linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Tejun Heo <tj@kernel.org>
To: Chris Mason <chris.mason@oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>, LKML <linux-kernel@vger.kernel.org>
Subject: Re: cfq crashing on boot with CONFIG_DEBUG_PAGE_ALLOC (linus master)
Date: Tue, 17 Jan 2012 09:35:00 -0800	[thread overview]
Message-ID: <20120117173500.GA6762@google.com> (raw)
In-Reply-To: <20120117161024.GC30322@shiny>

On Tue, Jan 17, 2012 at 11:10:24AM -0500, Chris Mason wrote:
> Hi everyone,
> 
> Looks like cfq is using stale pages, I'm getting crashes on boot with
> CONFIG_DEBUG_PAGE_ALLOC enabled.  The oops leads to crashing in
> cfqq_type, and if you add some fuzz for inlining, it looks like we're
> here:
> 
> (gdb) list *cfq_insert_request+0x3f5
> 0xffffffff812683d8 is in cfq_insert_request (block/cfq-iosched.c:3131).
> 3126	
> 3127		/*
> 3128		 * workload type is changed, don't save slice, otherwise preempt
> 3129		 * doesn't happen
> 3130		 */
> 3131		if (cfqq_type(old_cfqq) != cfqq_type(cfqq))
> 3132			cfqq->cfqg->saved_workload_slice = 0;
> 3133	
> 3134		/*
> 3135		 * Put the new queue at the front of the of the current list,
> 
> It seems like the most likely reason is that old_cfqq was previously
> freed:
> 
>         struct cfq_queue *old_cfqq = cfqd->active_queue;

Does the following patch resolve the problem?

  http://article.gmane.org/gmane.linux.kernel.next/20340/raw

Thanks.

-- 
tejun

  reply	other threads:[~2012-01-17 17:35 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-17 16:10 cfq crashing on boot with CONFIG_DEBUG_PAGE_ALLOC (linus master) Chris Mason
2012-01-17 17:35 ` Tejun Heo [this message]
2012-01-17 17:59   ` Chris Mason
2012-01-17 18:35     ` Tejun Heo

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20120117173500.GA6762@google.com \
    --to=tj@kernel.org \
    --cc=axboe@kernel.dk \
    --cc=chris.mason@oracle.com \
    --cc=linux-kernel@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).