From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx156.postini.com [74.125.245.156]) by kanga.kvack.org (Postfix) with SMTP id 404056B005A for ; Fri, 8 Jun 2012 16:23:57 -0400 (EDT) Received: by mail-vc0-f176.google.com with SMTP id fo14so1569211vcb.35 for ; Fri, 08 Jun 2012 13:23:56 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: <1338405610-1788-1-git-send-email-pshelar@nicira.com> <20120608131045.90708bda.akpm@linux-foundation.org> Date: Fri, 8 Jun 2012 13:23:56 -0700 Message-ID: Subject: Re: [Resend PATCH v2] mm: Fix slab->page _count corruption. From: Pravin Shelar Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Lameter Cc: Andrew Morton , penberg@kernel.org, aarcange@redhat.com, linux-mm@kvack.org, abhide@nicira.com On Fri, Jun 8, 2012 at 1:15 PM, Christoph Lameter wrote: > On Fri, 8 Jun 2012, Andrew Morton wrote: > >> OK. =A0I assume this bug has been there for quite some time. > > Well the huge pages refcount tricks caused the issue. > >> How serious is it? =A0Have people been reporting it in real workloads? >> How to trigger it? =A0IOW, does this need -stable backporting? > > Possibly. If this patch is getting back-ported then we shld also do same for 5bf5f03c271907978 (mm: fix slab->page flags corruption) which fixes other issue related to slub and huge page sharing. > >> Also, someone forgot to document these: >> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 struct { >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 = =A0 unsigned inuse:16; >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 = =A0 unsigned objects:15; >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 = =A0 unsigned frozen:1; >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 }; > > So far I thouight that the field names are pretty clear on their own. > -- 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