From: levin li <[email protected]> We put all the cached object into a global lru list, when the object cache is referenced(read/write), we move the object to the head of the lru list, then when cache reaches the max size we can reclaim it from the end of the lru list.
Signed-off-by: levin li <[email protected]> --- sheep/object_cache.c | 118 +++++++++++++++++++++++++++----------------------- 1 files changed, 64 insertions(+), 54 deletions(-) diff --git a/sheep/object_cache.c b/sheep/object_cache.c index 095546e..0ef94be 100644 --- a/sheep/object_cache.c +++ b/sheep/object_cache.c @@ -144,10 +144,31 @@ object_cache_insert(struct rb_root *root, struct object_cache_entry *new) return NULL; /* insert successfully */ } +static struct object_cache_entry *object_tree_search(struct rb_root *root, + uint32_t idx) +{ + struct rb_node *n = root->rb_node; + struct object_cache_entry *t; + + while (n) { + t = rb_entry(n, struct object_cache_entry, node); + + if (idx < t->idx) + n = n->rb_left; + else if (idx > t->idx) + n = n->rb_right; + else + return t; /* found it */ + } + + return NULL; +} + static struct object_cache_entry * -dirty_tree_insert(struct rb_root *root, struct object_cache_entry *new) +dirty_tree_insert(struct object_cache *oc, uint32_t idx, + uint64_t bmap, int create) { - struct rb_node **p = &root->rb_node; + struct rb_node **p = &oc->dirty_tree.rb_node; struct rb_node *parent = NULL; struct object_cache_entry *entry; @@ -155,20 +176,28 @@ dirty_tree_insert(struct rb_root *root, struct object_cache_entry *new) parent = *p; entry = rb_entry(parent, struct object_cache_entry, dirty_node); - if (new->idx < entry->idx) + if (idx < entry->idx) p = &(*p)->rb_left; - else if (new->idx > entry->idx) + else if (idx > entry->idx) p = &(*p)->rb_right; else { /* already has this entry, merge bmap */ - entry->bmap |= new->bmap; + entry->bmap |= bmap; return entry; } } - rb_link_node(&new->dirty_node, parent, p); - rb_insert_color(&new->dirty_node, root); - return NULL; /* insert successfully */ + entry = object_tree_search(&oc->object_tree, idx); + if (!entry) + return NULL; + + entry->bmap |= bmap; + entry->flags |= ENTRY_CREATE_BIT; + rb_link_node(&entry->dirty_node, parent, p); + rb_insert_color(&entry->dirty_node, &oc->dirty_tree); + list_add(&entry->list, &oc->dirty_list); + + return entry; } static struct object_cache_entry *dirty_tree_search(struct rb_root *root, @@ -191,26 +220,6 @@ static struct object_cache_entry *dirty_tree_search(struct rb_root *root, return NULL; } -static struct object_cache_entry *object_tree_search(struct rb_root *root, - uint32_t idx) -{ - struct rb_node *n = root->rb_node; - struct object_cache_entry *t; - - while (n) { - t = rb_entry(n, struct object_cache_entry, node); - - if (idx < t->idx) - n = n->rb_left; - else if (idx > t->idx) - n = n->rb_right; - else - return t; /* found it */ - } - - return NULL; -} - static int create_dir_for(uint32_t vid) { int ret = 0; @@ -272,36 +281,28 @@ del_from_dirty_tree_and_list(struct object_cache_entry *entry, /* Caller should hold the oc->lock */ static inline void -add_to_dirty_tree_and_list(struct object_cache *oc, - struct object_cache_entry *entry) +add_to_dirty_tree_and_list(struct object_cache *oc, uint32_t idx, + uint64_t bmap, int create) { - if (!dirty_tree_insert(&oc->dirty_tree, entry)) - list_add(&entry->list, &oc->dirty_list); - else - free(entry); -} - -static inline struct object_cache_entry * -alloc_cache_entry(uint32_t idx, uint64_t bmap, int create) -{ - struct object_cache_entry *entry = xzalloc(sizeof(*entry)); - - entry->idx = idx; - entry->bmap = bmap; - entry->flags |= ENTRY_CREATE_BIT; + struct object_cache_entry *entry; + entry = dirty_tree_insert(oc, idx, bmap, create); + if (!entry) + panic("Can not find object entry %" PRIx32 "\n", idx); - return entry; + /* If cache isn't in reclaiming, move it + * to the head of lru list */ + cds_list_del_rcu(&entry->lru_list); + cds_list_add_rcu(&entry->lru_list, + &sys_cache.cache_lru_list); } static void update_cache_entry(struct object_cache *oc, uint32_t idx, size_t datalen, off_t offset) { - struct object_cache_entry *entry; - - entry = alloc_cache_entry(idx, calc_object_bmap(datalen, offset), 0); + uint64_t bmap = calc_object_bmap(datalen, offset); pthread_rwlock_wrlock(&oc->lock); - add_to_dirty_tree_and_list(oc, entry); + add_to_dirty_tree_and_list(oc, idx, bmap, 0); pthread_rwlock_unlock(&oc->lock); } @@ -352,7 +353,6 @@ static int object_cache_lookup(struct object_cache *oc, uint32_t idx, } if (create) { - struct object_cache_entry *entry; unsigned data_length; if (idx_has_vdi_bit(idx)) @@ -368,9 +368,8 @@ static int object_cache_lookup(struct object_cache *oc, uint32_t idx, add_to_object_cache(oc, idx); - entry = alloc_cache_entry(idx, bmap, 1); pthread_rwlock_wrlock(&oc->lock); - add_to_dirty_tree_and_list(oc, entry); + add_to_dirty_tree_and_list(oc, idx, bmap, 1); pthread_rwlock_unlock(&oc->lock); } } @@ -797,6 +796,7 @@ int object_cache_handle_request(struct request *req) uint32_t vid = oid_to_vid(oid); uint32_t idx = object_cache_oid_to_idx(oid); struct object_cache *cache; + struct object_cache_entry *entry; int ret, create = 0; dprintf("%08"PRIx32", len %"PRIu32", off %"PRIu64"\n", idx, @@ -813,19 +813,29 @@ int object_cache_handle_request(struct request *req) return ret; } + pthread_rwlock_rdlock(&cache->lock); + entry = object_tree_search(&cache->object_tree, idx); + pthread_rwlock_unlock(&cache->lock); + if (hdr->flags & SD_FLAG_CMD_WRITE) { ret = write_cache_object(cache->vid, idx, req->data, hdr->data_length, hdr->obj.offset); if (ret != SD_RES_SUCCESS) goto out; update_cache_entry(cache, idx, hdr->data_length, - hdr->obj.offset); + hdr->obj.offset); } else { ret = read_cache_object(cache->vid, idx, req->data, hdr->data_length, hdr->obj.offset); if (ret != SD_RES_SUCCESS) goto out; req->rp.data_length = hdr->data_length; + + if (entry) { + cds_list_del_rcu(&entry->lru_list); + cds_list_add_rcu(&entry->lru_list, + &sys_cache.cache_lru_list); + } } out: return ret; -- 1.7.1 -- sheepdog mailing list [email protected] http://lists.wpkg.org/mailman/listinfo/sheepdog
