1

bcachefs: Add hysteresis to waiting on btree key cache flush

This helps ensure key cache reclaim isn't contending with threads
waiting for the key cache to be helped, and fixes a severe performance
bug.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This commit is contained in:
Kent Overstreet 2024-08-10 14:40:09 -04:00
parent b2f11c6f3e
commit 7254555c44
2 changed files with 10 additions and 1 deletions

View File

@ -20,6 +20,15 @@ static inline bool bch2_btree_key_cache_must_wait(struct bch_fs *c)
return nr_dirty > max_dirty;
}
static inline bool bch2_btree_key_cache_wait_done(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 = 2048 + (nr_keys * 5) / 8;
return nr_dirty <= max_dirty;
}
int bch2_btree_key_cache_journal_flush(struct journal *,
struct journal_entry_pin *, u64);

View File

@ -927,7 +927,7 @@ static inline int do_bch2_trans_commit(struct btree_trans *trans, unsigned flags
static int journal_reclaim_wait_done(struct bch_fs *c)
{
int ret = bch2_journal_error(&c->journal) ?:
!bch2_btree_key_cache_must_wait(c);
bch2_btree_key_cache_wait_done(c);
if (!ret)
journal_reclaim_kick(&c->journal);