Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753455Ab3F2CzY (ORCPT ); Fri, 28 Jun 2013 22:55:24 -0400 Received: from ipmail04.adl6.internode.on.net ([150.101.137.141]:63349 "EHLO ipmail04.adl6.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752817Ab3F2CzX (ORCPT ); Fri, 28 Jun 2013 22:55:23 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AnwMAE1KzlF5LB/8/2dsb2JhbABbgwmDGbdMhR8EAYEKF3SCIwEBBTocIxAIAw4KCSUPBSUDIROIDrpZFo18J4EdB4NnA5dEih+HJ4MjKoEs Date: Sat, 29 Jun 2013 12:55:09 +1000 From: Dave Chinner To: Michal Hocko Cc: Glauber Costa , Andrew Morton , linux-mm@kvack.org, LKML Subject: Re: linux-next: slab shrinkers: BUG at mm/list_lru.c:92 Message-ID: <20130629025509.GG9047@dastard> References: <20130617223004.GB2538@localhost.localdomain> <20130618024623.GP29338@dastard> <20130618063104.GB20528@localhost.localdomain> <20130618082414.GC13677@dhcp22.suse.cz> <20130618104443.GH13677@dhcp22.suse.cz> <20130618135025.GK13677@dhcp22.suse.cz> <20130625022754.GP29376@dastard> <20130626081509.GF28748@dhcp22.suse.cz> <20130626232426.GA29034@dastard> <20130627145411.GA24206@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130627145411.GA24206@dhcp22.suse.cz> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3714 Lines: 79 On Thu, Jun 27, 2013 at 04:54:11PM +0200, Michal Hocko wrote: > On Thu 27-06-13 09:24:26, Dave Chinner wrote: > > On Wed, Jun 26, 2013 at 10:15:09AM +0200, Michal Hocko wrote: > > > On Tue 25-06-13 12:27:54, Dave Chinner wrote: > > > > On Tue, Jun 18, 2013 at 03:50:25PM +0200, Michal Hocko wrote: > > > > > And again, another hang. It looks like the inode deletion never > > > > > finishes. The good thing is that I do not see any LRU related BUG_ONs > > > > > anymore. I am going to test with the other patch in the thread. > > > > > > > > > > 2476 [] __wait_on_freeing_inode+0x9e/0xc0 <<< waiting for an inode to go away > > > > > [] find_inode_fast+0xa1/0xc0 > > > > > [] iget_locked+0x4f/0x180 > > > > > [] ext4_iget+0x33/0x9f0 > > > > > [] ext4_lookup+0xbc/0x160 > > > > > [] lookup_real+0x20/0x60 > > > > > [] lookup_open+0x175/0x1d0 > > > > > [] do_last+0x2de/0x780 <<< holds i_mutex > > > > > [] path_openat+0xda/0x400 > > > > > [] do_filp_open+0x43/0xa0 > > > > > [] do_sys_open+0x160/0x1e0 > > > > > [] sys_open+0x1c/0x20 > > > > > [] system_call_fastpath+0x16/0x1b > > > > > [] 0xffffffffffffffff > > > > > > > > I don't think this has anything to do with LRUs. > > > > > > I am not claiming that. It might be a timing issue which never mattered > > > but it is strange I can reproduce this so easily and repeatedly with the > > > shrinkers patchset applied. > > > As I said earlier, this might be breakage in my -mm tree as well > > > (missing some patch which didn't go via Andrew or misapplied patch). The > > > situation is worsen by the state of linux-next which has some unrelated > > > issues. > > > > > > I really do not want to delay the whole patchset just because of some > > > problem on my side. Do you have any tree that I should try to test? > > > > No, I've just been testing Glauber's tree and sending patches for > > problems back to him based on it. > > > > > > I won't have seen this on XFS stress testing, because it doesn't use > > > > the VFS inode hashes for inode lookups. Given that XFS is not > > > > triggering either problem you are seeing, that makes me think > > > > > > I haven't tested with xfs. > > > > That might be worthwhile if you can easily do that - another data > > point indicating a hang or absence of a hang will help point us in > > the right direction here... > > OK, still hanging (with inode_lru_isolate-fix.patch). It is not the same > thing, though, as xfs seem to do lookup slightly differently. > 12467 [] xfs_iget+0xbe/0x190 [xfs] > [] xfs_lookup+0xe8/0x110 [xfs] > [] xfs_vn_lookup+0x49/0x90 [xfs] > [] lookup_real+0x20/0x60 > [] lookup_open+0x175/0x1d0 > [] do_last+0x2de/0x780 > [] path_openat+0xda/0x400 > [] do_filp_open+0x43/0xa0 > [] do_sys_open+0x160/0x1e0 > [] sys_open+0x1c/0x20 > [] system_call_fastpath+0x16/0x1b > [] 0xffffffffffffffff What are the full traces? This could be blocking on IO or locks here if it's a cache miss and we are reading an inode.... Cheers, Dave. -- Dave Chinner david@fromorbit.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/