Commit 7989a502 authored by Coly Li's avatar Coly Li Committed by Greg Kroah-Hartman

bcache: only clear BTREE_NODE_dirty bit when it is set

[ Upstream commit e5ec5f47 ]

In bch_btree_cache_free() and btree_node_free(), BTREE_NODE_dirty is
always set no matter btree node is dirty or not. The code looks like
this,
	if (btree_node_dirty(b))
		btree_complete_write(b, btree_current_write(b));
	clear_bit(BTREE_NODE_dirty, &b->flags);

Indeed if btree_node_dirty(b) returns false, it means BTREE_NODE_dirty
bit is cleared, then it is unnecessary to clear the bit again.

This patch only clears BTREE_NODE_dirty when btree_node_dirty(b) is
true (the bit is set), to save a few CPU cycles.
Signed-off-by: default avatarColy Li <colyli@suse.de>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 652993a5
...@@ -772,10 +772,10 @@ void bch_btree_cache_free(struct cache_set *c) ...@@ -772,10 +772,10 @@ void bch_btree_cache_free(struct cache_set *c)
while (!list_empty(&c->btree_cache)) { while (!list_empty(&c->btree_cache)) {
b = list_first_entry(&c->btree_cache, struct btree, list); b = list_first_entry(&c->btree_cache, struct btree, list);
if (btree_node_dirty(b)) if (btree_node_dirty(b)) {
btree_complete_write(b, btree_current_write(b)); btree_complete_write(b, btree_current_write(b));
clear_bit(BTREE_NODE_dirty, &b->flags); clear_bit(BTREE_NODE_dirty, &b->flags);
}
mca_data_free(b); mca_data_free(b);
} }
...@@ -1063,9 +1063,10 @@ static void btree_node_free(struct btree *b) ...@@ -1063,9 +1063,10 @@ static void btree_node_free(struct btree *b)
mutex_lock(&b->write_lock); mutex_lock(&b->write_lock);
if (btree_node_dirty(b)) if (btree_node_dirty(b)) {
btree_complete_write(b, btree_current_write(b)); btree_complete_write(b, btree_current_write(b));
clear_bit(BTREE_NODE_dirty, &b->flags); clear_bit(BTREE_NODE_dirty, &b->flags);
}
mutex_unlock(&b->write_lock); mutex_unlock(&b->write_lock);
......
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