From: Kent Overstreet Date: Mon, 20 Dec 2021 00:02:50 +0000 (-0500) Subject: bcachefs: Optimize memory accesses in bch2_btree_node_get() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=1aeed4549de41cabf8e7f52c62646bac7b20a385;p=linux.git bcachefs: Optimize memory accesses in bch2_btree_node_get() This puts a load behind some branches before where it's used, so that it can execute in parallel with other loads. Signed-off-by: Kent Overstreet --- diff --git a/fs/bcachefs/btree_cache.c b/fs/bcachefs/btree_cache.c index 4e855ae517316..5bf493a315caf 100644 --- a/fs/bcachefs/btree_cache.c +++ b/fs/bcachefs/btree_cache.c @@ -775,16 +775,17 @@ struct btree *bch2_btree_node_get(struct btree_trans *trans, struct btree_path * EBUG_ON(level >= BTREE_MAX_DEPTH); - if (c->opts.btree_node_mem_ptr_optimization) { - b = btree_node_mem_ptr(k); - /* - * Check b->hash_val _before_ calling btree_node_lock() - this - * might not be the node we want anymore, and trying to lock the - * wrong node could cause an unneccessary transaction restart: - */ - if (b && b->hash_val == btree_ptr_hash_val(k)) + b = btree_node_mem_ptr(k); + + /* + * Check b->hash_val _before_ calling btree_node_lock() - this might not + * be the node we want anymore, and trying to lock the wrong node could + * cause an unneccessary transaction restart: + */ + if (likely(c->opts.btree_node_mem_ptr_optimization && + b && + b->hash_val == btree_ptr_hash_val(k))) goto lock_node; - } retry: b = btree_cache_find(bc, k); if (unlikely(!b)) {