From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ie0-f178.google.com (mail-ie0-f178.google.com [209.85.223.178]) by kanga.kvack.org (Postfix) with ESMTP id 1F50E6B0035 for ; Wed, 22 Jan 2014 21:23:44 -0500 (EST) Received: by mail-ie0-f178.google.com with SMTP id x13so459167ief.23 for ; Wed, 22 Jan 2014 18:23:43 -0800 (PST) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTP id v3si1467150ice.85.2014.01.22.18.23.42 for ; Wed, 22 Jan 2014 18:23:43 -0800 (PST) Date: Wed, 22 Jan 2014 20:52:41 -0500 From: Dave Jones Subject: Re: mm: BUG: Bad rss-counter state Message-ID: <20140123015241.GA947@redhat.com> References: <52E06B6F.90808@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: David Rientjes Cc: Sasha Levin , khlebnikov@openvz.org, Andrew Morton , "linux-mm@kvack.org" , LKML On Wed, Jan 22, 2014 at 05:39:25PM -0800, David Rientjes wrote: > > While fuzzing with trinity running inside a KVM tools guest using latest -next > > kernel, > > I've stumbled on a "mm: BUG: Bad rss-counter state" error which was pretty > > non-obvious > > in the mix of the kernel spew (why?). > > > > It's not a fatal condition and there's only a few possible stack traces > that could be emitted during the exit() path. I don't see how we could > make it more visible other than its log-level which is already KERN_ALERT. > > > I've added a small BUG() after the printk() in check_mm(), and here's the full > > output: > > > > Worst place to add it :) At line 562 of kernel/fork.c in linux-next > you're going to hit BUG() when there may be other counters that are also > bad and they don't get printed. > > > [ 318.334905] BUG: Bad rss-counter state mm:ffff8801e6dec000 idx:0 val:1 > > So our mm has a non-zero MM_FILEPAGES count, but there's nothing that was > cited that would tell us what that is so there's not much to go on, unless > someone already recognizes this as another issue. Is this reproducible on > 3.13 or only on linux-next? Sasha, is this the current git tree version of Trinity ? (I'm wondering if yesterdays munmap changes might be tickling this bug). Dave -- 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