From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754493Ab3FRIVp (ORCPT ); Tue, 18 Jun 2013 04:21:45 -0400 Received: from mail-la0-f51.google.com ([209.85.215.51]:56773 "EHLO mail-la0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754450Ab3FRIVl (ORCPT ); Tue, 18 Jun 2013 04:21:41 -0400 Date: Tue, 18 Jun 2013 12:21:33 +0400 From: Glauber Costa To: Michal Hocko Cc: Andrew Morton , Dave Chinner , linux-mm@kvack.org, LKML Subject: Re: linux-next: slab shrinkers: BUG at mm/list_lru.c:92 Message-ID: <20130618082132.GC20528@localhost.localdomain> References: <20130617141822.GF5018@dhcp22.suse.cz> <20130617151403.GA25172@localhost.localdomain> <20130617143508.7417f1ac9ecd15d8b2877f76@linux-foundation.org> <20130617223004.GB2538@localhost.localdomain> <20130618081931.GB13677@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130618081931.GB13677@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 On Tue, Jun 18, 2013 at 10:19:31AM +0200, Michal Hocko wrote: > On Tue 18-06-13 02:30:05, Glauber Costa wrote: > > On Mon, Jun 17, 2013 at 02:35:08PM -0700, Andrew Morton wrote: > [...] > > > The trace says shrink_slab_node->super_cache_scan->prune_icache_sb. So > > > it's inodes? > > > > > Assuming there is no memory corruption of any sort going on , let's > > check the code. nr_item is only manipulated in 3 places: > > > > 1) list_lru_add, where it is increased > > 2) list_lru_del, where it is decreased in case the user have voluntarily removed the > > element from the list > > 3) list_lru_walk_node, where an element is removing during shrink. > > > > All three excerpts seem to be correctly locked, so something like this > > indicates an imbalance. Either the element was never added to the > > list, or it was added, removed, and we didn't notice it. (Again, your > > backing storage is not XFS, is it? If it is , we have another user to > > look for) > > No this is ext3. But I can try to test with xfs as well if it helps. > [...] XFS won't help this, on the contrary. The reason I asked is because XFS uses list_lru for its internal structures as well. So it is actually preferred if you are reproducing this without it, so we can at least isolate that part. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx178.postini.com [74.125.245.178]) by kanga.kvack.org (Postfix) with SMTP id 1741D6B0032 for ; Tue, 18 Jun 2013 04:21:39 -0400 (EDT) Received: by mail-la0-f54.google.com with SMTP id ec20so3280651lab.13 for ; Tue, 18 Jun 2013 01:21:37 -0700 (PDT) Date: Tue, 18 Jun 2013 12:21:33 +0400 From: Glauber Costa Subject: Re: linux-next: slab shrinkers: BUG at mm/list_lru.c:92 Message-ID: <20130618082132.GC20528@localhost.localdomain> References: <20130617141822.GF5018@dhcp22.suse.cz> <20130617151403.GA25172@localhost.localdomain> <20130617143508.7417f1ac9ecd15d8b2877f76@linux-foundation.org> <20130617223004.GB2538@localhost.localdomain> <20130618081931.GB13677@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130618081931.GB13677@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Andrew Morton , Dave Chinner , linux-mm@kvack.org, LKML On Tue, Jun 18, 2013 at 10:19:31AM +0200, Michal Hocko wrote: > On Tue 18-06-13 02:30:05, Glauber Costa wrote: > > On Mon, Jun 17, 2013 at 02:35:08PM -0700, Andrew Morton wrote: > [...] > > > The trace says shrink_slab_node->super_cache_scan->prune_icache_sb. So > > > it's inodes? > > > > > Assuming there is no memory corruption of any sort going on , let's > > check the code. nr_item is only manipulated in 3 places: > > > > 1) list_lru_add, where it is increased > > 2) list_lru_del, where it is decreased in case the user have voluntarily removed the > > element from the list > > 3) list_lru_walk_node, where an element is removing during shrink. > > > > All three excerpts seem to be correctly locked, so something like this > > indicates an imbalance. Either the element was never added to the > > list, or it was added, removed, and we didn't notice it. (Again, your > > backing storage is not XFS, is it? If it is , we have another user to > > look for) > > No this is ext3. But I can try to test with xfs as well if it helps. > [...] XFS won't help this, on the contrary. The reason I asked is because XFS uses list_lru for its internal structures as well. So it is actually preferred if you are reproducing this without it, so we can at least isolate that part. -- 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: email@kvack.org