| /* |
| * Copyright (c) 2010,2011, Dan Magenheimer, Oracle Corp. |
| * Copyright (c) 2010,2011, Nitin Gupta |
| * Copyright (c) 2011-2012, The Linux Foundation. All rights reserved. |
| * |
| * Qcache provides an in-kernel "host implementation" for transcendent memory |
| * and, thus indirectly, for cleancache and frontswap. Qcache includes a |
| * page-accessible memory [1] interface, utilizing lzo1x compression: |
| * 1) "compression buddies" ("zbud") is used for ephemeral pages |
| * Zbud allows pairs (and potentially, |
| * in the future, more than a pair of) compressed pages to be closely linked |
| * so that reclaiming can be done via the kernel's physical-page-oriented |
| * "shrinker" interface. |
| * |
| * [1] For a definition of page-accessible memory (aka PAM), see: |
| * http://marc.info/?l=linux-mm&m=127811271605009 |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/cpu.h> |
| #include <linux/highmem.h> |
| #include <linux/list.h> |
| #include <linux/lzo.h> |
| #include <linux/slab.h> |
| #include <linux/spinlock.h> |
| #include <linux/types.h> |
| #include <linux/atomic.h> |
| #include <linux/math64.h> |
| #include <linux/bitmap.h> |
| #include <linux/fmem.h> |
| #include "tmem.h" |
| |
| #if !defined(CONFIG_CLEANCACHE) |
| #error "qcache is useless without CONFIG_CLEANCACHE" |
| #endif |
| #include <linux/cleancache.h> |
| |
| #define ZCACHE_GFP_MASK \ |
| (__GFP_FS | __GFP_NORETRY | __GFP_NOWARN | __GFP_NOMEMALLOC) |
| |
| #define MAX_POOLS_PER_CLIENT 16 |
| |
| #define MAX_CLIENTS 16 |
| #define LOCAL_CLIENT ((uint16_t)-1) |
| |
| MODULE_LICENSE("GPL"); |
| |
| struct zcache_client { |
| struct tmem_pool *tmem_pools[MAX_POOLS_PER_CLIENT]; |
| struct xv_pool *xvpool; |
| bool allocated; |
| atomic_t refcount; |
| }; |
| |
| struct qcache_info { |
| void *addr; |
| unsigned long *bitmap; |
| spinlock_t lock; |
| unsigned pages; |
| }; |
| static struct qcache_info qcache_info; |
| static unsigned long zcache_qc_allocated; |
| static unsigned long zcache_qc_freed; |
| static unsigned long zcache_qc_used; |
| static unsigned long zcache_qc_max_used; |
| |
| static struct zcache_client zcache_host; |
| static struct zcache_client zcache_clients[MAX_CLIENTS]; |
| |
| static inline uint16_t get_client_id_from_client(struct zcache_client *cli) |
| { |
| BUG_ON(cli == NULL); |
| if (cli == &zcache_host) |
| return LOCAL_CLIENT; |
| return cli - &zcache_clients[0]; |
| } |
| |
| static inline bool is_local_client(struct zcache_client *cli) |
| { |
| return cli == &zcache_host; |
| } |
| |
| /********** |
| * Compression buddies ("zbud") provides for packing two (or, possibly |
| * in the future, more) compressed ephemeral pages into a single "raw" |
| * (physical) page and tracking them with data structures so that |
| * the raw pages can be easily reclaimed. |
| * |
| * A zbud page ("zbpg") is an aligned page containing a list_head, |
| * a lock, and two "zbud headers". The remainder of the physical |
| * page is divided up into aligned 64-byte "chunks" which contain |
| * the compressed data for zero, one, or two zbuds. Each zbpg |
| * resides on: (1) an "unused list" if it has no zbuds; (2) a |
| * "buddied" list if it is fully populated with two zbuds; or |
| * (3) one of PAGE_SIZE/64 "unbuddied" lists indexed by how many chunks |
| * the one unbuddied zbud uses. The data inside a zbpg cannot be |
| * read or written unless the zbpg's lock is held. |
| */ |
| |
| #define ZBH_SENTINEL 0x43214321 |
| #define ZBPG_SENTINEL 0xdeadbeef |
| |
| #define ZBUD_MAX_BUDS 2 |
| |
| struct zbud_hdr { |
| uint16_t client_id; |
| uint16_t pool_id; |
| struct tmem_oid oid; |
| uint32_t index; |
| uint16_t size; /* compressed size in bytes, zero means unused */ |
| DECL_SENTINEL |
| }; |
| |
| struct zbud_page { |
| struct list_head bud_list; |
| spinlock_t lock; |
| struct zbud_hdr buddy[ZBUD_MAX_BUDS]; |
| DECL_SENTINEL |
| /* followed by NUM_CHUNK aligned CHUNK_SIZE-byte chunks */ |
| }; |
| |
| #define CHUNK_SHIFT 6 |
| #define CHUNK_SIZE (1 << CHUNK_SHIFT) |
| #define CHUNK_MASK (~(CHUNK_SIZE-1)) |
| #define NCHUNKS (((PAGE_SIZE - sizeof(struct zbud_page)) & \ |
| CHUNK_MASK) >> CHUNK_SHIFT) |
| #define MAX_CHUNK (NCHUNKS-1) |
| |
| static struct { |
| struct list_head list; |
| unsigned count; |
| } zbud_unbuddied[NCHUNKS]; |
| /* list N contains pages with N chunks USED and NCHUNKS-N unused */ |
| /* element 0 is never used but optimizing that isn't worth it */ |
| static unsigned long zbud_cumul_chunk_counts[NCHUNKS]; |
| |
| struct list_head zbud_buddied_list; |
| static unsigned long zcache_zbud_buddied_count; |
| |
| /* protects the buddied list and all unbuddied lists */ |
| static DEFINE_SPINLOCK(zbud_budlists_spinlock); |
| |
| static atomic_t zcache_zbud_curr_raw_pages; |
| static atomic_t zcache_zbud_curr_zpages; |
| static unsigned long zcache_zbud_curr_zbytes; |
| static unsigned long zcache_zbud_cumul_zpages; |
| static unsigned long zcache_zbud_cumul_zbytes; |
| static unsigned long zcache_compress_poor; |
| static unsigned long zcache_mean_compress_poor; |
| |
| /* forward references */ |
| static void *zcache_get_free_page(void); |
| |
| static void *qcache_alloc(void) |
| { |
| void *addr; |
| unsigned long flags; |
| int offset; |
| struct qcache_info *qc = &qcache_info; |
| |
| spin_lock_irqsave(&qc->lock, flags); |
| offset = bitmap_find_free_region(qc->bitmap, qc->pages, 0); |
| |
| if (offset < 0) { |
| spin_unlock_irqrestore(&qc->lock, flags); |
| return NULL; |
| } |
| |
| zcache_qc_allocated++; |
| zcache_qc_used++; |
| zcache_qc_max_used = max(zcache_qc_max_used, zcache_qc_used); |
| spin_unlock_irqrestore(&qc->lock, flags); |
| |
| addr = qc->addr + offset * PAGE_SIZE; |
| |
| return addr; |
| } |
| |
| static void qcache_free(void *addr) |
| { |
| unsigned long flags; |
| int offset; |
| struct qcache_info *qc = &qcache_info; |
| |
| offset = (addr - qc->addr) / PAGE_SIZE; |
| |
| spin_lock_irqsave(&qc->lock, flags); |
| bitmap_release_region(qc->bitmap, offset, 0); |
| |
| zcache_qc_freed++; |
| zcache_qc_used--; |
| spin_unlock_irqrestore(&qc->lock, flags); |
| } |
| |
| /* |
| * zbud helper functions |
| */ |
| |
| static inline unsigned zbud_max_buddy_size(void) |
| { |
| return MAX_CHUNK << CHUNK_SHIFT; |
| } |
| |
| static inline unsigned zbud_size_to_chunks(unsigned size) |
| { |
| BUG_ON(size == 0 || size > zbud_max_buddy_size()); |
| return (size + CHUNK_SIZE - 1) >> CHUNK_SHIFT; |
| } |
| |
| static inline int zbud_budnum(struct zbud_hdr *zh) |
| { |
| unsigned offset = (unsigned long)zh & (PAGE_SIZE - 1); |
| struct zbud_page *zbpg = NULL; |
| unsigned budnum = -1U; |
| int i; |
| |
| for (i = 0; i < ZBUD_MAX_BUDS; i++) |
| if (offset == offsetof(typeof(*zbpg), buddy[i])) { |
| budnum = i; |
| break; |
| } |
| BUG_ON(budnum == -1U); |
| return budnum; |
| } |
| |
| static char *zbud_data(struct zbud_hdr *zh, unsigned size) |
| { |
| struct zbud_page *zbpg; |
| char *p; |
| unsigned budnum; |
| |
| ASSERT_SENTINEL(zh, ZBH); |
| budnum = zbud_budnum(zh); |
| BUG_ON(size == 0 || size > zbud_max_buddy_size()); |
| zbpg = container_of(zh, struct zbud_page, buddy[budnum]); |
| p = (char *)zbpg; |
| if (budnum == 0) |
| p += ((sizeof(struct zbud_page) + CHUNK_SIZE - 1) & |
| CHUNK_MASK); |
| else if (budnum == 1) |
| p += PAGE_SIZE - ((size + CHUNK_SIZE - 1) & CHUNK_MASK); |
| return p; |
| } |
| |
| /* |
| * zbud raw page management |
| */ |
| |
| static struct zbud_page *zbud_alloc_raw_page(void) |
| { |
| struct zbud_page *zbpg = NULL; |
| struct zbud_hdr *zh0, *zh1; |
| |
| zbpg = zcache_get_free_page(); |
| if (likely(zbpg != NULL)) { |
| INIT_LIST_HEAD(&zbpg->bud_list); |
| zh0 = &zbpg->buddy[0]; zh1 = &zbpg->buddy[1]; |
| spin_lock_init(&zbpg->lock); |
| atomic_inc(&zcache_zbud_curr_raw_pages); |
| INIT_LIST_HEAD(&zbpg->bud_list); |
| SET_SENTINEL(zbpg, ZBPG); |
| zh0->size = 0; zh1->size = 0; |
| tmem_oid_set_invalid(&zh0->oid); |
| tmem_oid_set_invalid(&zh1->oid); |
| } |
| return zbpg; |
| } |
| |
| static void zbud_free_raw_page(struct zbud_page *zbpg) |
| { |
| struct zbud_hdr *zh0 = &zbpg->buddy[0], *zh1 = &zbpg->buddy[1]; |
| |
| ASSERT_SENTINEL(zbpg, ZBPG); |
| BUG_ON(!list_empty(&zbpg->bud_list)); |
| BUG_ON(zh0->size != 0 || tmem_oid_valid(&zh0->oid)); |
| BUG_ON(zh1->size != 0 || tmem_oid_valid(&zh1->oid)); |
| INVERT_SENTINEL(zbpg, ZBPG); |
| spin_unlock(&zbpg->lock); |
| qcache_free(zbpg); |
| } |
| |
| /* |
| * core zbud handling routines |
| */ |
| |
| static unsigned zbud_free(struct zbud_hdr *zh) |
| { |
| unsigned size; |
| |
| ASSERT_SENTINEL(zh, ZBH); |
| BUG_ON(!tmem_oid_valid(&zh->oid)); |
| size = zh->size; |
| BUG_ON(zh->size == 0 || zh->size > zbud_max_buddy_size()); |
| zh->size = 0; |
| tmem_oid_set_invalid(&zh->oid); |
| INVERT_SENTINEL(zh, ZBH); |
| zcache_zbud_curr_zbytes -= size; |
| atomic_dec(&zcache_zbud_curr_zpages); |
| return size; |
| } |
| |
| static void zbud_free_and_delist(struct zbud_hdr *zh) |
| { |
| unsigned chunks; |
| struct zbud_hdr *zh_other; |
| unsigned budnum = zbud_budnum(zh), size; |
| struct zbud_page *zbpg = |
| container_of(zh, struct zbud_page, buddy[budnum]); |
| |
| spin_lock(&zbpg->lock); |
| if (list_empty(&zbpg->bud_list)) { |
| spin_unlock(&zbpg->lock); |
| return; |
| } |
| size = zbud_free(zh); |
| zh_other = &zbpg->buddy[(budnum == 0) ? 1 : 0]; |
| if (zh_other->size == 0) { /* was unbuddied: unlist and free */ |
| chunks = zbud_size_to_chunks(size) ; |
| spin_lock(&zbud_budlists_spinlock); |
| BUG_ON(list_empty(&zbud_unbuddied[chunks].list)); |
| list_del_init(&zbpg->bud_list); |
| zbud_unbuddied[chunks].count--; |
| spin_unlock(&zbud_budlists_spinlock); |
| zbud_free_raw_page(zbpg); |
| } else { /* was buddied: move remaining buddy to unbuddied list */ |
| chunks = zbud_size_to_chunks(zh_other->size) ; |
| spin_lock(&zbud_budlists_spinlock); |
| list_del_init(&zbpg->bud_list); |
| zcache_zbud_buddied_count--; |
| list_add_tail(&zbpg->bud_list, &zbud_unbuddied[chunks].list); |
| zbud_unbuddied[chunks].count++; |
| spin_unlock(&zbud_budlists_spinlock); |
| spin_unlock(&zbpg->lock); |
| } |
| } |
| |
| static struct zbud_hdr *zbud_create(uint16_t client_id, uint16_t pool_id, |
| struct tmem_oid *oid, |
| uint32_t index, struct page *page, |
| void *cdata, unsigned size) |
| { |
| struct zbud_hdr *zh0, *zh1, *zh = NULL; |
| struct zbud_page *zbpg = NULL, *ztmp; |
| unsigned nchunks; |
| char *to; |
| int i, found_good_buddy = 0; |
| |
| nchunks = zbud_size_to_chunks(size) ; |
| for (i = MAX_CHUNK - nchunks + 1; i > 0; i--) { |
| spin_lock(&zbud_budlists_spinlock); |
| if (!list_empty(&zbud_unbuddied[i].list)) { |
| list_for_each_entry_safe(zbpg, ztmp, |
| &zbud_unbuddied[i].list, bud_list) { |
| if (spin_trylock(&zbpg->lock)) { |
| found_good_buddy = i; |
| goto found_unbuddied; |
| } |
| } |
| } |
| spin_unlock(&zbud_budlists_spinlock); |
| } |
| /* didn't find a good buddy, try allocating a new page */ |
| zbpg = zbud_alloc_raw_page(); |
| if (unlikely(zbpg == NULL)) |
| goto out; |
| /* ok, have a page, now compress the data before taking locks */ |
| spin_lock(&zbpg->lock); |
| spin_lock(&zbud_budlists_spinlock); |
| list_add_tail(&zbpg->bud_list, &zbud_unbuddied[nchunks].list); |
| zbud_unbuddied[nchunks].count++; |
| zh = &zbpg->buddy[0]; |
| goto init_zh; |
| |
| found_unbuddied: |
| zh0 = &zbpg->buddy[0]; zh1 = &zbpg->buddy[1]; |
| BUG_ON(!((zh0->size == 0) ^ (zh1->size == 0))); |
| if (zh0->size != 0) { /* buddy0 in use, buddy1 is vacant */ |
| ASSERT_SENTINEL(zh0, ZBH); |
| zh = zh1; |
| } else if (zh1->size != 0) { /* buddy1 in use, buddy0 is vacant */ |
| ASSERT_SENTINEL(zh1, ZBH); |
| zh = zh0; |
| } else |
| BUG(); |
| list_del_init(&zbpg->bud_list); |
| zbud_unbuddied[found_good_buddy].count--; |
| list_add_tail(&zbpg->bud_list, &zbud_buddied_list); |
| zcache_zbud_buddied_count++; |
| |
| init_zh: |
| SET_SENTINEL(zh, ZBH); |
| zh->size = size; |
| zh->index = index; |
| zh->oid = *oid; |
| zh->pool_id = pool_id; |
| zh->client_id = client_id; |
| /* can wait to copy the data until the list locks are dropped */ |
| spin_unlock(&zbud_budlists_spinlock); |
| |
| to = zbud_data(zh, size); |
| memcpy(to, cdata, size); |
| spin_unlock(&zbpg->lock); |
| zbud_cumul_chunk_counts[nchunks]++; |
| atomic_inc(&zcache_zbud_curr_zpages); |
| zcache_zbud_cumul_zpages++; |
| zcache_zbud_curr_zbytes += size; |
| zcache_zbud_cumul_zbytes += size; |
| out: |
| return zh; |
| } |
| |
| static int zbud_decompress(struct page *page, struct zbud_hdr *zh) |
| { |
| struct zbud_page *zbpg; |
| unsigned budnum = zbud_budnum(zh); |
| size_t out_len = PAGE_SIZE; |
| char *to_va, *from_va; |
| unsigned size; |
| int ret = 0; |
| |
| zbpg = container_of(zh, struct zbud_page, buddy[budnum]); |
| spin_lock(&zbpg->lock); |
| if (list_empty(&zbpg->bud_list)) { |
| ret = -EINVAL; |
| goto out; |
| } |
| ASSERT_SENTINEL(zh, ZBH); |
| BUG_ON(zh->size == 0 || zh->size > zbud_max_buddy_size()); |
| to_va = kmap_atomic(page); |
| size = zh->size; |
| from_va = zbud_data(zh, size); |
| ret = lzo1x_decompress_safe(from_va, size, to_va, &out_len); |
| BUG_ON(ret != LZO_E_OK); |
| BUG_ON(out_len != PAGE_SIZE); |
| kunmap_atomic(to_va); |
| out: |
| spin_unlock(&zbpg->lock); |
| return ret; |
| } |
| |
| static struct tmem_pool *zcache_get_pool_by_id(uint16_t cli_id, |
| uint16_t poolid); |
| static void zcache_put_pool(struct tmem_pool *pool); |
| |
| static void zbud_init(void) |
| { |
| int i; |
| |
| INIT_LIST_HEAD(&zbud_buddied_list); |
| zcache_zbud_buddied_count = 0; |
| for (i = 0; i < NCHUNKS; i++) { |
| INIT_LIST_HEAD(&zbud_unbuddied[i].list); |
| zbud_unbuddied[i].count = 0; |
| } |
| } |
| |
| #ifdef CONFIG_SYSFS |
| /* |
| * These sysfs routines show a nice distribution of how many zbpg's are |
| * currently (and have ever been placed) in each unbuddied list. It's fun |
| * to watch but can probably go away before final merge. |
| */ |
| static int zbud_show_unbuddied_list_counts(char *buf) |
| { |
| int i; |
| char *p = buf; |
| |
| for (i = 0; i < NCHUNKS; i++) |
| p += sprintf(p, "%u ", zbud_unbuddied[i].count); |
| return p - buf; |
| } |
| |
| static int zbud_show_cumul_chunk_counts(char *buf) |
| { |
| unsigned long i, chunks = 0, total_chunks = 0, sum_total_chunks = 0; |
| unsigned long total_chunks_lte_21 = 0, total_chunks_lte_32 = 0; |
| unsigned long total_chunks_lte_42 = 0; |
| char *p = buf; |
| |
| for (i = 0; i < NCHUNKS; i++) { |
| p += sprintf(p, "%lu ", zbud_cumul_chunk_counts[i]); |
| chunks += zbud_cumul_chunk_counts[i]; |
| total_chunks += zbud_cumul_chunk_counts[i]; |
| sum_total_chunks += i * zbud_cumul_chunk_counts[i]; |
| if (i == 21) |
| total_chunks_lte_21 = total_chunks; |
| if (i == 32) |
| total_chunks_lte_32 = total_chunks; |
| if (i == 42) |
| total_chunks_lte_42 = total_chunks; |
| } |
| p += sprintf(p, "<=21:%lu <=32:%lu <=42:%lu, mean:%lu\n", |
| total_chunks_lte_21, total_chunks_lte_32, total_chunks_lte_42, |
| chunks == 0 ? 0 : sum_total_chunks / chunks); |
| return p - buf; |
| } |
| #endif |
| |
| /* |
| * zcache core code starts here |
| */ |
| |
| /* useful stats not collected by cleancache or frontswap */ |
| static unsigned long zcache_flush_total; |
| static unsigned long zcache_flush_found; |
| static unsigned long zcache_flobj_total; |
| static unsigned long zcache_flobj_found; |
| static unsigned long zcache_failed_eph_puts; |
| |
| /* |
| * Tmem operations assume the poolid implies the invoking client. |
| * Zcache only has one client (the kernel itself): LOCAL_CLIENT. |
| * RAMster has each client numbered by cluster node, and a KVM version |
| * of zcache would have one client per guest and each client might |
| * have a poolid==N. |
| */ |
| static struct tmem_pool *zcache_get_pool_by_id(uint16_t cli_id, uint16_t poolid) |
| { |
| struct tmem_pool *pool = NULL; |
| struct zcache_client *cli = NULL; |
| |
| if (cli_id == LOCAL_CLIENT) |
| cli = &zcache_host; |
| else { |
| if (cli_id >= MAX_CLIENTS) |
| goto out; |
| cli = &zcache_clients[cli_id]; |
| if (cli == NULL) |
| goto out; |
| atomic_inc(&cli->refcount); |
| } |
| if (poolid < MAX_POOLS_PER_CLIENT) { |
| pool = cli->tmem_pools[poolid]; |
| if (pool != NULL) |
| atomic_inc(&pool->refcount); |
| } |
| out: |
| return pool; |
| } |
| |
| static void zcache_put_pool(struct tmem_pool *pool) |
| { |
| struct zcache_client *cli = NULL; |
| |
| if (pool == NULL) |
| BUG(); |
| cli = pool->client; |
| atomic_dec(&pool->refcount); |
| atomic_dec(&cli->refcount); |
| } |
| |
| int zcache_new_client(uint16_t cli_id) |
| { |
| struct zcache_client *cli = NULL; |
| int ret = -1; |
| |
| if (cli_id == LOCAL_CLIENT) |
| cli = &zcache_host; |
| else if ((unsigned int)cli_id < MAX_CLIENTS) |
| cli = &zcache_clients[cli_id]; |
| if (cli == NULL) |
| goto out; |
| if (cli->allocated) |
| goto out; |
| cli->allocated = 1; |
| ret = 0; |
| out: |
| return ret; |
| } |
| |
| /* counters for debugging */ |
| static unsigned long zcache_failed_get_free_pages; |
| static unsigned long zcache_failed_alloc; |
| static unsigned long zcache_put_to_flush; |
| static unsigned long zcache_aborted_preload; |
| static unsigned long zcache_aborted_shrink; |
| |
| /* |
| * Ensure that memory allocation requests in zcache don't result |
| * in direct reclaim requests via the shrinker, which would cause |
| * an infinite loop. Maybe a GFP flag would be better? |
| */ |
| static DEFINE_SPINLOCK(zcache_direct_reclaim_lock); |
| |
| /* |
| * for now, used named slabs so can easily track usage; later can |
| * either just use kmalloc, or perhaps add a slab-like allocator |
| * to more carefully manage total memory utilization |
| */ |
| static struct kmem_cache *zcache_objnode_cache; |
| static struct kmem_cache *zcache_obj_cache; |
| static atomic_t zcache_curr_obj_count = ATOMIC_INIT(0); |
| static unsigned long zcache_curr_obj_count_max; |
| static atomic_t zcache_curr_objnode_count = ATOMIC_INIT(0); |
| static unsigned long zcache_curr_objnode_count_max; |
| |
| /* |
| * to avoid memory allocation recursion (e.g. due to direct reclaim), we |
| * preload all necessary data structures so the hostops callbacks never |
| * actually do a malloc |
| */ |
| struct zcache_preload { |
| void *page; |
| struct tmem_obj *obj; |
| int nr; |
| struct tmem_objnode *objnodes[OBJNODE_TREE_MAX_PATH]; |
| }; |
| static DEFINE_PER_CPU(struct zcache_preload, zcache_preloads) = { 0, }; |
| |
| static int zcache_do_preload(struct tmem_pool *pool) |
| { |
| struct zcache_preload *kp; |
| struct tmem_objnode *objnode; |
| struct tmem_obj *obj; |
| void *page; |
| int ret = -ENOMEM; |
| |
| if (unlikely(zcache_objnode_cache == NULL)) |
| goto out; |
| if (unlikely(zcache_obj_cache == NULL)) |
| goto out; |
| if (!spin_trylock(&zcache_direct_reclaim_lock)) { |
| zcache_aborted_preload++; |
| goto out; |
| } |
| preempt_disable(); |
| kp = &__get_cpu_var(zcache_preloads); |
| while (kp->nr < ARRAY_SIZE(kp->objnodes)) { |
| preempt_enable_no_resched(); |
| objnode = kmem_cache_alloc(zcache_objnode_cache, |
| ZCACHE_GFP_MASK); |
| if (unlikely(objnode == NULL)) { |
| zcache_failed_alloc++; |
| goto unlock_out; |
| } |
| preempt_disable(); |
| kp = &__get_cpu_var(zcache_preloads); |
| if (kp->nr < ARRAY_SIZE(kp->objnodes)) |
| kp->objnodes[kp->nr++] = objnode; |
| else |
| kmem_cache_free(zcache_objnode_cache, objnode); |
| } |
| preempt_enable_no_resched(); |
| obj = kmem_cache_alloc(zcache_obj_cache, ZCACHE_GFP_MASK); |
| if (unlikely(obj == NULL)) { |
| zcache_failed_alloc++; |
| goto unlock_out; |
| } |
| page = qcache_alloc(); |
| if (unlikely(page == NULL)) { |
| zcache_failed_get_free_pages++; |
| kmem_cache_free(zcache_obj_cache, obj); |
| goto unlock_out; |
| } |
| preempt_disable(); |
| kp = &__get_cpu_var(zcache_preloads); |
| if (kp->obj == NULL) |
| kp->obj = obj; |
| else |
| kmem_cache_free(zcache_obj_cache, obj); |
| if (kp->page == NULL) |
| kp->page = page; |
| else |
| qcache_free(page); |
| ret = 0; |
| unlock_out: |
| spin_unlock(&zcache_direct_reclaim_lock); |
| out: |
| return ret; |
| } |
| |
| static void *zcache_get_free_page(void) |
| { |
| struct zcache_preload *kp; |
| void *page; |
| |
| kp = &__get_cpu_var(zcache_preloads); |
| page = kp->page; |
| BUG_ON(page == NULL); |
| kp->page = NULL; |
| return page; |
| } |
| |
| /* |
| * zcache implementation for tmem host ops |
| */ |
| |
| static struct tmem_objnode *zcache_objnode_alloc(struct tmem_pool *pool) |
| { |
| struct tmem_objnode *objnode = NULL; |
| unsigned long count; |
| struct zcache_preload *kp; |
| |
| kp = &__get_cpu_var(zcache_preloads); |
| if (kp->nr <= 0) |
| goto out; |
| objnode = kp->objnodes[kp->nr - 1]; |
| BUG_ON(objnode == NULL); |
| kp->objnodes[kp->nr - 1] = NULL; |
| kp->nr--; |
| count = atomic_inc_return(&zcache_curr_objnode_count); |
| if (count > zcache_curr_objnode_count_max) |
| zcache_curr_objnode_count_max = count; |
| out: |
| return objnode; |
| } |
| |
| static void zcache_objnode_free(struct tmem_objnode *objnode, |
| struct tmem_pool *pool) |
| { |
| atomic_dec(&zcache_curr_objnode_count); |
| BUG_ON(atomic_read(&zcache_curr_objnode_count) < 0); |
| kmem_cache_free(zcache_objnode_cache, objnode); |
| } |
| |
| static struct tmem_obj *zcache_obj_alloc(struct tmem_pool *pool) |
| { |
| struct tmem_obj *obj = NULL; |
| unsigned long count; |
| struct zcache_preload *kp; |
| |
| kp = &__get_cpu_var(zcache_preloads); |
| obj = kp->obj; |
| BUG_ON(obj == NULL); |
| kp->obj = NULL; |
| count = atomic_inc_return(&zcache_curr_obj_count); |
| if (count > zcache_curr_obj_count_max) |
| zcache_curr_obj_count_max = count; |
| return obj; |
| } |
| |
| static void zcache_obj_free(struct tmem_obj *obj, struct tmem_pool *pool) |
| { |
| atomic_dec(&zcache_curr_obj_count); |
| BUG_ON(atomic_read(&zcache_curr_obj_count) < 0); |
| kmem_cache_free(zcache_obj_cache, obj); |
| } |
| |
| static void zcache_flush_all_obj(void) |
| { |
| struct tmem_pool *pool; |
| int pool_id; |
| struct zcache_preload *kp; |
| |
| kp = &__get_cpu_var(zcache_preloads); |
| |
| for (pool_id = 0; pool_id < MAX_POOLS_PER_CLIENT; pool_id++) { |
| pool = zcache_get_pool_by_id(LOCAL_CLIENT, pool_id); |
| tmem_flush_pool(pool); |
| if (pool) |
| zcache_put_pool(pool); |
| } |
| if (kp->page) { |
| qcache_free(kp->page); |
| kp->page = NULL; |
| } |
| if (zcache_qc_used) |
| pr_warn("pages used not 0 after qcache flush all, is %ld\n", |
| zcache_qc_used); |
| } |
| |
| /* |
| * When zcache is disabled ("frozen"), pools can be created and destroyed, |
| * but all puts (and thus all other operations that require memory allocation) |
| * must fail. If zcache is unfrozen, accepts puts, then frozen again, |
| * data consistency requires all puts while frozen to be converted into |
| * flushes. |
| */ |
| static bool zcache_freeze; |
| |
| static void zcache_control(bool freeze) |
| { |
| zcache_freeze = freeze; |
| } |
| |
| static struct tmem_hostops zcache_hostops = { |
| .obj_alloc = zcache_obj_alloc, |
| .obj_free = zcache_obj_free, |
| .objnode_alloc = zcache_objnode_alloc, |
| .objnode_free = zcache_objnode_free, |
| .flush_all_obj = zcache_flush_all_obj, |
| .control = zcache_control, |
| }; |
| |
| /* |
| * zcache implementations for PAM page descriptor ops |
| */ |
| |
| static atomic_t zcache_curr_eph_pampd_count = ATOMIC_INIT(0); |
| static unsigned long zcache_curr_eph_pampd_count_max; |
| |
| /* forward reference */ |
| static int zcache_compress(struct page *from, void **out_va, size_t *out_len); |
| |
| static void *zcache_pampd_create(char *data, size_t size, bool raw, int eph, |
| struct tmem_pool *pool, struct tmem_oid *oid, |
| uint32_t index) |
| { |
| void *pampd = NULL, *cdata; |
| size_t clen; |
| int ret; |
| unsigned long count; |
| struct page *page = (struct page *)(data); |
| struct zcache_client *cli = pool->client; |
| uint16_t client_id = get_client_id_from_client(cli); |
| |
| ret = zcache_compress(page, &cdata, &clen); |
| if (ret == 0) |
| goto out; |
| if (clen == 0 || clen > zbud_max_buddy_size()) { |
| zcache_compress_poor++; |
| goto out; |
| } |
| pampd = (void *)zbud_create(client_id, pool->pool_id, oid, |
| index, page, cdata, clen); |
| if (pampd != NULL) { |
| count = atomic_inc_return(&zcache_curr_eph_pampd_count); |
| if (count > zcache_curr_eph_pampd_count_max) |
| zcache_curr_eph_pampd_count_max = count; |
| } |
| out: |
| return pampd; |
| } |
| |
| /* |
| * fill the pageframe corresponding to the struct page with the data |
| * from the passed pampd |
| */ |
| static int zcache_pampd_get_data(char *data, size_t *bufsize, bool raw, |
| void *pampd, struct tmem_pool *pool, |
| struct tmem_oid *oid, uint32_t index) |
| { |
| BUG(); |
| return 0; |
| } |
| |
| /* |
| * fill the pageframe corresponding to the struct page with the data |
| * from the passed pampd |
| */ |
| static int zcache_pampd_get_data_and_free(char *data, size_t *bufsize, bool raw, |
| void *pampd, struct tmem_pool *pool, |
| struct tmem_oid *oid, uint32_t index) |
| { |
| int ret = 0; |
| |
| zbud_decompress((struct page *)(data), pampd); |
| zbud_free_and_delist((struct zbud_hdr *)pampd); |
| atomic_dec(&zcache_curr_eph_pampd_count); |
| return ret; |
| } |
| |
| /* |
| * free the pampd and remove it from any zcache lists |
| * pampd must no longer be pointed to from any tmem data structures! |
| */ |
| static void zcache_pampd_free(void *pampd, struct tmem_pool *pool, |
| struct tmem_oid *oid, uint32_t index) |
| { |
| zbud_free_and_delist((struct zbud_hdr *)pampd); |
| atomic_dec(&zcache_curr_eph_pampd_count); |
| BUG_ON(atomic_read(&zcache_curr_eph_pampd_count) < 0); |
| } |
| |
| static void zcache_pampd_free_obj(struct tmem_pool *pool, struct tmem_obj *obj) |
| { |
| } |
| |
| static void zcache_pampd_new_obj(struct tmem_obj *obj) |
| { |
| } |
| |
| static int zcache_pampd_replace_in_obj(void *pampd, struct tmem_obj *obj) |
| { |
| return -1; |
| } |
| |
| static bool zcache_pampd_is_remote(void *pampd) |
| { |
| return 0; |
| } |
| |
| static struct tmem_pamops zcache_pamops = { |
| .create = zcache_pampd_create, |
| .get_data = zcache_pampd_get_data, |
| .get_data_and_free = zcache_pampd_get_data_and_free, |
| .free = zcache_pampd_free, |
| .free_obj = zcache_pampd_free_obj, |
| .new_obj = zcache_pampd_new_obj, |
| .replace_in_obj = zcache_pampd_replace_in_obj, |
| .is_remote = zcache_pampd_is_remote, |
| }; |
| |
| /* |
| * zcache compression/decompression and related per-cpu stuff |
| */ |
| |
| #define LZO_WORKMEM_BYTES LZO1X_1_MEM_COMPRESS |
| #define LZO_DSTMEM_PAGE_ORDER 1 |
| static DEFINE_PER_CPU(unsigned char *, zcache_workmem); |
| static DEFINE_PER_CPU(unsigned char *, zcache_dstmem); |
| |
| static int zcache_compress(struct page *from, void **out_va, size_t *out_len) |
| { |
| int ret = 0; |
| unsigned char *dmem = __get_cpu_var(zcache_dstmem); |
| unsigned char *wmem = __get_cpu_var(zcache_workmem); |
| char *from_va; |
| |
| BUG_ON(!irqs_disabled()); |
| if (unlikely(dmem == NULL || wmem == NULL)) |
| goto out; /* no buffer, so can't compress */ |
| from_va = kmap_atomic(from); |
| mb(); |
| ret = lzo1x_1_compress(from_va, PAGE_SIZE, dmem, out_len, wmem); |
| BUG_ON(ret != LZO_E_OK); |
| *out_va = dmem; |
| kunmap_atomic(from_va); |
| ret = 1; |
| out: |
| return ret; |
| } |
| |
| #ifdef CONFIG_SYSFS |
| #define ZCACHE_SYSFS_RO(_name) \ |
| static ssize_t zcache_##_name##_show(struct kobject *kobj, \ |
| struct kobj_attribute *attr, char *buf) \ |
| { \ |
| return sprintf(buf, "%lu\n", zcache_##_name); \ |
| } \ |
| static struct kobj_attribute zcache_##_name##_attr = { \ |
| .attr = { .name = __stringify(_name), .mode = 0444 }, \ |
| .show = zcache_##_name##_show, \ |
| } |
| |
| #define ZCACHE_SYSFS_RO_ATOMIC(_name) \ |
| static ssize_t zcache_##_name##_show(struct kobject *kobj, \ |
| struct kobj_attribute *attr, char *buf) \ |
| { \ |
| return sprintf(buf, "%d\n", atomic_read(&zcache_##_name)); \ |
| } \ |
| static struct kobj_attribute zcache_##_name##_attr = { \ |
| .attr = { .name = __stringify(_name), .mode = 0444 }, \ |
| .show = zcache_##_name##_show, \ |
| } |
| |
| #define ZCACHE_SYSFS_RO_CUSTOM(_name, _func) \ |
| static ssize_t zcache_##_name##_show(struct kobject *kobj, \ |
| struct kobj_attribute *attr, char *buf) \ |
| { \ |
| return _func(buf); \ |
| } \ |
| static struct kobj_attribute zcache_##_name##_attr = { \ |
| .attr = { .name = __stringify(_name), .mode = 0444 }, \ |
| .show = zcache_##_name##_show, \ |
| } |
| |
| ZCACHE_SYSFS_RO(curr_obj_count_max); |
| ZCACHE_SYSFS_RO(curr_objnode_count_max); |
| ZCACHE_SYSFS_RO(flush_total); |
| ZCACHE_SYSFS_RO(flush_found); |
| ZCACHE_SYSFS_RO(flobj_total); |
| ZCACHE_SYSFS_RO(flobj_found); |
| ZCACHE_SYSFS_RO(failed_eph_puts); |
| ZCACHE_SYSFS_RO(zbud_curr_zbytes); |
| ZCACHE_SYSFS_RO(zbud_cumul_zpages); |
| ZCACHE_SYSFS_RO(zbud_cumul_zbytes); |
| ZCACHE_SYSFS_RO(zbud_buddied_count); |
| ZCACHE_SYSFS_RO(failed_get_free_pages); |
| ZCACHE_SYSFS_RO(failed_alloc); |
| ZCACHE_SYSFS_RO(put_to_flush); |
| ZCACHE_SYSFS_RO(aborted_preload); |
| ZCACHE_SYSFS_RO(aborted_shrink); |
| ZCACHE_SYSFS_RO(compress_poor); |
| ZCACHE_SYSFS_RO(mean_compress_poor); |
| ZCACHE_SYSFS_RO(qc_allocated); |
| ZCACHE_SYSFS_RO(qc_freed); |
| ZCACHE_SYSFS_RO(qc_used); |
| ZCACHE_SYSFS_RO(qc_max_used); |
| ZCACHE_SYSFS_RO_ATOMIC(zbud_curr_raw_pages); |
| ZCACHE_SYSFS_RO_ATOMIC(zbud_curr_zpages); |
| ZCACHE_SYSFS_RO_ATOMIC(curr_obj_count); |
| ZCACHE_SYSFS_RO_ATOMIC(curr_objnode_count); |
| ZCACHE_SYSFS_RO_CUSTOM(zbud_unbuddied_list_counts, |
| zbud_show_unbuddied_list_counts); |
| ZCACHE_SYSFS_RO_CUSTOM(zbud_cumul_chunk_counts, |
| zbud_show_cumul_chunk_counts); |
| |
| static struct attribute *qcache_attrs[] = { |
| &zcache_curr_obj_count_attr.attr, |
| &zcache_curr_obj_count_max_attr.attr, |
| &zcache_curr_objnode_count_attr.attr, |
| &zcache_curr_objnode_count_max_attr.attr, |
| &zcache_flush_total_attr.attr, |
| &zcache_flobj_total_attr.attr, |
| &zcache_flush_found_attr.attr, |
| &zcache_flobj_found_attr.attr, |
| &zcache_failed_eph_puts_attr.attr, |
| &zcache_compress_poor_attr.attr, |
| &zcache_mean_compress_poor_attr.attr, |
| &zcache_zbud_curr_raw_pages_attr.attr, |
| &zcache_zbud_curr_zpages_attr.attr, |
| &zcache_zbud_curr_zbytes_attr.attr, |
| &zcache_zbud_cumul_zpages_attr.attr, |
| &zcache_zbud_cumul_zbytes_attr.attr, |
| &zcache_zbud_buddied_count_attr.attr, |
| &zcache_failed_get_free_pages_attr.attr, |
| &zcache_failed_alloc_attr.attr, |
| &zcache_put_to_flush_attr.attr, |
| &zcache_aborted_preload_attr.attr, |
| &zcache_aborted_shrink_attr.attr, |
| &zcache_zbud_unbuddied_list_counts_attr.attr, |
| &zcache_zbud_cumul_chunk_counts_attr.attr, |
| &zcache_qc_allocated_attr.attr, |
| &zcache_qc_freed_attr.attr, |
| &zcache_qc_used_attr.attr, |
| &zcache_qc_max_used_attr.attr, |
| NULL, |
| }; |
| |
| static struct attribute_group qcache_attr_group = { |
| .attrs = qcache_attrs, |
| .name = "qcache", |
| }; |
| |
| #endif /* CONFIG_SYSFS */ |
| |
| /* |
| * zcache shims between cleancache ops and tmem |
| */ |
| |
| static int zcache_put_page(int cli_id, int pool_id, struct tmem_oid *oidp, |
| uint32_t index, struct page *page) |
| { |
| struct tmem_pool *pool; |
| int ret = -1; |
| |
| BUG_ON(!irqs_disabled()); |
| pool = zcache_get_pool_by_id(cli_id, pool_id); |
| if (unlikely(pool == NULL)) |
| goto out; |
| if (!zcache_freeze && zcache_do_preload(pool) == 0) { |
| /* preload does preempt_disable on success */ |
| ret = tmem_put(pool, oidp, index, (char *)(page), |
| PAGE_SIZE, 0, is_ephemeral(pool)); |
| if (ret < 0) { |
| zcache_failed_eph_puts++; |
| } |
| zcache_put_pool(pool); |
| preempt_enable_no_resched(); |
| } else { |
| zcache_put_to_flush++; |
| if (atomic_read(&pool->obj_count) > 0) |
| /* the put fails whether the flush succeeds or not */ |
| (void)tmem_flush_page(pool, oidp, index); |
| zcache_put_pool(pool); |
| } |
| out: |
| return ret; |
| } |
| |
| static int zcache_get_page(int cli_id, int pool_id, struct tmem_oid *oidp, |
| uint32_t index, struct page *page) |
| { |
| struct tmem_pool *pool; |
| int ret = -1; |
| unsigned long flags; |
| size_t size = PAGE_SIZE; |
| |
| local_irq_save(flags); |
| pool = zcache_get_pool_by_id(cli_id, pool_id); |
| if (likely(pool != NULL)) { |
| if (atomic_read(&pool->obj_count) > 0) |
| ret = tmem_get(pool, oidp, index, (char *)(page), |
| &size, 0, is_ephemeral(pool)); |
| zcache_put_pool(pool); |
| } |
| local_irq_restore(flags); |
| return ret; |
| } |
| |
| static int zcache_flush_page(int cli_id, int pool_id, |
| struct tmem_oid *oidp, uint32_t index) |
| { |
| struct tmem_pool *pool; |
| int ret = -1; |
| unsigned long flags; |
| |
| local_irq_save(flags); |
| zcache_flush_total++; |
| pool = zcache_get_pool_by_id(cli_id, pool_id); |
| if (likely(pool != NULL)) { |
| if (atomic_read(&pool->obj_count) > 0) |
| ret = tmem_flush_page(pool, oidp, index); |
| zcache_put_pool(pool); |
| } |
| if (ret >= 0) |
| zcache_flush_found++; |
| local_irq_restore(flags); |
| return ret; |
| } |
| |
| static int zcache_flush_object(int cli_id, int pool_id, |
| struct tmem_oid *oidp) |
| { |
| struct tmem_pool *pool; |
| int ret = -1; |
| unsigned long flags; |
| |
| local_irq_save(flags); |
| zcache_flobj_total++; |
| pool = zcache_get_pool_by_id(cli_id, pool_id); |
| if (likely(pool != NULL)) { |
| if (atomic_read(&pool->obj_count) > 0) |
| ret = tmem_flush_object(pool, oidp); |
| zcache_put_pool(pool); |
| } |
| if (ret >= 0) |
| zcache_flobj_found++; |
| local_irq_restore(flags); |
| return ret; |
| } |
| |
| static int zcache_destroy_pool(int cli_id, int pool_id) |
| { |
| struct tmem_pool *pool = NULL; |
| struct zcache_client *cli = NULL; |
| int ret = -1; |
| |
| if (pool_id < 0) |
| goto out; |
| if (cli_id == LOCAL_CLIENT) |
| cli = &zcache_host; |
| else if ((unsigned int)cli_id < MAX_CLIENTS) |
| cli = &zcache_clients[cli_id]; |
| if (cli == NULL) |
| goto out; |
| atomic_inc(&cli->refcount); |
| pool = cli->tmem_pools[pool_id]; |
| if (pool == NULL) |
| goto out; |
| cli->tmem_pools[pool_id] = NULL; |
| /* wait for pool activity on other cpus to quiesce */ |
| while (atomic_read(&pool->refcount) != 0) |
| ; |
| atomic_dec(&cli->refcount); |
| local_bh_disable(); |
| ret = tmem_destroy_pool(pool); |
| local_bh_enable(); |
| kfree(pool); |
| pr_info("qcache: destroyed pool id=%d, cli_id=%d\n", |
| pool_id, cli_id); |
| out: |
| return ret; |
| } |
| |
| static int zcache_new_pool(uint16_t cli_id, uint32_t flags) |
| { |
| int poolid = -1; |
| struct tmem_pool *pool; |
| struct zcache_client *cli = NULL; |
| |
| if (cli_id == LOCAL_CLIENT) |
| cli = &zcache_host; |
| else if ((unsigned int)cli_id < MAX_CLIENTS) |
| cli = &zcache_clients[cli_id]; |
| if (cli == NULL) |
| goto out; |
| atomic_inc(&cli->refcount); |
| pool = kmalloc(sizeof(struct tmem_pool), GFP_KERNEL); |
| if (pool == NULL) { |
| pr_info("qcache: pool creation failed: out of memory\n"); |
| goto out; |
| } |
| |
| for (poolid = 0; poolid < MAX_POOLS_PER_CLIENT; poolid++) |
| if (cli->tmem_pools[poolid] == NULL) |
| break; |
| if (poolid >= MAX_POOLS_PER_CLIENT) { |
| pr_info("qcache: pool creation failed: max exceeded\n"); |
| kfree(pool); |
| poolid = -1; |
| goto out; |
| } |
| atomic_set(&pool->refcount, 0); |
| pool->client = cli; |
| pool->pool_id = poolid; |
| tmem_new_pool(pool, flags); |
| cli->tmem_pools[poolid] = pool; |
| pr_info("qcache: created %s tmem pool, id=%d, client=%d\n", |
| flags & TMEM_POOL_PERSIST ? "persistent" : "ephemeral", |
| poolid, cli_id); |
| out: |
| if (cli != NULL) |
| atomic_dec(&cli->refcount); |
| return poolid; |
| } |
| |
| /********** |
| * Two kernel functionalities currently can be layered on top of tmem. |
| * These are "cleancache" which is used as a second-chance cache for clean |
| * page cache pages; and "frontswap" which is used for swap pages |
| * to avoid writes to disk. A generic "shim" is provided here for each |
| * to translate in-kernel semantics to zcache semantics. |
| */ |
| |
| static void zcache_cleancache_put_page(int pool_id, |
| struct cleancache_filekey key, |
| pgoff_t index, struct page *page) |
| { |
| u32 ind = (u32) index; |
| struct tmem_oid oid = *(struct tmem_oid *)&key; |
| |
| if (likely(ind == index)) |
| (void)zcache_put_page(LOCAL_CLIENT, pool_id, &oid, index, page); |
| } |
| |
| static int zcache_cleancache_get_page(int pool_id, |
| struct cleancache_filekey key, |
| pgoff_t index, struct page *page) |
| { |
| u32 ind = (u32) index; |
| struct tmem_oid oid = *(struct tmem_oid *)&key; |
| int ret = -1; |
| |
| if (likely(ind == index)) |
| ret = zcache_get_page(LOCAL_CLIENT, pool_id, &oid, index, page); |
| return ret; |
| } |
| |
| static void zcache_cleancache_flush_page(int pool_id, |
| struct cleancache_filekey key, |
| pgoff_t index) |
| { |
| u32 ind = (u32) index; |
| struct tmem_oid oid = *(struct tmem_oid *)&key; |
| |
| if (likely(ind == index)) |
| (void)zcache_flush_page(LOCAL_CLIENT, pool_id, &oid, ind); |
| } |
| |
| static void zcache_cleancache_flush_inode(int pool_id, |
| struct cleancache_filekey key) |
| { |
| struct tmem_oid oid = *(struct tmem_oid *)&key; |
| |
| (void)zcache_flush_object(LOCAL_CLIENT, pool_id, &oid); |
| } |
| |
| static void zcache_cleancache_flush_fs(int pool_id) |
| { |
| if (pool_id >= 0) |
| (void)zcache_destroy_pool(LOCAL_CLIENT, pool_id); |
| } |
| |
| static int zcache_cleancache_init_fs(size_t pagesize) |
| { |
| BUG_ON(sizeof(struct cleancache_filekey) != |
| sizeof(struct tmem_oid)); |
| BUG_ON(pagesize != PAGE_SIZE); |
| return zcache_new_pool(LOCAL_CLIENT, 0); |
| } |
| |
| static int zcache_cleancache_init_shared_fs(char *uuid, size_t pagesize) |
| { |
| /* shared pools are unsupported and map to private */ |
| BUG_ON(sizeof(struct cleancache_filekey) != |
| sizeof(struct tmem_oid)); |
| BUG_ON(pagesize != PAGE_SIZE); |
| return zcache_new_pool(LOCAL_CLIENT, 0); |
| } |
| |
| static struct cleancache_ops zcache_cleancache_ops = { |
| .put_page = zcache_cleancache_put_page, |
| .get_page = zcache_cleancache_get_page, |
| .invalidate_page = zcache_cleancache_flush_page, |
| .invalidate_inode = zcache_cleancache_flush_inode, |
| .invalidate_fs = zcache_cleancache_flush_fs, |
| .init_shared_fs = zcache_cleancache_init_shared_fs, |
| .init_fs = zcache_cleancache_init_fs |
| }; |
| |
| struct cleancache_ops zcache_cleancache_register_ops(void) |
| { |
| struct cleancache_ops old_ops = |
| cleancache_register_ops(&zcache_cleancache_ops); |
| |
| return old_ops; |
| } |
| |
| static int __init qcache_init(void) |
| { |
| int ret = 0; |
| struct qcache_info *qc = &qcache_info; |
| struct fmem_data *fdp; |
| int bitmap_size; |
| unsigned int cpu; |
| struct cleancache_ops old_ops; |
| |
| #ifdef CONFIG_SYSFS |
| ret = sysfs_create_group(mm_kobj, &qcache_attr_group); |
| if (ret) { |
| pr_err("qcache: can't create sysfs\n"); |
| goto out; |
| } |
| #endif /* CONFIG_SYSFS */ |
| |
| fdp = fmem_get_info(); |
| qc->addr = fdp->virt; |
| qc->pages = fdp->size >> PAGE_SHIFT; |
| if (!qc->pages) |
| goto out; |
| |
| tmem_register_hostops(&zcache_hostops); |
| tmem_register_pamops(&zcache_pamops); |
| for_each_online_cpu(cpu) { |
| per_cpu(zcache_dstmem, cpu) = (void *)__get_free_pages( |
| GFP_KERNEL | __GFP_REPEAT, |
| LZO_DSTMEM_PAGE_ORDER), |
| per_cpu(zcache_workmem, cpu) = |
| kzalloc(LZO1X_MEM_COMPRESS, |
| GFP_KERNEL | __GFP_REPEAT); |
| } |
| zcache_objnode_cache = kmem_cache_create("zcache_objnode", |
| sizeof(struct tmem_objnode), 0, 0, NULL); |
| zcache_obj_cache = kmem_cache_create("zcache_obj", |
| sizeof(struct tmem_obj), 0, 0, NULL); |
| ret = zcache_new_client(LOCAL_CLIENT); |
| if (ret) { |
| pr_err("qcache: can't create client\n"); |
| goto out; |
| } |
| |
| zbud_init(); |
| old_ops = zcache_cleancache_register_ops(); |
| pr_info("qcache: cleancache enabled using kernel " |
| "transcendent memory and compression buddies\n"); |
| if (old_ops.init_fs != NULL) |
| pr_warning("qcache: cleancache_ops overridden"); |
| |
| |
| bitmap_size = BITS_TO_LONGS(qc->pages) * sizeof(long); |
| |
| qc->bitmap = kzalloc(bitmap_size, GFP_KERNEL); |
| if (!qc->bitmap) { |
| pr_info("can't allocate qcache bitmap!\n"); |
| ret = -ENOMEM; |
| goto out; |
| } |
| spin_lock_init(&qc->lock); |
| |
| fmem_set_state(FMEM_T_STATE); |
| |
| out: |
| return ret; |
| } |
| |
| module_init(qcache_init) |