From: Michal Hocko <mhocko@suse.cz> To: Glauber Costa <glommer@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org>, Dave Chinner <david@fromorbit.com>, linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org> Subject: Re: linux-next: slab shrinkers: BUG at mm/list_lru.c:92 Date: Wed, 26 Jun 2013 10:22:20 +0200 [thread overview] Message-ID: <20130626082220.GG28748@dhcp22.suse.cz> (raw) In-Reply-To: <20130623115127.GA7986@localhost.localdomain> On Sun 23-06-13 15:51:29, Glauber Costa wrote: > On Fri, Jun 21, 2013 at 11:00:21AM +0200, Michal Hocko wrote: > > On Thu 20-06-13 17:12:01, Michal Hocko wrote: > > > I am bisecting it again. It is quite tedious, though, because good case > > > is hard to be sure about. > > > > OK, so now I converged to 2d4fc052 (inode: convert inode lru list to generic lru > > list code.) in my tree and I have double checked it matches what is in > > the linux-next. This doesn't help much to pin point the issue I am > > afraid :/ > > > Can you revert this patch (easiest way ATM is to rewind your tree to a point > right before it) and apply the following patch? OK, I am testing it now. > As Dave has mentioned, it is very likely that this bug was already there, we > were just not ever checking imbalances. The attached patch would tell us at > least if the imbalance was there before. Maybe I wasn't clear before but I have seen mostly hangs (posted earlier) during bisection. I do not remember BUG_ONs on imbalances after inode_lru_isolate fix. > If this is the case, I would suggest > turning the BUG condition into a WARN_ON_ONCE since we would be officially > not introducing any regression. It is no less of a bug, though, and we should > keep looking for it. > > The main change from before / after the patch is that we are now keeping things > per node. One possibility of having this BUGing would be to have an inode to be > inserted into one node-lru and removed from another. I cannot see how it could > happen, because kernel pages are stable in memory and are not moved from node > to node. We could still have some sort of weird bug in the node calculation > function. > In any case, would it be possible for you to artificially restrict > your setup to a single node ? Although I have no idea how to do that, we seem > to have no parameter to disable numa. Maybe booting with less memory, enough to > fit a single node? I can play with memmap to use areas on from a single node. Let's see whether the patch in the follow up email shows something first. -- Michal Hocko SUSE Labs
WARNING: multiple messages have this Message-ID (diff)
From: Michal Hocko <mhocko@suse.cz> To: Glauber Costa <glommer@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org>, Dave Chinner <david@fromorbit.com>, linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org> Subject: Re: linux-next: slab shrinkers: BUG at mm/list_lru.c:92 Date: Wed, 26 Jun 2013 10:22:20 +0200 [thread overview] Message-ID: <20130626082220.GG28748@dhcp22.suse.cz> (raw) In-Reply-To: <20130623115127.GA7986@localhost.localdomain> On Sun 23-06-13 15:51:29, Glauber Costa wrote: > On Fri, Jun 21, 2013 at 11:00:21AM +0200, Michal Hocko wrote: > > On Thu 20-06-13 17:12:01, Michal Hocko wrote: > > > I am bisecting it again. It is quite tedious, though, because good case > > > is hard to be sure about. > > > > OK, so now I converged to 2d4fc052 (inode: convert inode lru list to generic lru > > list code.) in my tree and I have double checked it matches what is in > > the linux-next. This doesn't help much to pin point the issue I am > > afraid :/ > > > Can you revert this patch (easiest way ATM is to rewind your tree to a point > right before it) and apply the following patch? OK, I am testing it now. > As Dave has mentioned, it is very likely that this bug was already there, we > were just not ever checking imbalances. The attached patch would tell us at > least if the imbalance was there before. Maybe I wasn't clear before but I have seen mostly hangs (posted earlier) during bisection. I do not remember BUG_ONs on imbalances after inode_lru_isolate fix. > If this is the case, I would suggest > turning the BUG condition into a WARN_ON_ONCE since we would be officially > not introducing any regression. It is no less of a bug, though, and we should > keep looking for it. > > The main change from before / after the patch is that we are now keeping things > per node. One possibility of having this BUGing would be to have an inode to be > inserted into one node-lru and removed from another. I cannot see how it could > happen, because kernel pages are stable in memory and are not moved from node > to node. We could still have some sort of weird bug in the node calculation > function. > In any case, would it be possible for you to artificially restrict > your setup to a single node ? Although I have no idea how to do that, we seem > to have no parameter to disable numa. Maybe booting with less memory, enough to > fit a single node? I can play with memmap to use areas on from a single node. Let's see whether the patch in the follow up email shows something first. -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2013-06-26 8:22 UTC|newest] Thread overview: 127+ messages / expand[flat|nested] mbox.gz Atom feed top 2013-06-17 14:18 linux-next: slab shrinkers: BUG at mm/list_lru.c:92 Michal Hocko 2013-06-17 14:18 ` Michal Hocko 2013-06-17 15:14 ` Glauber Costa 2013-06-17 15:14 ` Glauber Costa 2013-06-17 15:33 ` Michal Hocko 2013-06-17 15:33 ` Michal Hocko 2013-06-17 16:54 ` Glauber Costa 2013-06-17 16:54 ` Glauber Costa 2013-06-18 7:42 ` Michal Hocko 2013-06-18 7:42 ` Michal Hocko 2013-06-17 21:35 ` Andrew Morton 2013-06-17 21:35 ` Andrew Morton 2013-06-17 22:30 ` Glauber Costa 2013-06-18 2:46 ` Dave Chinner 2013-06-18 2:46 ` Dave Chinner 2013-06-18 6:31 ` Glauber Costa 2013-06-18 6:31 ` Glauber Costa 2013-06-18 8:24 ` Michal Hocko 2013-06-18 8:24 ` Michal Hocko 2013-06-18 10:44 ` Michal Hocko 2013-06-18 10:44 ` Michal Hocko 2013-06-18 13:50 ` Michal Hocko 2013-06-18 13:50 ` Michal Hocko 2013-06-25 2:27 ` Dave Chinner 2013-06-25 2:27 ` Dave Chinner 2013-06-26 8:15 ` Michal Hocko 2013-06-26 8:15 ` Michal Hocko 2013-06-26 23:24 ` Dave Chinner 2013-06-26 23:24 ` Dave Chinner 2013-06-27 14:54 ` Michal Hocko 2013-06-27 14:54 ` Michal Hocko 2013-06-28 8:39 ` Michal Hocko 2013-06-28 8:39 ` Michal Hocko 2013-06-28 14:31 ` Glauber Costa 2013-06-28 14:31 ` Glauber Costa 2013-06-28 15:12 ` Michal Hocko 2013-06-28 15:12 ` Michal Hocko 2013-06-29 2:55 ` Dave Chinner 2013-06-29 2:55 ` Dave Chinner 2013-06-30 18:33 ` Michal Hocko 2013-07-01 1:25 ` Dave Chinner 2013-07-01 1:25 ` Dave Chinner 2013-07-01 7:50 ` Michal Hocko 2013-07-01 7:50 ` Michal Hocko 2013-07-01 8:10 ` Dave Chinner 2013-07-01 8:10 ` Dave Chinner 2013-07-02 9:22 ` Michal Hocko 2013-07-02 12:19 ` Dave Chinner 2013-07-02 12:19 ` Dave Chinner 2013-07-02 12:44 ` Michal Hocko 2013-07-02 12:44 ` Michal Hocko 2013-07-03 11:24 ` Dave Chinner 2013-07-03 11:24 ` Dave Chinner 2013-07-03 14:08 ` Glauber Costa 2013-07-03 14:08 ` Glauber Costa 2013-07-04 16:36 ` Michal Hocko 2013-07-04 16:36 ` Michal Hocko 2013-07-08 12:53 ` Michal Hocko 2013-07-08 21:04 ` Andrew Morton 2013-07-08 21:04 ` Andrew Morton 2013-07-09 17:34 ` Glauber Costa 2013-07-09 17:34 ` Glauber Costa 2013-07-09 17:51 ` Andrew Morton 2013-07-09 17:51 ` Andrew Morton 2013-07-09 17:32 ` Glauber Costa 2013-07-09 17:32 ` Glauber Costa 2013-07-09 17:50 ` Andrew Morton 2013-07-09 17:50 ` Andrew Morton 2013-07-09 17:57 ` Glauber Costa 2013-07-09 17:57 ` Glauber Costa 2013-07-09 17:57 ` Michal Hocko 2013-07-09 17:57 ` Michal Hocko 2013-07-09 21:39 ` Andrew Morton 2013-07-09 21:39 ` Andrew Morton 2013-07-10 2:31 ` Dave Chinner 2013-07-10 2:31 ` Dave Chinner 2013-07-10 7:34 ` Michal Hocko 2013-07-10 7:34 ` Michal Hocko 2013-07-10 8:06 ` Michal Hocko 2013-07-10 8:06 ` Michal Hocko 2013-07-11 2:26 ` Dave Chinner 2013-07-11 2:26 ` Dave Chinner 2013-07-11 3:03 ` Andrew Morton 2013-07-11 3:03 ` Andrew Morton 2013-07-11 13:23 ` Michal Hocko 2013-07-11 13:23 ` Michal Hocko 2013-07-12 1:42 ` Hugh Dickins 2013-07-12 1:42 ` Hugh Dickins 2013-07-13 3:29 ` Dave Chinner 2013-07-13 3:29 ` Dave Chinner 2013-07-15 9:14 ` Michal Hocko 2013-07-15 9:14 ` Michal Hocko 2013-06-18 6:26 ` Glauber Costa 2013-06-18 8:25 ` Michal Hocko 2013-06-18 8:25 ` Michal Hocko 2013-06-19 7:13 ` Michal Hocko 2013-06-19 7:13 ` Michal Hocko 2013-06-19 7:35 ` Glauber Costa 2013-06-19 7:35 ` Glauber Costa 2013-06-19 8:52 ` Glauber Costa 2013-06-19 8:52 ` Glauber Costa 2013-06-19 13:57 ` Michal Hocko 2013-06-19 13:57 ` Michal Hocko 2013-06-19 14:02 ` Glauber Costa 2013-06-19 14:02 ` Glauber Costa 2013-06-19 14:28 ` Michal Hocko 2013-06-19 14:28 ` Michal Hocko 2013-06-20 14:11 ` Glauber Costa 2013-06-20 14:11 ` Glauber Costa 2013-06-20 15:12 ` Michal Hocko 2013-06-20 15:16 ` Michal Hocko 2013-06-20 15:16 ` Michal Hocko 2013-06-21 9:00 ` Michal Hocko 2013-06-21 9:00 ` Michal Hocko 2013-06-23 11:51 ` Glauber Costa 2013-06-23 11:51 ` Glauber Costa 2013-06-23 11:55 ` Glauber Costa 2013-06-25 2:29 ` Dave Chinner 2013-06-25 2:29 ` Dave Chinner 2013-06-26 8:22 ` Michal Hocko [this message] 2013-06-26 8:22 ` Michal Hocko 2013-06-18 8:19 ` Michal Hocko 2013-06-18 8:19 ` Michal Hocko 2013-06-18 8:21 ` Glauber Costa 2013-06-18 8:21 ` Glauber Costa 2013-06-18 8:26 ` Michal Hocko 2013-06-18 8:26 ` Michal Hocko
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