From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pb0-f42.google.com (mail-pb0-f42.google.com [209.85.160.42]) by kanga.kvack.org (Postfix) with ESMTP id 7213B6B00B8 for ; Tue, 5 Nov 2013 22:04:29 -0500 (EST) Received: by mail-pb0-f42.google.com with SMTP id jt11so8443419pbb.1 for ; Tue, 05 Nov 2013 19:04:29 -0800 (PST) Received: from psmtp.com ([74.125.245.186]) by mx.google.com with SMTP id ul9si3971901pab.229.2013.11.05.19.04.26 for ; Tue, 05 Nov 2013 19:04:27 -0800 (PST) Received: by mail-wi0-f179.google.com with SMTP id hm4so3056565wib.12 for ; Tue, 05 Nov 2013 19:04:24 -0800 (PST) MIME-Version: 1.0 In-Reply-To: References: <1383693987-14171-1-git-send-email-snanda@chromium.org> From: Sameer Nanda Date: Tue, 5 Nov 2013 19:04:03 -0800 Message-ID: Subject: Re: [PATCH] mm, oom: Fix race when selecting process to kill Content-Type: multipart/alternative; boundary=f46d043c81de05431004ea79682b Sender: owner-linux-mm@kvack.org List-ID: To: David Rientjes Cc: Luigi Semenzato , Andrew Morton , mhocko@suse.cz, Johannes Weiner , rusty@rustcorp.com.au, linux-mm@kvack.org, linux-kernel@vger.kernel.org --f46d043c81de05431004ea79682b Content-Type: text/plain; charset=UTF-8 On Tue, Nov 5, 2013 at 5:27 PM, David Rientjes wrote: > On Tue, 5 Nov 2013, Luigi Semenzato wrote: > > > It's not enough to hold a reference to the task struct, because it can > > still be taken out of the circular list of threads. The RCU > > assumptions don't hold in that case. > > > > Could you please post a proper bug report that isolates this at the cause? > We've been running into this issue on Chrome OS. crbug.com/256326 has additional details. The issue manifests itself as a soft lockup. The kernel we've been seeing this on is 3.8. We have a pretty consistent repro currently. Happy to try out other suggestions for a fix. > > Thanks. > -- Sameer --f46d043c81de05431004ea79682b Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable



On Tue, Nov 5, 2013 at 5:27 PM, David Rientjes &l= t;rientjes@google.= com> wrote:
On Tue, 5 Nov 2013, Luigi Semenzato wrot= e:

> It's not enough to hold a reference to the task struct, because it= can
> still be taken out of the circular list of threads. =C2=A0The RCU
> assumptions don't hold in that case.
>

Could you please post a proper bug report that isolates this at the c= ause?

We've been running into this = issue on Chrome OS. crbug.com/256326 has additional=C2=A0
details. =C2=A0The issue manifests itself as a soft lockup.
<= div>

for a fix.
=C2=A0

Thanks.



--
Sameer --f46d043c81de05431004ea79682b-- -- 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