From: Dave Jones <davej@redhat.com>
To: David Rientjes <rientjes@google.com>
Cc: Sasha Levin <sasha.levin@oracle.com>,
khlebnikov@openvz.org, Andrew Morton <akpm@linux-foundation.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: mm: BUG: Bad rss-counter state
Date: Wed, 22 Jan 2014 20:52:41 -0500 [thread overview]
Message-ID: <20140123015241.GA947@redhat.com> (raw)
In-Reply-To: <alpine.DEB.2.02.1401221735450.26172@chino.kir.corp.google.com>
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
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WARNING: multiple messages have this Message-ID (diff)
From: Dave Jones <davej@redhat.com>
To: David Rientjes <rientjes@google.com>
Cc: Sasha Levin <sasha.levin@oracle.com>,
khlebnikov@openvz.org, Andrew Morton <akpm@linux-foundation.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: mm: BUG: Bad rss-counter state
Date: Wed, 22 Jan 2014 20:52:41 -0500 [thread overview]
Message-ID: <20140123015241.GA947@redhat.com> (raw)
In-Reply-To: <alpine.DEB.2.02.1401221735450.26172@chino.kir.corp.google.com>
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
next prev parent reply other threads:[~2014-01-23 2:23 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-23 1:07 mm: BUG: Bad rss-counter state Sasha Levin
2014-01-23 1:07 ` Sasha Levin
2014-01-23 1:39 ` David Rientjes
2014-01-23 1:39 ` David Rientjes
2014-01-23 1:52 ` Dave Jones [this message]
2014-01-23 1:52 ` Dave Jones
2014-01-23 2:16 ` Sasha Levin
2014-01-23 2:16 ` Sasha Levin
2014-01-23 2:21 ` Dave Jones
2014-01-23 2:21 ` Dave Jones
2014-01-23 3:14 ` Sasha Levin
2014-01-23 2:15 ` Sasha Levin
2014-01-23 2:15 ` Sasha Levin
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