfp_mask, struct mem_cgroup **memcg, |
| bool oom) |
| { |
| struct mem_cgroup *mem, *mem_over_limit; |
| int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; |
| struct res_counter *fail_res; |
| |
| if (unlikely(test_thread_flag(TIF_MEMDIE))) { |
| /* Don't account this! */ |
| *memcg = NULL; |
| return 0; |
| } |
| |
| /* |
| * We always charge the cgroup the mm_struct belongs to. |
| * The mm_struct's mem_cgroup changes on task migration if the |
| * thread group leader migrates. It's possible that mm is not |
| * set, if so charge the init_mm (happens for pagecache usage). |
| */ |
| mem = *memcg; |
| if (likely(!mem)) { |
| mem = try_get_mem_cgroup_from_mm(mm); |
| *memcg = mem; |
| } else { |
| css_get(&mem->css); |
| } |
| if (unlikely(!mem)) |
| return 0; |
| |
| VM_BUG_ON(mem_cgroup_is_obsolete(mem)); |
| |
| while (1) { |
| int ret; |
| bool noswap = false; |
| |
| ret = res_counter_charge(&mem->res, PAGE_SIZE, &fail_res); |
| if (likely(!ret)) { |
| if (!do_swap_account) |
| break; |
| ret = res_counter_charge(&mem->memsw, PAGE_SIZE, |
| &fail_res); |
| if (likely(!ret)) |
| break; |
| /* mem+swap counter fails */ |
| res_counter_uncharge(&mem->res, PAGE_SIZE); |
| noswap = true; |
| mem_over_limit = mem_cgroup_from_res_counter(fail_res, |
| memsw); |
| } else |
| /* mem counter fails */ |
| mem_over_limit = mem_cgroup_from_res_counter(fail_res, |
| res); |
| |
| if (!(gfp_mask & __GFP_WAIT)) |
| goto nomem; |
| |
| ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, gfp_mask, |
| noswap); |
| |
| /* |
| * try_to_free_mem_cgroup_pages() might not give us a full |
| * picture of reclaim. Some pages are reclaimed and might be |
| * moved to swap cache or just unmapped from the cgroup. |
| * Check the limit again to see if the reclaim reduced the |
| * current usage of the cgroup before giving up |
| * |
| */ |
| if (mem_cgroup_check_under_limit(mem_over_limit)) |
| continue; |
| |
| if (!nr_retries--) { |
| if (oom) { |
| mutex_lock(&memcg_tasklist); |
| mem_cgroup_out_of_memory(mem_over_limit, gfp_mask); |
| mutex_unlock(&memcg_tasklist); |
| mem_over_limit->last_oom_jiffies = jiffies; |
| } |
| goto nomem; |
| } |
| } |
| return 0; |
| nomem: |
| css_put(&mem->css); |
| return -ENOMEM; |
| } |
| |
| static struct mem_cgroup *try_get_mem_cgroup_from_swapcache(struct page *page) |
| { |
| struct mem_cgroup *mem; |
| swp_entry_t ent; |
| |
| if (!PageSwapCache(page)) |
| return NULL; |
| |
| ent.val = page_private(page); |
| mem = lookup_swap_cgroup(ent); |
| if (!mem) |
| return NULL; |
| if (!css_tryget(&mem->css)) |
| return NULL; |
| return mem; |
| } |
| |
| /* |
| * commit a charge got by __mem_cgroup_try_charge() and makes page_cgroup to be |
| * USED state. If already USED, uncharge and return. |
| */ |
| |
| static void __mem_cgroup_commit_charge(struct mem_cgroup *mem, |
| struct page_cgroup *pc, |
| enum charge_type ctype) |
| { |
| /* try_charge() can return NULL to *memcg, taking care of it. */ |
| if (!mem) |
| return; |
| |
| lock_page_cgroup(pc); |
| if (unlikely(PageCgroupUsed(pc))) { |
| unlock_page_cgroup(pc); |
| res_counter_uncharge(&mem->res, PAGE_SIZE); |
| if (do_swap_account) |
| res_counter_uncharge(&mem->memsw, PAGE_SIZE); |
| css_put(&mem->css); |
| return; |
| } |
| pc->mem_cgroup = mem; |
| smp_wmb(); |
| pc->flags = pcg_default_flags[ctype]; |
| |
| mem_cgroup_charge_statistics(mem, pc, true); |
| |
| unlock_page_cgroup(pc); |
| } |
| |
| /** |
| * mem_cgroup_move_account - move account of the page |
| * @pc: page_cgroup of the page. |
| * @from: mem_cgroup which the page is moved from. |
| * @to: mem_cgroup which the page is moved to. @from != @to. |
| * |
| * The caller must confirm following. |
| * - page is not on LRU (isolate_page() is useful.) |
| * |
| * returns 0 at success, |
| * returns -EBUSY when lock is busy or "pc" is unstable. |
| * |
| * This function does "uncharge" from old cgroup but doesn't do "charge" to |
| * new cgroup. It should be done by a caller. |
| */ |
| |
| static int mem_cgroup_move_account(struct page_cgroup *pc, |
| struct mem_cgroup *from, struct mem_cgroup *to) |
| { |
| struct mem_cgroup_per_zone *from_mz, *to_mz; |
| int nid, zid; |
| int ret = -EBUSY; |
| |
| VM_BUG_ON(from == to); |
| VM_BUG_ON(PageLRU(pc->page)); |
| |
| nid = page_cgroup_nid(pc); |
| zid = page_cgroup_zid(pc); |
| from_mz = mem_cgroup_zoneinfo(from, nid, zid); |
| to_mz = mem_cgroup_zoneinfo(to, nid, zid); |
| |
| if (!trylock_page_cgroup(pc)) |
| return ret; |
| |
| if (!PageCgroupUsed(pc)) |
| goto out; |
| |
| if (pc->mem_cgroup != from) |
| goto out; |
| |
| css_put(&from->css); |
| res_counter_uncharge(&from->res, PAGE_SIZE); |
| mem_cgroup_charge_statistics(from, pc, false); |
| if (do_swap_account) |
| res_counter_uncharge(&from->memsw, PAGE_SIZE); |
| pc->mem_cgroup = to; |
| mem_cgroup_charge_statistics(to, pc, true); |
| css_get(&to->css); |
| ret = 0; |
| out: |
| unlock_page_cgroup(pc); |
| return ret; |
| } |
| |
| /* |
| * move charges to its parent. |
| */ |
| |
| static int mem_cgroup_move_parent(struct page_cgroup *pc, |
| struct mem_cgroup *child, |
| gfp_t gfp_mask) |
| { |
| struct page *page = pc->page; |
| struct cgroup *cg = child->css.cgroup; |
| struct cgroup *pcg = cg->parent; |
| struct mem_cgroup *parent; |
| int ret; |
| |
| /* Is ROOT ? */ |
| if (!pcg) |
| return -EINVAL; |
| |
| |
| parent = mem_cgroup_from_cont(pcg); |
| |
| |
| ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false); |
| if (ret || !parent) |
| return ret; |
| |
| if (!get_page_unless_zero(page)) |
| return -EBUSY; |
| |
| ret = isolate_lru_page(page); |
| |
| if (ret) |
| goto cancel; |
| |
| ret = mem_cgroup_move_account(pc, child, parent); |
| |
| /* drop extra refcnt by try_charge() (move_account increment one) */ |
| css_put(&parent->css); |
| putback_lru_page(page); |
| if (!ret) { |
| put_page(page); |
| return 0; |
| } |
| /* uncharge if move fails */ |
| cancel: |
| res_counter_uncharge(&parent->res, PAGE_SIZE); |
| if (do_swap_account) |
| res_counter_uncharge(&parent->memsw, PAGE_SIZE); |
| put_page(page); |
| return ret; |
| } |
| |
| /* |
| * Charge the memory controller for page usage. |
| * Return |
| * 0 if the charge was successful |
| * < 0 if the cgroup is over its limit |
| */ |
| static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, |
| gfp_t gfp_mask, enum charge_type ctype, |
| struct mem_cgroup *memcg) |
| { |
| struct mem_cgroup *mem; |
| struct page_cgroup *pc; |
| int ret; |
| |
| pc = lookup_page_cgroup(page); |
| /* can happen at boot */ |
| if (unlikely(!pc)) |
| return 0; |
| prefetchw(pc); |
| |
| mem = memcg; |
| ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true); |
| if (ret || !mem) |
| return ret; |
| |
| __mem_cgroup_commit_charge(mem, pc, ctype); |
| return 0; |
| } |
| |
| int mem_cgroup_newpage_charge(struct page *page, |
| struct mm_struct *mm, gfp_t gfp_mask) |
| { |
| if (mem_cgroup_disabled()) |
| return 0; |
| if (PageCompound(page)) |
| return 0; |
| /* |
| * If already mapped, we don't have to account. |
| * If page cache, page->mapping has address_space. |
| * But page->mapping may have out-of-use anon_vma pointer, |
| * detecit it by PageAnon() check. newly-mapped-anon's page->mapping |
| * is NULL. |
| */ |
| if (page_mapped(page) || (page->mapping && !PageAnon(page))) |
| return 0; |
| if (unlikely(!mm)) |
| mm = &init_mm; |
| return mem_cgroup_charge_common(page, mm, gfp_mask, |
| MEM_CGROUP_CHARGE_TYPE_MAPPED, NULL); |
| } |
| |
| int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, |
| gfp_t gfp_mask) |
| { |
| struct mem_cgroup *mem = NULL; |
| int ret; |
| |
| if (mem_cgroup_disabled()) |
| return 0; |
| if (PageCompound(page)) |
| return 0; |
| /* |
| * Corner case handling. This is called from add_to_page_cache() |
| * in usual. But some FS (shmem) precharges this page before calling it |
| * and call add_to_page_cache() with GFP_NOWAIT. |
| * |
| * For GFP_NOWAIT case, the page may be pre-charged before calling |
| * add_to_page_cache(). (See shmem.c) check it here and avoid to call |
| * charge twice. (It works but has to pay a bit larger cost.) |
| * And when the page is SwapCache, it should take swap information |
| * into account. This is under lock_page() now. |
| */ |
| if (!(gfp_mask & __GFP_WAIT)) { |
| struct page_cgroup *pc; |
| |
| |
| pc = lookup_page_cgroup(page); |
| if (!pc) |
| return 0; |
| lock_page_cgroup(pc); |
| if (PageCgroupUsed(pc)) { |
| unlock_page_cgroup(pc); |
| return 0; |
| } |
| unlock_page_cgroup(pc); |
| } |
| |
| if (do_swap_account && PageSwapCache(page)) { |
| mem = try_get_mem_cgroup_from_swapcache(page); |
| if (mem) |
| mm = NULL; |
| else |
| mem = NULL; |
| /* SwapCache may be still linked to LRU now. */ |
| mem_cgroup_lru_del_before_commit_swapcache(page); |
| } |
| |
| if (unlikely(!mm && !mem)) |
| mm = &init_mm; |
| |
| if (page_is_file_cache(page)) |
| return mem_cgroup_charge_common(page, mm, gfp_mask, |
| MEM_CGROUP_CHARGE_TYPE_CACHE, NULL); |
| |
| ret = mem_cgroup_charge_common(page, mm, gfp_mask, |
| MEM_CGROUP_CHARGE_TYPE_SHMEM, mem); |
| if (mem) |
| css_put(&mem->css); |
| if (PageSwapCache(page)) |
| mem_cgroup_lru_add_after_commit_swapcache(page); |
| |
| if (do_swap_account && !ret && PageSwapCache(page)) { |
| swp_entry_t ent = {.val = page_private(page)}; |
| /* avoid double counting */ |
| mem = swap_cgroup_record(ent, NULL); |
| if (mem) { |
| res_counter_uncharge(&mem->memsw, PAGE_SIZE); |
| mem_cgroup_put(mem); |
| } |
| } |
| return ret; |
| } |
| |
| /* |
| * While swap-in, try_charge -> commit or cancel, the page is locked. |
| * And when try_charge() successfully returns, one refcnt to memcg without |
| * struct page_cgroup is aquired. This refcnt will be cumsumed by |
| * "commit()" or removed by "cancel()" |
| */ |
| int mem_cgroup_try_charge_swapin(struct mm_struct *mm, |
| struct page *page, |
| gfp_t mask, struct mem_cgroup **ptr) |
| { |
| struct mem_cgroup *mem; |
| int ret; |
| |
| if (mem_cgroup_disabled()) |
| return 0; |
| |
| if (!do_swap_account) |
| goto charge_cur_mm; |
| /* |
| * A racing thread's fault, or swapoff, may have already updated |
| * the pte, and even removed page from swap cache: return success |
| * to go on to do_swap_page()'s pte_same() test, which should fail. |
| */ |
| if (!PageSwapCache(page)) |
| return 0; |
| mem = try_get_mem_cgroup_from_swapcache(page); |
| if (!mem) |
| goto charge_cur_mm; |
| *ptr = mem; |
| ret = __mem_cgroup_try_charge(NULL, mask, ptr, true); |
| /* drop extra refcnt from tryget */ |
| css_put(&mem->css); |
| return ret; |
| charge_cur_mm: |
| if (unlikely(!mm)) |
| mm = &init_mm; |
| return __mem_cgroup_try_charge(mm, mask, ptr, true); |
| } |
| |
| void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr) |
| { |
| struct page_cgroup *pc; |
| |
| if (mem_cgroup_disabled()) |
| return; |
| if (!ptr) |
| return; |
| pc = lookup_page_cgroup(page); |
| mem_cgroup_lru_del_before_commit_swapcache(page); |
| __mem_cgroup_commit_charge(ptr, pc, MEM_CGROUP_CHARGE_TYPE_MAPPED); |
| mem_cgroup_lru_add_after_commit_swapcache(page); |
| /* |
| * Now swap is on-memory. This means this page may be |
| * counted both as mem and swap....double count. |
| * Fix it by uncharging from memsw. Basically, this SwapCache is stable |
| * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page() |
| * may call delete_from_swap_cache() before reach here. |
| */ |
| if (do_swap_account && PageSwapCache(page)) { |
| swp_entry_t ent = {.val = page_private(page)}; |
| struct mem_cgroup *memcg; |
| memcg = swap_cgroup_record(ent, NULL); |
| if (memcg) { |
| res_counter_uncharge(&memcg->memsw, PAGE_SIZE); |
| mem_cgroup_put(memcg); |
| } |
| |
| } |
| /* add this page(page_cgroup) to the LRU we want. */ |
| |
| } |
| |
| void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem) |
| { |
| if (mem_cgroup_disabled()) |
| return; |
| if (!mem) |
| return; |
| res_counter_uncharge(&mem->res, PAGE_SIZE); |
| if (do_swap_account) |
| res_counter_uncharge(&mem->memsw, PAGE_SIZE); |
| css_put(&mem->css); |
| } |
| |
| |
| /* |
| * uncharge if !page_mapped(page) |
| */ |
| static struct mem_cgroup * |
| __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype) |
| { |
| struct page_cgroup *pc; |
| struct mem_cgroup *mem = NULL; |
| struct mem_cgroup_per_zone *mz; |
| |
| if (mem_cgroup_disabled()) |
| return NULL; |
| |
| if (PageSwapCache(page)) |
| return NULL; |
| |
| /* |
| * Check if our page_cgroup is valid |
| */ |
| pc = lookup_page_cgroup(page); |
| if (unlikely(!pc || !PageCgroupUsed(pc))) |
| return NULL; |
| |
| lock_page_cgroup(pc); |
| |
| mem = pc->mem_cgroup; |
| |
| if (!PageCgroupUsed(pc)) |
| goto unlock_out; |
| |
| switch (ctype) { |
| case MEM_CGROUP_CHARGE_TYPE_MAPPED: |
| if (page_mapped(page)) |
| goto unlock_out; |
| break; |
| case MEM_CGROUP_CHARGE_TYPE_SWAPOUT: |
| if (!PageAnon(page)) { /* Shared memory */ |
| if (page->mapping && !page_is_file_cache(page)) |
| goto unlock_out; |
| } else if (page_mapped(page)) /* Anon */ |
| goto unlock_out; |
| break; |
| default: |
| break; |
| } |
| |
| res_counter_uncharge(&mem->res, PAGE_SIZE); |
| if (do_swap_account && (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT)) |
| res_counter_uncharge(&mem->memsw, PAGE_SIZE); |
| |
| mem_cgroup_charge_statistics(mem, pc, false); |
| ClearPageCgroupUsed(pc); |
| /* |
| * pc->mem_cgroup is not cleared here. It will be accessed when it's |
| * freed from LRU. This is safe because uncharged page is expected not |
| * to be reused (freed soon). Exception is SwapCache, it's handled by |
| * special functions. |
| */ |
| |
| mz = page_cgroup_zoneinfo(pc); |
| unlock_page_cgroup(pc); |
| |
| /* at swapout, this memcg will be accessed to record to swap */ |
| if (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT) |
| css_put(&mem->css); |
| |
| return mem; |
| |
| unlock_out: |
| unlock_page_cgroup(pc); |
| return NULL; |
| } |
| |
| void mem_cgroup_uncharge_page(struct page *page) |
| { |
| /* early check. */ |
| if (page_mapped(page)) |
| return; |
| if (page->mapping && !PageAnon(page)) |
| return; |
| __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED); |
| } |
| |
| void mem_cgroup_uncharge_cache_page(struct page *page) |
| { |
| VM_BUG_ON(page_mapped(page)); |
| VM_BUG_ON(page->mapping); |
| __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE); |
| } |
| |
| /* |
| * called from __delete_from_swap_cache() and drop "page" account. |
| * memcg information is recorded to swap_cgroup of "ent" |
| */ |
| void mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent) |
| { |
| struct mem_cgroup *memcg; |
| |
| memcg = __mem_cgroup_uncharge_common(page, |
| MEM_CGROUP_CHARGE_TYPE_SWAPOUT); |
| /* record memcg information */ |
| if (do_swap_account && memcg) { |
| swap_cgroup_record(ent, memcg); |
| mem_cgroup_get(memcg); |
| } |
| if (memcg) |
| css_put(&memcg->css); |
| } |
| |
| #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
| /* |
| * called from swap_entry_free(). remove record in swap_cgroup and |
| * uncharge "memsw" account. |
| */ |
| void mem_cgroup_uncharge_swap(swp_entry_t ent) |
| { |
| struct mem_cgroup *memcg; |
| |
| if (!do_swap_account) |
| return; |
| |
| memcg = swap_cgroup_record(ent, NULL); |
| if (memcg) { |
| res_counter_uncharge(&memcg->memsw, PAGE_SIZE); |
| mem_cgroup_put(memcg); |
| } |
| } |
| #endif |
| |
| /* |
| * Before starting migration, account PAGE_SIZE to mem_cgroup that the old |
| * page belongs to. |
| */ |
| int mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr) |
| { |
| struct page_cgroup *pc; |
| struct mem_cgroup *mem = NULL; |
| int ret = 0; |
| |
| if (mem_cgroup_disabled()) |
| return 0; |
| |
| pc = lookup_page_cgroup(page); |
| lock_page_cgroup(pc); |
| if (PageCgroupUsed(pc)) { |
| mem = pc->mem_cgroup; |
| css_get(&mem->css); |
| } |
| unlock_page_cgroup(pc); |
| |
| if (mem) { |
| ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false); |
| css_put(&mem->css); |
| } |
| *ptr = mem; |
| return ret; |
| } |
| |
| /* remove redundant charge if migration failed*/ |
| void mem_cgroup_end_migration(struct mem_cgroup *mem, |
| struct page *oldpage, struct page *newpage) |
| { |
| struct page *target, *unused; |
| struct page_cgroup *pc; |
| enum charge_type ctype; |
| |
| if (!mem) |
| return; |
| |
| /* at migration success, oldpage->mapping is NULL. */ |
| if (oldpage->mapping) { |
| target = oldpage; |
| unused = NULL; |
| } else { |
| target = newpage; |
| unused = oldpage; |
| } |
| |
| if (PageAnon(target)) |
| ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED; |
| else if (page_is_file_cache(target)) |
| ctype = MEM_CGROUP_CHARGE_TYPE_CACHE; |
| else |
| ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM; |
| |
| /* unused page is not on radix-tree now. */ |
| if (unused) |
| __mem_cgroup_uncharge_common(unused, ctype); |
| |
| pc = lookup_page_cgroup(target); |
| /* |
| * __mem_cgroup_commit_charge() check PCG_USED bit of page_cgroup. |
| * So, double-counting is effectively avoided. |
| */ |
| __mem_cgroup_commit_charge(mem, pc, ctype); |
| |
| /* |
| * Both of oldpage and newpage are still under lock_page(). |
| * Then, we don't have to care about race in radix-tree. |
| * But we have to be careful that this page is unmapped or not. |
| * |
| * There is a case for !page_mapped(). At the start of |
| * migration, oldpage was mapped. But now, it's zapped. |
| * But we know *target* page is not freed/reused under us. |
| * mem_cgroup_uncharge_page() does all necessary checks. |
| */ |
| if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED) |
| mem_cgroup_uncharge_page(target); |
| } |
| |
| /* |
| * A call to try to shrink memory usage under specified resource controller. |
| * This is typically used for page reclaiming for shmem for reducing side |
| * effect of page allocation from shmem, which is used by some mem_cgroup. |
| */ |
| int mem_cgroup_shrink_usage(struct page *page, |
| struct mm_struct *mm, |
| gfp_t gfp_mask) |
| { |
| struct mem_cgroup *mem = NULL; |
| int progress = 0; |
| int retry = MEM_CGROUP_RECLAIM_RETRIES; |
| |
| if (mem_cgroup_disabled()) |
| return 0; |
| if (page) |
| mem = try_get_mem_cgroup_from_swapcache(page); |
| if (!mem && mm) |
| mem = try_get_mem_cgroup_from_mm(mm); |
| if (unlikely(!mem)) |
| return 0; |
| |
| do { |
| progress = mem_cgroup_hierarchical_reclaim(mem, gfp_mask, true); |
| progress += mem_cgroup_check_under_limit(mem); |
| } while (!progress && --retry); |
| |
| css_put(&mem->css); |
| if (!retry) |
| return -ENOMEM; |
| return 0; |
| } |
| |
| static DEFINE_MUTEX(set_limit_mutex); |
| |
| static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, |
| unsigned long long val) |
| { |
| |
| int retry_count = MEM_CGROUP_RECLAIM_RETRIES; |
| int progress; |
| u64 memswlimit; |
| int ret = 0; |
| |
| while (retry_count) { |
| if (signal_pending(current)) { |
| ret = -EINTR; |
| break; |
| } |
| /* |
| * Rather than hide all in some function, I do this in |
| * open coded manner. You see what this really does. |
| * We have to guarantee mem->res.limit < mem->memsw.limit. |
| */ |
| mutex_lock(&set_limit_mutex); |
| memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
| if (memswlimit < val) { |
| ret = -EINVAL; |
| mutex_unlock(&set_limit_mutex); |
| break; |
| } |
| ret = res_counter_set_limit(&memcg->res, val); |
| mutex_unlock(&set_limit_mutex); |
| |
| if (!ret) |
| break; |
| |
| progress = mem_cgroup_hierarchical_reclaim(memcg, GFP_KERNEL, |
| false); |
| if (!progress) retry_count--; |
| } |
| |
| return ret; |
| } |
| |
| int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, |
| unsigned long long val) |
| { |
| int retry_count = MEM_CGROUP_RECLAIM_RETRIES; |
| u64 memlimit, oldusage, curusage; |
| int ret; |
| |
| if (!do_swap_account) |
| return -EINVAL; |
| |
| while (retry_count) { |
| if (signal_pending(current)) { |
| ret = -EINTR; |
| break; |
| } |
| /* |
| * Rather than hide all in some function, I do this in |
| * open coded manner. You see what this really does. |
| * We have to guarantee mem->res.limit < mem->memsw.limit. |
| */ |
| mutex_lock(&set_limit_mutex); |
| memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); |
| if (memlimit > val) { |
| ret = -EINVAL; |
| mutex_unlock(&set_limit_mutex); |
| break; |
| } |
| ret = res_counter_set_limit(&memcg->memsw, val); |
| mutex_unlock(&set_limit_mutex); |
| |
| if (!ret) |
| break; |
| |
| oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); |
| mem_cgroup_hierarchical_reclaim(memcg, GFP_KERNEL, true); |
| curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); |
| if (curusage >= oldusage) |
| retry_count--; |
| } |
| return ret; |
| } |
| |
| /* |
| * This routine traverse page_cgroup in given list and drop them all. |
| * *And* this routine doesn't reclaim page itself, just removes page_cgroup. |
| */ |
| static int mem_cgroup_force_empty_list(struct mem_cgroup *mem, |
| int node, int zid, enum lru_list lru) |
| { |
| struct zone *zone; |
| struct mem_cgroup_per_zone *mz; |
| struct page_cgroup *pc, *busy; |
| unsigned long flags, loop; |
| struct list_head *list; |
| int ret = 0; |
| |
| zone = &NODE_DATA(node)->node_zones[zid]; |
| mz = mem_cgroup_zoneinfo(mem, node, zid); |
| list = &mz->lists[lru]; |
| |
| loop = MEM_CGROUP_ZSTAT(mz, lru); |
| /* give some margin against EBUSY etc...*/ |
| loop += 256; |
| busy = NULL; |
| while (loop--) { |
| ret = 0; |
| spin_lock_irqsave(&zone->lru_lock, flags); |
| if (list_empty(list)) { |
| spin_unlock_irqrestore(&zone->lru_lock, flags); |
| break; |
| } |
| pc = list_entry(list->prev, struct page_cgroup, lru); |
| if (busy == pc) { |
| list_move(&pc->lru, list); |
| busy = 0; |
| spin_unlock_irqrestore(&zone->lru_lock, flags); |
| continue; |
| } |
| spin_unlock_irqrestore(&zone->lru_lock, flags); |
| |
| ret = mem_cgroup_move_parent(pc, mem, GFP_KERNEL); |
| if (ret == -ENOMEM) |
| break; |
| |
| if (ret == -EBUSY || ret == -EINVAL) { |
| /* found lock contention or "pc" is obsolete. */ |
| busy = pc; |
| cond_resched(); |
| } else |
| busy = NULL; |
| } |
| |
| if (!ret && !list_empty(list)) |
| return -EBUSY; |
| return ret; |
| } |
| |
| /* |
| * make mem_cgroup's charge to be 0 if there is no task. |
| * This enables deleting this mem_cgroup. |
| */ |
| static int mem_cgroup_force_empty(struct mem_cgroup *mem, bool free_all) |
| { |
| int ret; |
| int node, zid, shrink; |
| int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; |
| struct cgroup *cgrp = mem->css.cgroup; |
| |
| css_get(&mem->css); |
| |
| shrink = 0; |
| /* should free all ? */ |
| if (free_all) |
| goto try_to_free; |
| move_account: |
| while (mem->res.usage > 0) { |
| ret = -EBUSY; |
| if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children)) |
| goto out; |
| ret = -EINTR; |
| if (signal_pending(current)) |
| goto out; |
| /* This is for making all *used* pages to be on LRU. */ |
| lru_add_drain_all(); |
| ret = 0; |
| for_each_node_state(node, N_POSSIBLE) { |
| for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) { |
| enum lru_list l; |
| for_each_lru(l) { |
| ret = mem_cgroup_force_empty_list(mem, |
| node, zid, l); |
| if (ret) |
| break; |
| } |
| } |
| if (ret) |
| break; |
| } |
| /* it seems parent cgroup doesn't have enough mem */ |
| if (ret == -ENOMEM) |
| goto try_to_free; |
| cond_resched(); |
| } |
| ret = 0; |
| out: |
| css_put(&mem->css); |
| return ret; |
| |
| try_to_free: |
| /* returns EBUSY if there is a task or if we come here twice. */ |
| if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) { |
| ret = -EBUSY; |
| goto out; |
| } |
| /* we call try-to-free pages for make this cgroup empty */ |
| lru_add_drain_all(); |
| /* try to free all pages in this cgroup */ |
| shrink = 1; |
| while (nr_retries && mem->res.usage > 0) { |
| int progress; |
| |
| if (signal_pending(current)) { |
| ret = -EINTR; |
| goto out; |
| } |
| progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL, |
| false, get_swappiness(mem)); |
| if (!progress) { |
| nr_retries--; |
| /* maybe some writeback is necessary */ |
| congestion_wait(WRITE, HZ/10); |
| } |
| |
| } |
| lru_add_drain(); |
| /* try move_account...there may be some *locked* pages. */ |
| if (mem->res.usage) |
| goto move_account; |
| ret = 0; |
| goto out; |
| } |
| |
| int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event) |
| { |
| return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true); |
| } |
| |
| |
| static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft) |
| { |
| return mem_cgroup_from_cont(cont)->use_hierarchy; |
| } |
| |
| static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft, |
| u64 val) |
| { |
| int retval = 0; |
| struct mem_cgroup *mem = mem_cgroup_from_cont(cont); |
| struct cgroup *parent = cont->parent; |
| struct mem_cgroup *parent_mem = NULL; |
| |
| if (parent) |
| parent_mem = mem_cgroup_from_cont(parent); |
| |
| cgroup_lock(); |
| /* |
| * If parent's use_hiearchy is set, we can't make any modifications |
| * in the child subtrees. If it is unset, then the change can |
| * occur, provided the current cgroup has no children. |
| * |
| * For the root cgroup, parent_mem is NULL, we allow value to be |
| * set if there are no children. |
| */ |
| if ((!parent_mem || !parent_mem->use_hierarchy) && |
| (val == 1 || val == 0)) { |
| if (list_empty(&cont->children)) |
| mem->use_hierarchy = val; |
| else |
| retval = -EBUSY; |
| } else |
| retval = -EINVAL; |
| cgroup_unlock(); |
| |
| return retval; |
| } |
| |
| static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft) |
| { |
| struct mem_cgroup *mem = mem_cgroup_from_cont(cont); |
| u64 val = 0; |
| int type, name; |
| |
| type = MEMFILE_TYPE(cft->private); |
| name = MEMFILE_ATTR(cft->private); |
| switch (type) { |
| case _MEM: |
| val = res_counter_read_u64(&mem->res, name); |
| break; |
| case _MEMSWAP: |
| if (do_swap_account) |
| val = res_counter_read_u64(&mem->memsw, name); |
| break; |
| default: |
| BUG(); |
| break; |
| } |
| return val; |
| } |
| /* |
| * The user of this function is... |
| * RES_LIMIT. |
| */ |
| static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft, |
| const char *buffer) |
| { |
| struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
| int type, name; |
| unsigned long long val; |
| int ret; |
| |
| type = MEMFILE_TYPE(cft->private); |
| name = MEMFILE_ATTR(cft->private); |
| switch (name) { |
| case RES_LIMIT: |
| /* This function does all necessary parse...reuse it */ |
| ret = res_counter_memparse_write_strategy(buffer, &val); |
| if (ret) |
| break; |
| if (type == _MEM) |
| ret = mem_cgroup_resize_limit(memcg, val); |
| else |
| ret = mem_cgroup_resize_memsw_limit(memcg, val); |
| break; |
| default: |
| ret = -EINVAL; /* should be BUG() ? */ |
| break; |
| } |
| return ret; |
| } |
| |
| static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg, |
| unsigned long long *mem_limit, unsigned long long *memsw_limit) |
| { |
| struct cgroup *cgroup; |
| unsigned long long min_limit, min_memsw_limit, tmp; |
| |
| min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT); |
| min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
| cgroup = memcg->css.cgroup; |
| if (!memcg->use_hierarchy) |
| goto out; |
| |
| while (cgroup->parent) { |
| cgroup = cgroup->parent; |
| memcg = mem_cgroup_from_cont(cgroup); |
| if (!memcg->use_hierarchy) |
| break; |
| tmp = res_counter_read_u64(&memcg->res, RES_LIMIT); |
| min_limit = min(min_limit, tmp); |
| tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
| min_memsw_limit = min(min_memsw_limit, tmp); |
| } |
| out: |
| *mem_limit = min_limit; |
| *memsw_limit = min_memsw_limit; |
| return; |
| } |
| |
| static int mem_cgroup_reset(struct cgroup *cont, unsigned int event) |
| { |
| struct mem_cgroup *mem; |
| int type, name; |
| |
| mem = mem_cgroup_from_cont(cont); |
| type = MEMFILE_TYPE(event); |
| name = MEMFILE_ATTR(event); |
| switch (name) { |
| case RES_MAX_USAGE: |
| if (type == _MEM) |
| res_counter_reset_max(&mem->res); |
| else |
| res_counter_reset_max(&mem->memsw); |
| break; |
| case RES_FAILCNT: |
| if (type == _MEM) |
| res_counter_reset_failcnt(&mem->res); |
| else |
| res_counter_reset_failcnt(&mem->memsw); |
| break; |
| } |
| return 0; |
| } |
| |
| static const struct mem_cgroup_stat_desc { |
| const char *msg; |
| u64 unit; |
| } mem_cgroup_stat_desc[] = { |
| [MEM_CGROUP_STAT_CACHE] = { "cache", PAGE_SIZE, }, |
| [MEM_CGROUP_STAT_RSS] = { "rss", PAGE_SIZE, }, |
| [MEM_CGROUP_STAT_PGPGIN_COUNT] = {"pgpgin", 1, }, |
| [MEM_CGROUP_STAT_PGPGOUT_COUNT] = {"pgpgout", 1, }, |
| }; |
| |
| static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft, |
| struct cgroup_map_cb *cb) |
| { |
| struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont); |
| struct mem_cgroup_stat *stat = &mem_cont->stat; |
| int i; |
| |
| for (i = 0; i < ARRAY_SIZE(stat->cpustat[0].count); i++) { |
| s64 val; |
| |
| val = mem_cgroup_read_stat(stat, i); |
| val *= mem_cgroup_stat_desc[i].unit; |
| cb->fill(cb, mem_cgroup_stat_desc[i].msg, val); |
| } |
| /* showing # of active pages */ |
| { |
| unsigned long active_anon, inactive_anon; |
| unsigned long active_file, inactive_file; |
| unsigned long unevictable; |
| |
| inactive_anon = mem_cgroup_get_all_zonestat(mem_cont, |
| LRU_INACTIVE_ANON); |
| active_anon = mem_cgroup_get_all_zonestat(mem_cont, |
| LRU_ACTIVE_ANON); |
| inactive_file = mem_cgroup_get_all_zonestat(mem_cont, |
| LRU_INACTIVE_FILE); |
| active_file = mem_cgroup_get_all_zonestat(mem_cont, |
| LRU_ACTIVE_FILE); |
| unevictable = mem_cgroup_get_all_zonestat(mem_cont, |
| LRU_UNEVICTABLE); |
| |
| cb->fill(cb, "active_anon", (active_anon) * PAGE_SIZE); |
| cb->fill(cb, "inactive_anon", (inactive_anon) * PAGE_SIZE); |
| cb->fill(cb, "active_file", (active_file) * PAGE_SIZE); |
| cb->fill(cb, "inactive_file", (inactive_file) * PAGE_SIZE); |
| cb->fill(cb, "unevictable", unevictable * PAGE_SIZE); |
| |
| } |
| { |
| unsigned long long limit, memsw_limit; |
| memcg_get_hierarchical_limit(mem_cont, &limit, &memsw_limit); |
| cb->fill(cb, "hierarchical_memory_limit", limit); |
| if (do_swap_account) |
| cb->fill(cb, "hierarchical_memsw_limit", memsw_limit); |
| } |
| |
| #ifdef CONFIG_DEBUG_VM |
| cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL)); |
| |
| { |
| int nid, zid; |
| struct mem_cgroup_per_zone *mz; |
| unsigned long recent_rotated[2] = {0, 0}; |
| unsigned long recent_scanned[2] = {0, 0}; |
| |
| for_each_online_node(nid) |
| for (zid = 0; zid < MAX_NR_ZONES; zid++) { |
| mz = mem_cgroup_zoneinfo(mem_cont, nid, zid); |
| |
| recent_rotated[0] += |
| mz->reclaim_stat.recent_rotated[0]; |
| recent_rotated[1] += |
| mz->reclaim_stat.recent_rotated[1]; |
| recent_scanned[0] += |
| mz->reclaim_stat.recent_scanned[0]; |
| recent_scanned[1] += |
| mz->reclaim_stat.recent_scanned[1]; |
| } |
| cb->fill(cb, "recent_rotated_anon", recent_rotated[0]); |
| cb->fill(cb, "recent_rotated_file", recent_rotated[1]); |
| cb->fill(cb, "recent_scanned_anon", recent_scanned[0]); |
| cb->fill(cb, "recent_scanned_file", recent_scanned[1]); |
| } |
| #endif |
| |
| return 0; |
| } |
| |
| static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft) |
| { |
| struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
| |
| return get_swappiness(memcg); |
| } |
| |
| static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft, |
| u64 val) |
| { |
| struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
| struct mem_cgroup *parent; |
| if (val > 100) |
| return -EINVAL; |
| |
| if (cgrp->parent == NULL) |
| return -EINVAL; |
| |
| parent = mem_cgroup_from_cont(cgrp->parent); |
| /* If under hierarchy, only empty-root can set this value */ |
| if ((parent->use_hierarchy) || |
| (memcg->use_hierarchy && !list_empty(&cgrp->children))) |
| return -EINVAL; |
| |
| spin_lock(&memcg->reclaim_param_lock); |
| memcg->swappiness = val; |
| spin_unlock(&memcg->reclaim_param_lock); |
| |
| return 0; |
| } |
| |
| |
| static struct cftype mem_cgroup_files[] = { |
| { |
| .name = "usage_in_bytes", |
| .private = MEMFILE_PRIVATE(_MEM, RES_USAGE), |
| .read_u64 = mem_cgroup_read, |
| }, |
| { |
| .name = "max_usage_in_bytes", |
| .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE), |
| .trigger = mem_cgroup_reset, |
| .read_u64 = mem_cgroup_read, |
| }, |
| { |
| .name = "limit_in_bytes", |
| .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT), |
| .write_string = mem_cgroup_write, |
| .read_u64 = mem_cgroup_read, |
| }, |
| { |
| .name = "failcnt", |
| .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), |
| .trigger = mem_cgroup_reset, |
| .read_u64 = mem_cgroup_read, |
| }, |
| { |
| .name = "stat", |
| .read_map = mem_control_stat_show, |
| }, |
| { |
| .name = "force_empty", |
| .trigger = mem_cgroup_force_empty_write, |
| }, |
| { |
| .name = "use_hierarchy", |
| .write_u64 = mem_cgroup_hierarchy_write, |
| .read_u64 = mem_cgroup_hierarchy_read, |
| }, |
| { |
| .name = "swappiness", |
| .read_u64 = mem_cgroup_swappiness_read, |
| .write_u64 = mem_cgroup_swappiness_write, |
| }, |
| }; |
| |
| #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
| static struct cftype memsw_cgroup_files[] = { |
| { |
| .name = "memsw.usage_in_bytes", |
| .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), |
| .read_u64 = mem_cgroup_read, |
| }, |
| { |
| .name = "memsw.max_usage_in_bytes", |
| .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE), |
| .trigger = mem_cgroup_reset, |
| .read_u64 = mem_cgroup_read, |
| }, |
| { |
| .name = "memsw.limit_in_bytes", |
| .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT), |
| .write_string = mem_cgroup_write, |
| .read_u64 = mem_cgroup_read, |
| }, |
| { |
| .name = "memsw.failcnt", |
| .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT), |
| .trigger = mem_cgroup_reset, |
| .read_u64 = mem_cgroup_read, |
| }, |
| }; |
| |
| static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss) |
| { |
| if (!do_swap_account) |
| return 0; |
| return cgroup_add_files(cont, ss, memsw_cgroup_files, |
| ARRAY_SIZE(memsw_cgroup_files)); |
| }; |
| #else |
| static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss) |
| { |
| return 0; |
| } |
| #endif |
| |
| static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node) |
| { |
| struct mem_cgroup_per_node *pn; |
| struct mem_cgroup_per_zone *mz; |
| enum lru_list l; |
| int zone, tmp = node; |
| /* |
| * This routine is called against possible nodes. |
| * But it's BUG to call kmalloc() against offline node. |
| * |
| * TODO: this routine can waste much memory for nodes which will |
| * never be onlined. It's better to use memory hotplug callback |
| * function. |
| */ |
| if (!node_state(node, N_NORMAL_MEMORY)) |
| tmp = -1; |
| pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, tmp); |
| if (!pn) |
| return 1; |
| |
| mem->info.nodeinfo[node] = pn; |
| memset(pn, 0, sizeof(*pn)); |
| |
| for (zone = 0; zone < MAX_NR_ZONES; zone++) { |
| mz = &pn->zoneinfo[zone]; |
| for_each_lru(l) |
| INIT_LIST_HEAD(&mz->lists[l]); |
| } |
| return 0; |
| } |
| |
| static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node) |
| { |
| kfree(mem->info.nodeinfo[node]); |
| } |
| |
| static int mem_cgroup_size(void) |
| { |
| int cpustat_size = nr_cpu_ids * sizeof(struct mem_cgroup_stat_cpu); |
| return sizeof(struct mem_cgroup) + cpustat_size; |
| } |
| |
| static struct mem_cgroup *mem_cgroup_alloc(void) |
| { |
| struct mem_cgroup *mem; |
| int size = mem_cgroup_size(); |
| |
| if (size < PAGE_SIZE) |
| mem = kmalloc(size, GFP_KERNEL); |
| else |
| mem = vmalloc(size); |
| |
| if (mem) |
| memset(mem, 0, size); |
| return mem; |
| } |
| |
| /* |
| * At destroying mem_cgroup, references from swap_cgroup can remain. |
| * (scanning all at force_empty is too costly...) |
| * |
| * Instead of clearing all references at force_empty, we remember |
| * the number of reference from swap_cgroup and free mem_cgroup when |
| * it goes down to 0. |
| * |
| * Removal of cgroup itself succeeds regardless of refs from swap. |
| */ |
| |
| static void __mem_cgroup_free(struct mem_cgroup *mem) |
| { |
| int node; |
| |
| for_each_node_state(node, N_POSSIBLE) |
| free_mem_cgroup_per_zone_info(mem, node); |
| |
| if (mem_cgroup_size() < PAGE_SIZE) |
| kfree(mem); |
| else |
| vfree(mem); |
| } |
| |
| static void mem_cgroup_get(struct mem_cgroup *mem) |
| { |
| atomic_inc(&mem->refcnt); |
| } |
| |
| static void mem_cgroup_put(struct mem_cgroup *mem) |
| { |
| if (atomic_dec_and_test(&mem->refcnt)) |
| __mem_cgroup_free(mem); |
| } |
| |
| |
| #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
| static void __init enable_swap_cgroup(void) |
| { |
| if (!mem_cgroup_disabled() && really_do_swap_account) |
| do_swap_account = 1; |
| } |
| #else |
| static void __init enable_swap_cgroup(void) |
| { |
| } |
| #endif |
| |
| static struct cgroup_subsys_state * |
| mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) |
| { |
| struct mem_cgroup *mem, *parent; |
| int node; |
| |
| mem = mem_cgroup_alloc(); |
| if (!mem) |
| return ERR_PTR(-ENOMEM); |
| |
| for_each_node_state(node, N_POSSIBLE) |
| if (alloc_mem_cgroup_per_zone_info(mem, node)) |
| goto free_out; |
| /* root ? */ |
| if (cont->parent == NULL) { |
| enable_swap_cgroup(); |
| parent = NULL; |
| } else { |
| parent = mem_cgroup_from_cont(cont->parent); |
| mem->use_hierarchy = parent->use_hierarchy; |
| } |
| |
| if (parent && parent->use_hierarchy) { |
| res_counter_init(&mem->res, &parent->res); |
| res_counter_init(&mem->memsw, &parent->memsw); |
| } else { |
| res_counter_init(&mem->res, NULL); |
| res_counter_init(&mem->memsw, NULL); |
| } |
| mem->last_scanned_child = NULL; |
| spin_lock_init(&mem->reclaim_param_lock); |
| |
| if (parent) |
| mem->swappiness = get_swappiness(parent); |
| atomic_set(&mem->refcnt, 1); |
| return &mem->css; |
| free_out: |
| __mem_cgroup_free(mem); |
| return ERR_PTR(-ENOMEM); |
| } |
| |
| static void mem_cgroup_pre_destroy(struct cgroup_subsys *ss, |
| struct cgroup *cont) |
| { |
| struct mem_cgroup *mem = mem_cgroup_from_cont(cont); |
| mem_cgroup_force_empty(mem, false); |
| } |
| |
| static void mem_cgroup_destroy(struct cgroup_subsys *ss, |
| struct cgroup *cont) |
| { |
| mem_cgroup_put(mem_cgroup_from_cont(cont)); |
| } |
| |
| static int mem_cgroup_populate(struct cgroup_subsys *ss, |
| struct cgroup *cont) |
| { |
| int ret; |
| |
| ret = cgroup_add_files(cont, ss, mem_cgroup_files, |
| ARRAY_SIZE(mem_cgroup_files)); |
| |
| if (!ret) |
| ret = register_memsw_files(cont, ss); |
| return ret; |
| } |
| |
| static void mem_cgroup_move_task(struct cgroup_subsys *ss, |
| struct cgroup *cont, |
| struct cgroup *old_cont, |
| struct task_struct *p) |
| { |
| mutex_lock(&memcg_tasklist); |
| /* |
| * FIXME: It's better to move charges of this process from old |
| * memcg to new memcg. But it's just on TODO-List now. |
| */ |
| mutex_unlock(&memcg_tasklist); |
| } |
| |
| struct cgroup_subsys mem_cgroup_subsys = { |
| .name = "memory", |
| .subsys_id = mem_cgroup_subsys_id, |
| .create = mem_cgroup_create, |
| .pre_destroy = mem_cgroup_pre_destroy, |
| .destroy = mem_cgroup_destroy, |
| .populate = mem_cgroup_populate, |
| .attach = mem_cgroup_move_task, |
| .early_init = 0, |
| }; |
| |
| #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
| |
| static int __init disable_swap_account(char *s) |
| { |
| really_do_swap_account = 0; |
| return 1; |
| } |
| __setup("noswapaccount", disable_swap_account); |
| #endif |