diff --git a/drivers/staging/zcache/tmem.c b/drivers/staging/zcache/tmem.c index e954d405b138..975e34bcd722 100644 --- a/drivers/staging/zcache/tmem.c +++ b/drivers/staging/zcache/tmem.c @@ -142,6 +142,7 @@ static void tmem_obj_init(struct tmem_obj *obj, struct tmem_hashbucket *hb, obj->oid = *oidp; obj->objnode_count = 0; obj->pampd_count = 0; + (*tmem_pamops.new_obj)(obj); SET_SENTINEL(obj, OBJ); while (*new) { BUG_ON(RB_EMPTY_NODE(*new)); @@ -274,7 +275,7 @@ static void tmem_objnode_free(struct tmem_objnode *objnode) /* * lookup index in object and return associated pampd (or NULL if not found) */ -static void *tmem_pampd_lookup_in_obj(struct tmem_obj *obj, uint32_t index) +static void **__tmem_pampd_lookup_in_obj(struct tmem_obj *obj, uint32_t index) { unsigned int height, shift; struct tmem_objnode **slot = NULL; @@ -303,9 +304,33 @@ static void *tmem_pampd_lookup_in_obj(struct tmem_obj *obj, uint32_t index) height--; } out: + return slot != NULL ? (void **)slot : NULL; +} + +static void *tmem_pampd_lookup_in_obj(struct tmem_obj *obj, uint32_t index) +{ + struct tmem_objnode **slot; + + slot = (struct tmem_objnode **)__tmem_pampd_lookup_in_obj(obj, index); return slot != NULL ? *slot : NULL; } +static void *tmem_pampd_replace_in_obj(struct tmem_obj *obj, uint32_t index, + void *new_pampd) +{ + struct tmem_objnode **slot; + void *ret = NULL; + + slot = (struct tmem_objnode **)__tmem_pampd_lookup_in_obj(obj, index); + if ((slot != NULL) && (*slot != NULL)) { + void *old_pampd = *(void **)slot; + *(void **)slot = new_pampd; + (*tmem_pamops.free)(old_pampd, obj->pool, NULL, 0); + ret = new_pampd; + } + return ret; +} + static int tmem_pampd_add_to_obj(struct tmem_obj *obj, uint32_t index, void *pampd) { @@ -456,7 +481,7 @@ static void tmem_objnode_node_destroy(struct tmem_obj *obj, if (ht == 1) { obj->pampd_count--; (*tmem_pamops.free)(objnode->slots[i], - obj->pool); + obj->pool, NULL, 0); objnode->slots[i] = NULL; continue; } @@ -473,7 +498,7 @@ static void tmem_pampd_destroy_all_in_obj(struct tmem_obj *obj) return; if (obj->objnode_tree_height == 0) { obj->pampd_count--; - (*tmem_pamops.free)(obj->objnode_tree_root, obj->pool); + (*tmem_pamops.free)(obj->objnode_tree_root, obj->pool, NULL, 0); } else { tmem_objnode_node_destroy(obj, obj->objnode_tree_root, obj->objnode_tree_height); @@ -481,6 +506,7 @@ static void tmem_pampd_destroy_all_in_obj(struct tmem_obj *obj) obj->objnode_tree_height = 0; } obj->objnode_tree_root = NULL; + (*tmem_pamops.free_obj)(obj->pool, obj); } /* @@ -503,15 +529,13 @@ static void tmem_pampd_destroy_all_in_obj(struct tmem_obj *obj) * always flushes for simplicity. */ int tmem_put(struct tmem_pool *pool, struct tmem_oid *oidp, uint32_t index, - struct page *page) + char *data, size_t size, bool raw, bool ephemeral) { struct tmem_obj *obj = NULL, *objfound = NULL, *objnew = NULL; void *pampd = NULL, *pampd_del = NULL; int ret = -ENOMEM; - bool ephemeral; struct tmem_hashbucket *hb; - ephemeral = is_ephemeral(pool); hb = &pool->hashbucket[tmem_oid_hash(oidp)]; spin_lock(&hb->lock); obj = objfound = tmem_obj_find(hb, oidp); @@ -521,7 +545,7 @@ int tmem_put(struct tmem_pool *pool, struct tmem_oid *oidp, uint32_t index, /* if found, is a dup put, flush the old one */ pampd_del = tmem_pampd_delete_from_obj(obj, index); BUG_ON(pampd_del != pampd); - (*tmem_pamops.free)(pampd, pool); + (*tmem_pamops.free)(pampd, pool, oidp, index); if (obj->pampd_count == 0) { objnew = obj; objfound = NULL; @@ -538,7 +562,8 @@ int tmem_put(struct tmem_pool *pool, struct tmem_oid *oidp, uint32_t index, } BUG_ON(obj == NULL); BUG_ON(((objnew != obj) && (objfound != obj)) || (objnew == objfound)); - pampd = (*tmem_pamops.create)(obj->pool, &obj->oid, index, page); + pampd = (*tmem_pamops.create)(data, size, raw, ephemeral, + obj->pool, &obj->oid, index); if (unlikely(pampd == NULL)) goto free; ret = tmem_pampd_add_to_obj(obj, index, pampd); @@ -551,7 +576,7 @@ delete_and_free: (void)tmem_pampd_delete_from_obj(obj, index); free: if (pampd) - (*tmem_pamops.free)(pampd, pool); + (*tmem_pamops.free)(pampd, pool, NULL, 0); if (objnew) { tmem_obj_free(objnew, hb); (*tmem_hostops.obj_free)(objnew, pool); @@ -573,41 +598,52 @@ out: * "put" done with the same handle). */ -int tmem_get(struct tmem_pool *pool, struct tmem_oid *oidp, - uint32_t index, struct page *page) +int tmem_get(struct tmem_pool *pool, struct tmem_oid *oidp, uint32_t index, + char *data, size_t *size, bool raw, int get_and_free) { struct tmem_obj *obj; void *pampd; bool ephemeral = is_ephemeral(pool); uint32_t ret = -1; struct tmem_hashbucket *hb; + bool free = (get_and_free == 1) || ((get_and_free == 0) && ephemeral); + bool lock_held = false; hb = &pool->hashbucket[tmem_oid_hash(oidp)]; spin_lock(&hb->lock); + lock_held = true; obj = tmem_obj_find(hb, oidp); if (obj == NULL) goto out; - ephemeral = is_ephemeral(pool); - if (ephemeral) + if (free) pampd = tmem_pampd_delete_from_obj(obj, index); else pampd = tmem_pampd_lookup_in_obj(obj, index); if (pampd == NULL) goto out; - ret = (*tmem_pamops.get_data)(page, pampd, pool); - if (ret < 0) - goto out; - if (ephemeral) { - (*tmem_pamops.free)(pampd, pool); + if (free) { if (obj->pampd_count == 0) { tmem_obj_free(obj, hb); (*tmem_hostops.obj_free)(obj, pool); obj = NULL; } } + if (tmem_pamops.is_remote(pampd)) { + lock_held = false; + spin_unlock(&hb->lock); + } + if (free) + ret = (*tmem_pamops.get_data_and_free)( + data, size, raw, pampd, pool, oidp, index); + else + ret = (*tmem_pamops.get_data)( + data, size, raw, pampd, pool, oidp, index); + if (ret < 0) + goto out; ret = 0; out: - spin_unlock(&hb->lock); + if (lock_held) + spin_unlock(&hb->lock); return ret; } @@ -632,7 +668,7 @@ int tmem_flush_page(struct tmem_pool *pool, pampd = tmem_pampd_delete_from_obj(obj, index); if (pampd == NULL) goto out; - (*tmem_pamops.free)(pampd, pool); + (*tmem_pamops.free)(pampd, pool, oidp, index); if (obj->pampd_count == 0) { tmem_obj_free(obj, hb); (*tmem_hostops.obj_free)(obj, pool); @@ -644,6 +680,30 @@ out: return ret; } +/* + * If a page in tmem matches the handle, replace the page so that any + * subsequent "get" gets the new page. Returns 0 if + * there was a page to replace, else returns -1. + */ +int tmem_replace(struct tmem_pool *pool, struct tmem_oid *oidp, + uint32_t index, void *new_pampd) +{ + struct tmem_obj *obj; + int ret = -1; + struct tmem_hashbucket *hb; + + hb = &pool->hashbucket[tmem_oid_hash(oidp)]; + spin_lock(&hb->lock); + obj = tmem_obj_find(hb, oidp); + if (obj == NULL) + goto out; + new_pampd = tmem_pampd_replace_in_obj(obj, index, new_pampd); + ret = (*tmem_pamops.replace_in_obj)(new_pampd, obj); +out: + spin_unlock(&hb->lock); + return ret; +} + /* * "Flush" all pages in tmem matching this oid. */ diff --git a/drivers/staging/zcache/tmem.h b/drivers/staging/zcache/tmem.h index 2e07e217d51f..ed147c4b110d 100644 --- a/drivers/staging/zcache/tmem.h +++ b/drivers/staging/zcache/tmem.h @@ -147,6 +147,7 @@ struct tmem_obj { unsigned int objnode_tree_height; unsigned long objnode_count; long pampd_count; + void *extra; /* for private use by pampd implementation */ DECL_SENTINEL }; @@ -166,10 +167,18 @@ struct tmem_objnode { /* pampd abstract datatype methods provided by the PAM implementation */ struct tmem_pamops { - void *(*create)(struct tmem_pool *, struct tmem_oid *, uint32_t, - struct page *); - int (*get_data)(struct page *, void *, struct tmem_pool *); - void (*free)(void *, struct tmem_pool *); + void *(*create)(char *, size_t, bool, int, + struct tmem_pool *, struct tmem_oid *, uint32_t); + int (*get_data)(char *, size_t *, bool, void *, struct tmem_pool *, + struct tmem_oid *, uint32_t); + int (*get_data_and_free)(char *, size_t *, bool, void *, + struct tmem_pool *, struct tmem_oid *, + uint32_t); + void (*free)(void *, struct tmem_pool *, struct tmem_oid *, uint32_t); + void (*free_obj)(struct tmem_pool *, struct tmem_obj *); + bool (*is_remote)(void *); + void (*new_obj)(struct tmem_obj *); + int (*replace_in_obj)(void *, struct tmem_obj *); }; extern void tmem_register_pamops(struct tmem_pamops *m); @@ -184,9 +193,11 @@ extern void tmem_register_hostops(struct tmem_hostops *m); /* core tmem accessor functions */ extern int tmem_put(struct tmem_pool *, struct tmem_oid *, uint32_t index, - struct page *page); + char *, size_t, bool, bool); extern int tmem_get(struct tmem_pool *, struct tmem_oid *, uint32_t index, - struct page *page); + char *, size_t *, bool, int); +extern int tmem_replace(struct tmem_pool *, struct tmem_oid *, uint32_t index, + void *); extern int tmem_flush_page(struct tmem_pool *, struct tmem_oid *, uint32_t index); extern int tmem_flush_object(struct tmem_pool *, struct tmem_oid *); diff --git a/drivers/staging/zcache/zcache.c b/drivers/staging/zcache/zcache.c index 77ac2d4d3ef1..65a81a0d7c49 100644 --- a/drivers/staging/zcache/zcache.c +++ b/drivers/staging/zcache/zcache.c @@ -49,6 +49,33 @@ (__GFP_FS | __GFP_NORETRY | __GFP_NOWARN | __GFP_NOMEMALLOC) #endif +#define MAX_POOLS_PER_CLIENT 16 + +#define MAX_CLIENTS 16 +#define LOCAL_CLIENT ((uint16_t)-1) +struct zcache_client { + struct tmem_pool *tmem_pools[MAX_POOLS_PER_CLIENT]; + struct xv_pool *xvpool; + bool allocated; + atomic_t refcount; +}; + +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" @@ -72,7 +99,8 @@ #define ZBUD_MAX_BUDS 2 struct zbud_hdr { - uint32_t pool_id; + 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 */ @@ -120,6 +148,7 @@ 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); @@ -294,7 +323,8 @@ static void zbud_free_and_delist(struct zbud_hdr *zh) } } -static struct zbud_hdr *zbud_create(uint32_t pool_id, struct tmem_oid *oid, +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) { @@ -353,6 +383,7 @@ init_zh: 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); @@ -407,7 +438,8 @@ static unsigned long zcache_evicted_raw_pages; static unsigned long zcache_evicted_buddied_pages; static unsigned long zcache_evicted_unbuddied_pages; -static struct tmem_pool *zcache_get_pool_by_id(uint32_t poolid); +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); /* @@ -417,7 +449,8 @@ static void zbud_evict_zbpg(struct zbud_page *zbpg) { struct zbud_hdr *zh; int i, j; - uint32_t pool_id[ZBUD_MAX_BUDS], index[ZBUD_MAX_BUDS]; + uint32_t pool_id[ZBUD_MAX_BUDS], client_id[ZBUD_MAX_BUDS]; + uint32_t index[ZBUD_MAX_BUDS]; struct tmem_oid oid[ZBUD_MAX_BUDS]; struct tmem_pool *pool; @@ -426,6 +459,7 @@ static void zbud_evict_zbpg(struct zbud_page *zbpg) for (i = 0, j = 0; i < ZBUD_MAX_BUDS; i++) { zh = &zbpg->buddy[i]; if (zh->size) { + client_id[j] = zh->client_id; pool_id[j] = zh->pool_id; oid[j] = zh->oid; index[j] = zh->index; @@ -435,7 +469,7 @@ static void zbud_evict_zbpg(struct zbud_page *zbpg) } spin_unlock(&zbpg->lock); for (i = 0; i < j; i++) { - pool = zcache_get_pool_by_id(pool_id[i]); + pool = zcache_get_pool_by_id(client_id[i], pool_id[i]); if (pool != NULL) { tmem_flush_page(pool, &oid[i], index[i]); zcache_put_pool(pool); @@ -552,9 +586,8 @@ static int zbud_show_unbuddied_list_counts(char *buf) int i; char *p = buf; - for (i = 0; i < NCHUNKS - 1; i++) + for (i = 0; i < NCHUNKS; i++) p += sprintf(p, "%u ", zbud_unbuddied[i].count); - p += sprintf(p, "%d\n", zbud_unbuddied[i].count); return p - buf; } @@ -602,7 +635,23 @@ struct zv_hdr { DECL_SENTINEL }; -static const int zv_max_page_size = (PAGE_SIZE / 8) * 7; +/* rudimentary policy limits */ +/* total number of persistent pages may not exceed this percentage */ +static unsigned int zv_page_count_policy_percent = 75; +/* + * byte count defining poor compression; pages with greater zsize will be + * rejected + */ +static unsigned int zv_max_zsize = (PAGE_SIZE / 8) * 7; +/* + * byte count defining poor *mean* compression; pages with greater zsize + * will be rejected until sufficient better-compressed pages are accepted + * driving the man below this threshold + */ +static unsigned int zv_max_mean_zsize = (PAGE_SIZE / 8) * 5; + +static unsigned long zv_curr_dist_counts[NCHUNKS]; +static unsigned long zv_cumul_dist_counts[NCHUNKS]; static struct zv_hdr *zv_create(struct xv_pool *xvpool, uint32_t pool_id, struct tmem_oid *oid, uint32_t index, @@ -611,13 +660,18 @@ static struct zv_hdr *zv_create(struct xv_pool *xvpool, uint32_t pool_id, struct page *page; struct zv_hdr *zv = NULL; uint32_t offset; + int alloc_size = clen + sizeof(struct zv_hdr); + int chunks = (alloc_size + (CHUNK_SIZE - 1)) >> CHUNK_SHIFT; int ret; BUG_ON(!irqs_disabled()); - ret = xv_malloc(xvpool, clen + sizeof(struct zv_hdr), + BUG_ON(chunks >= NCHUNKS); + ret = xv_malloc(xvpool, alloc_size, &page, &offset, ZCACHE_GFP_MASK); if (unlikely(ret)) goto out; + zv_curr_dist_counts[chunks]++; + zv_cumul_dist_counts[chunks]++; zv = kmap_atomic(page, KM_USER0) + offset; zv->index = index; zv->oid = *oid; @@ -634,11 +688,14 @@ static void zv_free(struct xv_pool *xvpool, struct zv_hdr *zv) unsigned long flags; struct page *page; uint32_t offset; - uint16_t size; + uint16_t size = xv_get_object_size(zv); + int chunks = (size + (CHUNK_SIZE - 1)) >> CHUNK_SHIFT; ASSERT_SENTINEL(zv, ZVH); - size = xv_get_object_size(zv) - sizeof(*zv); - BUG_ON(size == 0 || size > zv_max_page_size); + BUG_ON(chunks >= NCHUNKS); + zv_curr_dist_counts[chunks]--; + size -= sizeof(*zv); + BUG_ON(size == 0); INVERT_SENTINEL(zv, ZVH); page = virt_to_page(zv); offset = (unsigned long)zv & ~PAGE_MASK; @@ -656,7 +713,7 @@ static void zv_decompress(struct page *page, struct zv_hdr *zv) ASSERT_SENTINEL(zv, ZVH); size = xv_get_object_size(zv) - sizeof(*zv); - BUG_ON(size == 0 || size > zv_max_page_size); + BUG_ON(size == 0); to_va = kmap_atomic(page, KM_USER0); ret = lzo1x_decompress_safe((char *)zv + sizeof(*zv), size, to_va, &clen); @@ -665,6 +722,159 @@ static void zv_decompress(struct page *page, struct zv_hdr *zv) BUG_ON(clen != PAGE_SIZE); } +#ifdef CONFIG_SYSFS +/* + * show a distribution of compression stats for zv pages. + */ + +static int zv_curr_dist_counts_show(char *buf) +{ + unsigned long i, n, chunks = 0, sum_total_chunks = 0; + char *p = buf; + + for (i = 0; i < NCHUNKS; i++) { + n = zv_curr_dist_counts[i]; + p += sprintf(p, "%lu ", n); + chunks += n; + sum_total_chunks += i * n; + } + p += sprintf(p, "mean:%lu\n", + chunks == 0 ? 0 : sum_total_chunks / chunks); + return p - buf; +} + +static int zv_cumul_dist_counts_show(char *buf) +{ + unsigned long i, n, chunks = 0, sum_total_chunks = 0; + char *p = buf; + + for (i = 0; i < NCHUNKS; i++) { + n = zv_cumul_dist_counts[i]; + p += sprintf(p, "%lu ", n); + chunks += n; + sum_total_chunks += i * n; + } + p += sprintf(p, "mean:%lu\n", + chunks == 0 ? 0 : sum_total_chunks / chunks); + return p - buf; +} + +/* + * setting zv_max_zsize via sysfs causes all persistent (e.g. swap) + * pages that don't compress to less than this value (including metadata + * overhead) to be rejected. We don't allow the value to get too close + * to PAGE_SIZE. + */ +static ssize_t zv_max_zsize_show(struct kobject *kobj, + struct kobj_attribute *attr, + char *buf) +{ + return sprintf(buf, "%u\n", zv_max_zsize); +} + +static ssize_t zv_max_zsize_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + unsigned long val; + int err; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + err = strict_strtoul(buf, 10, &val); + if (err || (val == 0) || (val > (PAGE_SIZE / 8) * 7)) + return -EINVAL; + zv_max_zsize = val; + return count; +} + +/* + * setting zv_max_mean_zsize via sysfs causes all persistent (e.g. swap) + * pages that don't compress to less than this value (including metadata + * overhead) to be rejected UNLESS the mean compression is also smaller + * than this value. In other words, we are load-balancing-by-zsize the + * accepted pages. Again, we don't allow the value to get too close + * to PAGE_SIZE. + */ +static ssize_t zv_max_mean_zsize_show(struct kobject *kobj, + struct kobj_attribute *attr, + char *buf) +{ + return sprintf(buf, "%u\n", zv_max_mean_zsize); +} + +static ssize_t zv_max_mean_zsize_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + unsigned long val; + int err; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + err = strict_strtoul(buf, 10, &val); + if (err || (val == 0) || (val > (PAGE_SIZE / 8) * 7)) + return -EINVAL; + zv_max_mean_zsize = val; + return count; +} + +/* + * setting zv_page_count_policy_percent via sysfs sets an upper bound of + * persistent (e.g. swap) pages that will be retained according to: + * (zv_page_count_policy_percent * totalram_pages) / 100) + * when that limit is reached, further puts will be rejected (until + * some pages have been flushed). Note that, due to compression, + * this number may exceed 100; it defaults to 75 and we set an + * arbitary limit of 150. A poor choice will almost certainly result + * in OOM's, so this value should only be changed prudently. + */ +static ssize_t zv_page_count_policy_percent_show(struct kobject *kobj, + struct kobj_attribute *attr, + char *buf) +{ + return sprintf(buf, "%u\n", zv_page_count_policy_percent); +} + +static ssize_t zv_page_count_policy_percent_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + unsigned long val; + int err; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + err = strict_strtoul(buf, 10, &val); + if (err || (val == 0) || (val > 150)) + return -EINVAL; + zv_page_count_policy_percent = val; + return count; +} + +static struct kobj_attribute zcache_zv_max_zsize_attr = { + .attr = { .name = "zv_max_zsize", .mode = 0644 }, + .show = zv_max_zsize_show, + .store = zv_max_zsize_store, +}; + +static struct kobj_attribute zcache_zv_max_mean_zsize_attr = { + .attr = { .name = "zv_max_mean_zsize", .mode = 0644 }, + .show = zv_max_mean_zsize_show, + .store = zv_max_mean_zsize_store, +}; + +static struct kobj_attribute zcache_zv_page_count_policy_percent_attr = { + .attr = { .name = "zv_page_count_policy_percent", + .mode = 0644 }, + .show = zv_page_count_policy_percent_show, + .store = zv_page_count_policy_percent_store, +}; +#endif + /* * zcache core code starts here */ @@ -677,36 +887,70 @@ static unsigned long zcache_flobj_found; static unsigned long zcache_failed_eph_puts; static unsigned long zcache_failed_pers_puts; -#define MAX_POOLS_PER_CLIENT 16 - -static struct { - struct tmem_pool *tmem_pools[MAX_POOLS_PER_CLIENT]; - struct xv_pool *xvpool; -} zcache_client; - /* * Tmem operations assume the poolid implies the invoking client. - * Zcache only has one client (the kernel itself), so translate - * the poolid into the tmem_pool allocated for it. A KVM version + * 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(uint32_t poolid) +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 (poolid >= 0) { - pool = zcache_client.tmem_pools[poolid]; + 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) { - if (pool != NULL) - atomic_dec(&pool->refcount); + 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; +#ifdef CONFIG_FRONTSWAP + cli->xvpool = xv_create_pool(); + if (cli->xvpool == NULL) + goto out; +#endif + ret = 0; +out: + return ret; } /* counters for debugging */ @@ -901,48 +1145,59 @@ static unsigned long zcache_curr_pers_pampd_count_max; /* forward reference */ static int zcache_compress(struct page *from, void **out_va, size_t *out_len); -static void *zcache_pampd_create(struct tmem_pool *pool, struct tmem_oid *oid, - uint32_t index, struct page *page) +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; - bool ephemeral = is_ephemeral(pool); unsigned long count; + struct page *page = virt_to_page(data); + struct zcache_client *cli = pool->client; + uint16_t client_id = get_client_id_from_client(cli); + unsigned long zv_mean_zsize; + unsigned long curr_pers_pampd_count; - if (ephemeral) { + if (eph) { 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(pool->pool_id, oid, index, - page, cdata, clen); + 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; } } else { - /* - * FIXME: This is all the "policy" there is for now. - * 3/4 totpages should allow ~37% of RAM to be filled with - * compressed frontswap pages - */ - if (atomic_read(&zcache_curr_pers_pampd_count) > - 3 * totalram_pages / 4) + curr_pers_pampd_count = + atomic_read(&zcache_curr_pers_pampd_count); + if (curr_pers_pampd_count > + (zv_page_count_policy_percent * totalram_pages) / 100) goto out; ret = zcache_compress(page, &cdata, &clen); if (ret == 0) goto out; - if (clen > zv_max_page_size) { + /* reject if compression is too poor */ + if (clen > zv_max_zsize) { zcache_compress_poor++; goto out; } - pampd = (void *)zv_create(zcache_client.xvpool, pool->pool_id, + /* reject if mean compression is too poor */ + if ((clen > zv_max_mean_zsize) && (curr_pers_pampd_count > 0)) { + zv_mean_zsize = xv_get_total_size_bytes(cli->xvpool) / + curr_pers_pampd_count; + if (zv_mean_zsize > zv_max_mean_zsize) { + zcache_mean_compress_poor++; + goto out; + } + } + pampd = (void *)zv_create(cli->xvpool, pool->pool_id, oid, index, cdata, clen); if (pampd == NULL) goto out; @@ -958,15 +1213,31 @@ out: * fill the pageframe corresponding to the struct page with the data * from the passed pampd */ -static int zcache_pampd_get_data(struct page *page, void *pampd, - struct tmem_pool *pool) +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) { int ret = 0; - if (is_ephemeral(pool)) - ret = zbud_decompress(page, pampd); - else - zv_decompress(page, pampd); + BUG_ON(is_ephemeral(pool)); + zv_decompress(virt_to_page(data), pampd); + return ret; +} + +/* + * 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; + + BUG_ON(!is_ephemeral(pool)); + zbud_decompress(virt_to_page(data), pampd); + zbud_free_and_delist((struct zbud_hdr *)pampd); + atomic_dec(&zcache_curr_eph_pampd_count); return ret; } @@ -974,23 +1245,49 @@ static int zcache_pampd_get_data(struct page *page, void *pampd, * 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) +static void zcache_pampd_free(void *pampd, struct tmem_pool *pool, + struct tmem_oid *oid, uint32_t index) { + struct zcache_client *cli = pool->client; + if (is_ephemeral(pool)) { 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); } else { - zv_free(zcache_client.xvpool, (struct zv_hdr *)pampd); + zv_free(cli->xvpool, (struct zv_hdr *)pampd); atomic_dec(&zcache_curr_pers_pampd_count); BUG_ON(atomic_read(&zcache_curr_pers_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, }; /* @@ -1122,6 +1419,7 @@ 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_ATOMIC(zbud_curr_raw_pages); ZCACHE_SYSFS_RO_ATOMIC(zbud_curr_zpages); ZCACHE_SYSFS_RO_ATOMIC(curr_obj_count); @@ -1130,6 +1428,10 @@ 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); +ZCACHE_SYSFS_RO_CUSTOM(zv_curr_dist_counts, + zv_curr_dist_counts_show); +ZCACHE_SYSFS_RO_CUSTOM(zv_cumul_dist_counts, + zv_cumul_dist_counts_show); static struct attribute *zcache_attrs[] = { &zcache_curr_obj_count_attr.attr, @@ -1143,6 +1445,7 @@ static struct attribute *zcache_attrs[] = { &zcache_failed_eph_puts_attr.attr, &zcache_failed_pers_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, @@ -1160,6 +1463,11 @@ static struct attribute *zcache_attrs[] = { &zcache_aborted_shrink_attr.attr, &zcache_zbud_unbuddied_list_counts_attr.attr, &zcache_zbud_cumul_chunk_counts_attr.attr, + &zcache_zv_curr_dist_counts_attr.attr, + &zcache_zv_cumul_dist_counts_attr.attr, + &zcache_zv_max_zsize_attr.attr, + &zcache_zv_max_mean_zsize_attr.attr, + &zcache_zv_page_count_policy_percent_attr.attr, NULL, }; @@ -1212,19 +1520,20 @@ static struct shrinker zcache_shrinker = { * zcache shims between cleancache/frontswap ops and tmem */ -static int zcache_put_page(int pool_id, struct tmem_oid *oidp, +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(pool_id); + 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, page); + ret = tmem_put(pool, oidp, index, page_address(page), + PAGE_SIZE, 0, is_ephemeral(pool)); if (ret < 0) { if (is_ephemeral(pool)) zcache_failed_eph_puts++; @@ -1244,25 +1553,28 @@ out: return ret; } -static int zcache_get_page(int pool_id, struct tmem_oid *oidp, +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(pool_id); + 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, page); + ret = tmem_get(pool, oidp, index, page_address(page), + &size, 0, is_ephemeral(pool)); zcache_put_pool(pool); } local_irq_restore(flags); return ret; } -static int zcache_flush_page(int pool_id, struct tmem_oid *oidp, uint32_t index) +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; @@ -1270,7 +1582,7 @@ static int zcache_flush_page(int pool_id, struct tmem_oid *oidp, uint32_t index) local_irq_save(flags); zcache_flush_total++; - pool = zcache_get_pool_by_id(pool_id); + 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); @@ -1282,7 +1594,8 @@ static int zcache_flush_page(int pool_id, struct tmem_oid *oidp, uint32_t index) return ret; } -static int zcache_flush_object(int pool_id, struct tmem_oid *oidp) +static int zcache_flush_object(int cli_id, int pool_id, + struct tmem_oid *oidp) { struct tmem_pool *pool; int ret = -1; @@ -1290,7 +1603,7 @@ static int zcache_flush_object(int pool_id, struct tmem_oid *oidp) local_irq_save(flags); zcache_flobj_total++; - pool = zcache_get_pool_by_id(pool_id); + 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); @@ -1302,34 +1615,52 @@ static int zcache_flush_object(int pool_id, struct tmem_oid *oidp) return ret; } -static int zcache_destroy_pool(int pool_id) +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; - pool = zcache_client.tmem_pools[pool_id]; + 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; - zcache_client.tmem_pools[pool_id] = NULL; + 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("zcache: destroyed pool id=%d\n", pool_id); + pr_info("zcache: destroyed pool id=%d, cli_id=%d\n", + pool_id, cli_id); out: return ret; } -static int zcache_new_pool(uint32_t flags) +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("zcache: pool creation failed: out of memory\n"); @@ -1337,7 +1668,7 @@ static int zcache_new_pool(uint32_t flags) } for (poolid = 0; poolid < MAX_POOLS_PER_CLIENT; poolid++) - if (zcache_client.tmem_pools[poolid] == NULL) + if (cli->tmem_pools[poolid] == NULL) break; if (poolid >= MAX_POOLS_PER_CLIENT) { pr_info("zcache: pool creation failed: max exceeded\n"); @@ -1346,14 +1677,16 @@ static int zcache_new_pool(uint32_t flags) goto out; } atomic_set(&pool->refcount, 0); - pool->client = &zcache_client; + pool->client = cli; pool->pool_id = poolid; tmem_new_pool(pool, flags); - zcache_client.tmem_pools[poolid] = pool; - pr_info("zcache: created %s tmem pool, id=%d\n", + cli->tmem_pools[poolid] = pool; + pr_info("zcache: created %s tmem pool, id=%d, client=%d\n", flags & TMEM_POOL_PERSIST ? "persistent" : "ephemeral", - poolid); + poolid, cli_id); out: + if (cli != NULL) + atomic_dec(&cli->refcount); return poolid; } @@ -1374,7 +1707,7 @@ static void zcache_cleancache_put_page(int pool_id, struct tmem_oid oid = *(struct tmem_oid *)&key; if (likely(ind == index)) - (void)zcache_put_page(pool_id, &oid, index, page); + (void)zcache_put_page(LOCAL_CLIENT, pool_id, &oid, index, page); } static int zcache_cleancache_get_page(int pool_id, @@ -1386,7 +1719,7 @@ static int zcache_cleancache_get_page(int pool_id, int ret = -1; if (likely(ind == index)) - ret = zcache_get_page(pool_id, &oid, index, page); + ret = zcache_get_page(LOCAL_CLIENT, pool_id, &oid, index, page); return ret; } @@ -1398,7 +1731,7 @@ static void zcache_cleancache_flush_page(int pool_id, struct tmem_oid oid = *(struct tmem_oid *)&key; if (likely(ind == index)) - (void)zcache_flush_page(pool_id, &oid, ind); + (void)zcache_flush_page(LOCAL_CLIENT, pool_id, &oid, ind); } static void zcache_cleancache_flush_inode(int pool_id, @@ -1406,13 +1739,13 @@ static void zcache_cleancache_flush_inode(int pool_id, { struct tmem_oid oid = *(struct tmem_oid *)&key; - (void)zcache_flush_object(pool_id, &oid); + (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(pool_id); + (void)zcache_destroy_pool(LOCAL_CLIENT, pool_id); } static int zcache_cleancache_init_fs(size_t pagesize) @@ -1420,7 +1753,7 @@ 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(0); + return zcache_new_pool(LOCAL_CLIENT, 0); } static int zcache_cleancache_init_shared_fs(char *uuid, size_t pagesize) @@ -1429,7 +1762,7 @@ static int zcache_cleancache_init_shared_fs(char *uuid, size_t pagesize) BUG_ON(sizeof(struct cleancache_filekey) != sizeof(struct tmem_oid)); BUG_ON(pagesize != PAGE_SIZE); - return zcache_new_pool(0); + return zcache_new_pool(LOCAL_CLIENT, 0); } static struct cleancache_ops zcache_cleancache_ops = { @@ -1483,8 +1816,8 @@ static int zcache_frontswap_put_page(unsigned type, pgoff_t offset, BUG_ON(!PageLocked(page)); if (likely(ind64 == ind)) { local_irq_save(flags); - ret = zcache_put_page(zcache_frontswap_poolid, &oid, - iswiz(ind), page); + ret = zcache_put_page(LOCAL_CLIENT, zcache_frontswap_poolid, + &oid, iswiz(ind), page); local_irq_restore(flags); } return ret; @@ -1502,8 +1835,8 @@ static int zcache_frontswap_get_page(unsigned type, pgoff_t offset, BUG_ON(!PageLocked(page)); if (likely(ind64 == ind)) - ret = zcache_get_page(zcache_frontswap_poolid, &oid, - iswiz(ind), page); + ret = zcache_get_page(LOCAL_CLIENT, zcache_frontswap_poolid, + &oid, iswiz(ind), page); return ret; } @@ -1515,8 +1848,8 @@ static void zcache_frontswap_flush_page(unsigned type, pgoff_t offset) struct tmem_oid oid = oswiz(type, ind); if (likely(ind64 == ind)) - (void)zcache_flush_page(zcache_frontswap_poolid, &oid, - iswiz(ind)); + (void)zcache_flush_page(LOCAL_CLIENT, zcache_frontswap_poolid, + &oid, iswiz(ind)); } /* flush all pages from the passed swaptype */ @@ -1527,7 +1860,8 @@ static void zcache_frontswap_flush_area(unsigned type) for (ind = SWIZ_MASK; ind >= 0; ind--) { oid = oswiz(type, ind); - (void)zcache_flush_object(zcache_frontswap_poolid, &oid); + (void)zcache_flush_object(LOCAL_CLIENT, + zcache_frontswap_poolid, &oid); } } @@ -1535,7 +1869,8 @@ static void zcache_frontswap_init(unsigned ignored) { /* a single tmem poolid is used for all frontswap "types" (swapfiles) */ if (zcache_frontswap_poolid < 0) - zcache_frontswap_poolid = zcache_new_pool(TMEM_POOL_PERSIST); + zcache_frontswap_poolid = + zcache_new_pool(LOCAL_CLIENT, TMEM_POOL_PERSIST); } static struct frontswap_ops zcache_frontswap_ops = { @@ -1624,6 +1959,11 @@ static int __init zcache_init(void) 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("zcache: can't create client\n"); + goto out; + } #endif #ifdef CONFIG_CLEANCACHE if (zcache_enabled && use_cleancache) { @@ -1642,11 +1982,6 @@ static int __init zcache_init(void) if (zcache_enabled && use_frontswap) { struct frontswap_ops old_ops; - zcache_client.xvpool = xv_create_pool(); - if (zcache_client.xvpool == NULL) { - pr_err("zcache: can't create xvpool\n"); - goto out; - } old_ops = zcache_frontswap_register_ops(); pr_info("zcache: frontswap enabled using kernel " "transcendent memory and xvmalloc\n");