linux/fs/bcachefs/btree_key_cache.h
Kent Overstreet 331194a230 bcachefs: btree key cache locking improvements
The btree key cache mutex was becoming a significant bottleneck - it was
mainly used to protect the lists of dirty, clean and freed cached keys.

This patch eliminates the dirty and clean lists - instead, when we need
to scan for keys to drop from the cache we iterate over the rhashtable,
and thus we're able to remove most uses of that lock.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:57 -04:00

51 lines
1.7 KiB
C

#ifndef _BCACHEFS_BTREE_KEY_CACHE_H
#define _BCACHEFS_BTREE_KEY_CACHE_H
static inline size_t bch2_nr_btree_keys_need_flush(struct bch_fs *c)
{
size_t nr_dirty = atomic_long_read(&c->btree_key_cache.nr_dirty);
size_t nr_keys = atomic_long_read(&c->btree_key_cache.nr_keys);
size_t max_dirty = 1024 + nr_keys / 2;
return max_t(ssize_t, 0, nr_dirty - max_dirty);
}
static inline bool bch2_btree_key_cache_must_wait(struct bch_fs *c)
{
size_t nr_dirty = atomic_long_read(&c->btree_key_cache.nr_dirty);
size_t nr_keys = atomic_long_read(&c->btree_key_cache.nr_keys);
size_t max_dirty = 4096 + (nr_keys * 3) / 4;
return nr_dirty > max_dirty &&
test_bit(JOURNAL_RECLAIM_STARTED, &c->journal.flags);
}
struct bkey_cached *
bch2_btree_key_cache_find(struct bch_fs *, enum btree_id, struct bpos);
int bch2_btree_iter_traverse_cached(struct btree_iter *);
bool bch2_btree_insert_key_cached(struct btree_trans *,
struct btree_iter *, struct bkey_i *);
int bch2_btree_key_cache_flush(struct btree_trans *,
enum btree_id, struct bpos);
#ifdef CONFIG_BCACHEFS_DEBUG
void bch2_btree_key_cache_verify_clean(struct btree_trans *,
enum btree_id, struct bpos);
#else
static inline void
bch2_btree_key_cache_verify_clean(struct btree_trans *trans,
enum btree_id id, struct bpos pos) {}
#endif
void bch2_fs_btree_key_cache_exit(struct btree_key_cache *);
void bch2_fs_btree_key_cache_init_early(struct btree_key_cache *);
int bch2_fs_btree_key_cache_init(struct btree_key_cache *);
void bch2_btree_key_cache_to_text(struct printbuf *, struct btree_key_cache *);
void bch2_btree_key_cache_exit(void);
int __init bch2_btree_key_cache_init(void);
#endif /* _BCACHEFS_BTREE_KEY_CACHE_H */