From: Jeff Mahoney Date: Tue, 27 May 2014 17:53:20 +0000 (-0400) Subject: btrfs: free delayed node outside of root->inode_lock X-Git-Tag: firefly_0821_release~176^2~3585^2~57 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=964930312aec583809a690868119ce716f4ee926;p=firefly-linux-kernel-4.4.55.git btrfs: free delayed node outside of root->inode_lock On heavy workloads, we're seeing soft lockup warnings on root->inode_lock in __btrfs_release_delayed_node. The low hanging fruit is to reduce the size of the critical section. Signed-off-by: Jeff Mahoney Reviewed-by: David Sterba Signed-off-by: Chris Mason --- diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c index 33e561a84013..da775bfdebc9 100644 --- a/fs/btrfs/delayed-inode.c +++ b/fs/btrfs/delayed-inode.c @@ -149,8 +149,8 @@ again: spin_lock(&root->inode_lock); ret = radix_tree_insert(&root->delayed_nodes_tree, ino, node); if (ret == -EEXIST) { - kmem_cache_free(delayed_node_cache, node); spin_unlock(&root->inode_lock); + kmem_cache_free(delayed_node_cache, node); radix_tree_preload_end(); goto again; } @@ -267,14 +267,17 @@ static void __btrfs_release_delayed_node( mutex_unlock(&delayed_node->mutex); if (atomic_dec_and_test(&delayed_node->refs)) { + bool free = false; struct btrfs_root *root = delayed_node->root; spin_lock(&root->inode_lock); if (atomic_read(&delayed_node->refs) == 0) { radix_tree_delete(&root->delayed_nodes_tree, delayed_node->inode_id); - kmem_cache_free(delayed_node_cache, delayed_node); + free = true; } spin_unlock(&root->inode_lock); + if (free) + kmem_cache_free(delayed_node_cache, delayed_node); } }