From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754024Ab3DMXDL (ORCPT ); Sat, 13 Apr 2013 19:03:11 -0400 Received: from mail-pa0-f50.google.com ([209.85.220.50]:48104 "EHLO mail-pa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752955Ab3DMXDJ (ORCPT ); Sat, 13 Apr 2013 19:03:09 -0400 Date: Sat, 13 Apr 2013 16:03:06 -0700 (PDT) From: Hugh Dickins X-X-Sender: hugh@eggly.anvils To: Al Viro cc: Christoph Hellwig , Linus Torvalds , Andrew Morton , Suleiman Souhlal , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] vfs: Revert spurious fix to spinning prevention in prune_icache_sb Message-ID: User-Agent: Alpine 2.00 (LNX 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Suleiman Souhlal Revert v3.2's 62a3dde ("vfs: fix spinning prevention in prune_icache_sb"). This commit doesn't look right: Since we are looking at the tail of the list (sb->s_inode_lru.prev) if we want to skip an inode, we should put it back at the head of the list instead of the tail, otherwise we will keep spinning on it. Discovered when investigating why prune_icache_sb came top in perf reports of a swapping load. Signed-off-by: Suleiman Souhlal Signed-off-by: Hugh Dickins Cc: stable@vger.kernel.org --- fs/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/inode.c +++ b/fs/inode.c @@ -725,7 +725,7 @@ void prune_icache_sb(struct super_block *sb, int nr_to_scan, int priority) * inode to the back of the list so we don't spin on it. */ if (!spin_trylock(&inode->i_lock)) { - list_move_tail(&inode->i_lru, &sb->s_inode_lru); + list_move(&inode->i_lru, &sb->s_inode_lru); continue; }