From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Christoph Lameter <cl@linux.com>,
LKML <linux-kernel@vger.kernel.org>,
linux-mm <linux-mm@kvack.org>,
Andrew Morton <akpm@linux-foundation.org>,
Pekka Enberg <penberg@kernel.org>, Matt Mackall <mpm@selenic.com>,
Thomas Gleixner <tglx@linutronix.de>,
RT <linux-rt-users@vger.kernel.org>,
Clark Williams <clark@redhat.com>, John Kacur <jkacur@gmail.com>,
"Luis Claudio R. Goncalves" <lgoncalv@redhat.com>
Subject: Re: [RFC][PATCH v2] slub: Keep page and object in sync in slab_alloc_node()
Date: Fri, 18 Jan 2013 13:42:42 +0900 [thread overview]
Message-ID: <20130118044242.GA18665@lge.com> (raw)
In-Reply-To: <1358468924.23211.69.camel@gandalf.local.home>
Hello, Steven.
On Thu, Jan 17, 2013 at 07:28:44PM -0500, Steven Rostedt wrote:
> In slab_alloc_node(), after the cpu_slab is assigned, if the task is
> preempted and moves to another CPU, there's nothing keeping the page and
> object in sync. The -rt kernel crashed because page was NULL and object
> was not, and the node_match() dereferences page. Even though the crash
> happened on -rt, there's nothing that's keeping this from happening on
> mainline.
>
> The easiest fix is to disable interrupts for the entire time from
> acquiring the current CPU cpu_slab and assigning the object and page.
> After that, it's fine to allow preemption.
How about this?
It's based on v3.8-rc3.
I'm not test this patch, yet.
Just for sharing my idea to fix a problem.
-----------------8<-----------------------
next prev parent reply other threads:[~2013-01-18 4:42 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-17 18:10 [RFC][PATCH] slub: Check for page NULL before doing the node_match check Steven Rostedt
2013-01-17 18:37 ` Steven Rostedt
2013-01-17 21:28 ` Christoph Lameter
2013-01-17 21:36 ` Eric Dumazet
2013-01-17 21:44 ` Steven Rostedt
2013-01-17 21:43 ` Steven Rostedt
2013-01-17 21:51 ` Christoph Lameter
2013-01-17 22:07 ` Steven Rostedt
2013-01-17 22:46 ` Steven Rostedt
2013-01-17 23:10 ` Steven Rostedt
2013-01-17 23:20 ` [RFC][PATCH] slub: Keep page and object in sync in slab_alloc_node() Steven Rostedt
2013-01-18 0:23 ` Steven Rostedt
2013-01-18 0:28 ` [RFC][PATCH v2] " Steven Rostedt
2013-01-18 4:42 ` Joonsoo Kim [this message]
2013-01-18 14:52 ` Christoph Lameter
2013-01-18 15:29 ` Steven Rostedt
2013-01-18 14:44 ` Christoph Lameter
2013-01-18 15:04 ` Steven Rostedt
2013-01-18 15:55 ` Steven Rostedt
2013-01-18 18:29 ` Christoph Lameter
2013-01-18 18:52 ` Steven Rostedt
2013-01-21 1:48 ` Christoph Lameter
2013-01-21 8:11 ` Joonsoo Kim
2013-01-21 12:19 ` Steven Rostedt
2013-01-18 18:23 ` Christoph Lameter
2013-01-18 15:09 ` [RFC][PATCH v3] " Steven Rostedt
2013-01-18 18:40 ` Christoph Lameter
2013-01-18 19:09 ` Eric Dumazet
2013-01-18 19:20 ` Steven Rostedt
2013-01-21 1:40 ` Christoph Lameter
2013-01-18 14:43 ` [RFC][PATCH] slub: Check for page NULL before doing the node_match check Christoph Lameter
[not found] ` <alpine.DEB.2.02.1301171547370.2774@gentwo.org>
2013-01-17 21:56 ` Christoph Lameter
2013-01-17 22:10 ` Steven Rostedt
2013-01-17 21:22 ` Christoph Lameter
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