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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-04 01:49:36 +00:00
bcachefs: Improve btree key cache shrinker
The shrinker should start scanning for entries that can be freed oldest to newest - this way, we can avoid scanning a lot of entries that are too new to be freed. Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This commit is contained in:
parent
4e92cbb642
commit
125907203c
2 changed files with 49 additions and 50 deletions
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@ -78,10 +78,13 @@ static void bkey_cached_free(struct btree_key_cache *bc,
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{
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struct bch_fs *c = container_of(bc, struct bch_fs, btree_key_cache);
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BUG_ON(test_bit(BKEY_CACHED_DIRTY, &ck->flags));
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ck->btree_trans_barrier_seq =
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start_poll_synchronize_srcu(&c->btree_trans_barrier);
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list_move(&ck->list, &bc->freed);
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list_move_tail(&ck->list, &bc->freed);
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bc->nr_freed++;
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kfree(ck->k);
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ck->k = NULL;
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@ -96,9 +99,21 @@ bkey_cached_alloc(struct btree_key_cache *c)
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{
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struct bkey_cached *ck;
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list_for_each_entry(ck, &c->freed, list)
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if (bkey_cached_lock_for_evict(ck))
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list_for_each_entry_reverse(ck, &c->freed, list)
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if (bkey_cached_lock_for_evict(ck)) {
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c->nr_freed--;
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return ck;
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}
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ck = kmem_cache_alloc(bch2_key_cache, GFP_NOFS|__GFP_ZERO);
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if (likely(ck)) {
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INIT_LIST_HEAD(&ck->list);
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six_lock_init(&ck->c.lock);
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lockdep_set_novalidate_class(&ck->c.lock);
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BUG_ON(!six_trylock_intent(&ck->c.lock));
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BUG_ON(!six_trylock_write(&ck->c.lock));
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return ck;
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}
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list_for_each_entry(ck, &c->clean, list)
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if (bkey_cached_lock_for_evict(ck)) {
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@ -106,17 +121,7 @@ bkey_cached_alloc(struct btree_key_cache *c)
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return ck;
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}
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ck = kmem_cache_alloc(bch2_key_cache, GFP_NOFS|__GFP_ZERO);
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if (!ck)
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return NULL;
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INIT_LIST_HEAD(&ck->list);
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six_lock_init(&ck->c.lock);
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lockdep_set_novalidate_class(&ck->c.lock);
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BUG_ON(!six_trylock_intent(&ck->c.lock));
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BUG_ON(!six_trylock_write(&ck->c.lock));
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return ck;
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return NULL;
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}
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static struct bkey_cached *
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@ -135,8 +140,7 @@ btree_key_cache_create(struct btree_key_cache *c,
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ck->key.btree_id = btree_id;
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ck->key.pos = pos;
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ck->valid = false;
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BUG_ON(ck->flags);
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ck->flags = 1U << BKEY_CACHED_ACCESSED;
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if (rhashtable_lookup_insert_fast(&c->table,
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&ck->hash,
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@ -293,6 +297,9 @@ int bch2_btree_iter_traverse_cached(struct btree_iter *iter)
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goto err;
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}
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if (!test_bit(BKEY_CACHED_ACCESSED, &ck->flags))
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set_bit(BKEY_CACHED_ACCESSED, &ck->flags);
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iter->uptodate = BTREE_ITER_NEED_PEEK;
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bch2_btree_iter_downgrade(iter);
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return ret;
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@ -512,28 +519,34 @@ static unsigned long bch2_btree_key_cache_scan(struct shrinker *shrink,
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flags = memalloc_nofs_save();
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/*
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* Newest freed entries are at the end of the list - once we hit one
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* that's too new to be freed, we can bail out:
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*/
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list_for_each_entry_safe(ck, t, &bc->freed, list) {
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if (!poll_state_synchronize_srcu(&c->btree_trans_barrier,
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ck->btree_trans_barrier_seq))
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break;
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list_del(&ck->list);
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kmem_cache_free(bch2_key_cache, ck);
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bc->nr_freed--;
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scanned++;
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if (poll_state_synchronize_srcu(&c->btree_trans_barrier,
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ck->btree_trans_barrier_seq)) {
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list_del(&ck->list);
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kmem_cache_free(bch2_key_cache, ck);
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freed++;
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}
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if (scanned >= nr)
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goto out;
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freed++;
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}
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list_for_each_entry_safe(ck, t, &bc->clean, list) {
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scanned++;
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if (scanned >= nr)
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goto out;
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if (bkey_cached_lock_for_evict(ck)) {
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list_for_each_entry_safe(ck, t, &bc->clean, list) {
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if (test_bit(BKEY_CACHED_ACCESSED, &ck->flags))
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clear_bit(BKEY_CACHED_ACCESSED, &ck->flags);
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else if (bkey_cached_lock_for_evict(ck)) {
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bkey_cached_evict(bc, ck);
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bkey_cached_free(bc, ck);
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}
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scanned++;
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if (scanned >= nr) {
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if (&t->list != &bc->clean)
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list_move_tail(&bc->clean, &t->list);
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@ -602,6 +615,7 @@ int bch2_fs_btree_key_cache_init(struct btree_key_cache *bc)
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{
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struct bch_fs *c = container_of(bc, struct bch_fs, btree_key_cache);
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bc->shrink.seeks = 1;
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bc->shrink.count_objects = bch2_btree_key_cache_count;
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bc->shrink.scan_objects = bch2_btree_key_cache_scan;
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@ -611,26 +625,9 @@ int bch2_fs_btree_key_cache_init(struct btree_key_cache *bc)
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void bch2_btree_key_cache_to_text(struct printbuf *out, struct btree_key_cache *c)
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{
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struct bucket_table *tbl;
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struct bkey_cached *ck;
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struct rhash_head *pos;
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size_t i;
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mutex_lock(&c->lock);
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tbl = rht_dereference_rcu(c->table.tbl, &c->table);
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for (i = 0; i < tbl->size; i++) {
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rht_for_each_entry_rcu(ck, pos, tbl, i, hash) {
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pr_buf(out, "%s:",
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bch2_btree_ids[ck->key.btree_id]);
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bch2_bpos_to_text(out, ck->key.pos);
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if (test_bit(BKEY_CACHED_DIRTY, &ck->flags))
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pr_buf(out, " journal seq %llu", ck->journal.seq);
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pr_buf(out, "\n");
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}
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}
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mutex_unlock(&c->lock);
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pr_buf(out, "nr_freed:\t%zu\n", c->nr_freed);
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pr_buf(out, "nr_keys:\t%zu\n", c->nr_keys);
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pr_buf(out, "nr_dirty:\t%zu\n", c->nr_dirty);
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}
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void bch2_btree_key_cache_exit(void)
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@ -298,6 +298,7 @@ struct btree_key_cache {
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struct list_head dirty;
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struct shrinker shrink;
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size_t nr_freed;
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size_t nr_keys;
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size_t nr_dirty;
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};
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@ -307,7 +308,8 @@ struct bkey_cached_key {
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struct bpos pos;
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} __attribute__((packed, aligned(4)));
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#define BKEY_CACHED_DIRTY 0
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#define BKEY_CACHED_ACCESSED 0
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#define BKEY_CACHED_DIRTY 1
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struct bkey_cached {
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struct btree_bkey_cached_common c;
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