From c043a3303c11cdf53ee98db67cee11931b626e22 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Mon, 27 Dec 2021 22:11:54 -0500 Subject: [PATCH] bcachefs: Fix bch2_btree_cache_scan() It was counting nodes on the freed list that it skips - because we want to leave a few so that btree splits don't touch the allocator - as nodes that it touched, meaning that if it was called with <= 3 nodes to reclaim, and those nodes were on the freed list, it would never do any work. Signed-off-by: Kent Overstreet Signed-off-by: Kent Overstreet --- fs/bcachefs/btree_cache.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/fs/bcachefs/btree_cache.c b/fs/bcachefs/btree_cache.c index 2152813554b48..97b4f87a377fa 100644 --- a/fs/bcachefs/btree_cache.c +++ b/fs/bcachefs/btree_cache.c @@ -281,13 +281,19 @@ static unsigned long bch2_btree_cache_scan(struct shrinker *shrink, i = 0; list_for_each_entry_safe(b, t, &bc->freeable, list) { + /* + * Leave a few nodes on the freeable list, so that a btree split + * won't have to hit the system allocator: + */ + if (++i <= 3) + continue; + touched++; if (freed >= nr) break; - if (++i > 3 && - !btree_node_reclaim(c, b)) { + if (!btree_node_reclaim(c, b)) { btree_node_data_free(c, b); six_unlock_write(&b->c.lock); six_unlock_intent(&b->c.lock); -- 2.30.2