From: Catalin Marinas <catalin.marinas@arm.com>
To: Sergey Senozhatsky <sergey.senozhatsky@mail.by>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>,
Ingo Molnar <mingo@elte.hu>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: kmemleak not tainted
Date: Tue, 07 Jul 2009 14:22:21 +0100 [thread overview]
Message-ID: <1246972941.9451.44.camel@pc1117.cambridge.arm.com> (raw)
In-Reply-To: <20090707131725.GB3238@localdomain.by>
On Tue, 2009-07-07 at 16:17 +0300, Sergey Senozhatsky wrote:
> > On Tue, 2009-07-07 at 14:51 +0300, Sergey Senozhatsky wrote:
> > > kernel: [ 1917.133154] INFO: RCU detected CPU 0 stall (t=485140/3000 jiffies)
[...]
> > What I think happens is that the kmemleak thread runs for several
> > seconds for scanning the memory and there may not be any context
> > switches. I have a patch to add more cond_resched() calls throughout the
> > kmemleak_scan() function which I hope will get merged.
[...]
> > I don't get any of these messages with CONFIG_PREEMPT enabled.
>
> It started with rc2-git1 (may be). Almost every scan ends with RCU pending.
Should I assume that CONFIG_PREEMPT is disabled on your system?
The branch with the pending kmemleak patches is below (I sent Linus a
pull request):
http://www.linux-arm.org/git?p=linux-2.6.git;a=shortlog;h=kmemleak
You can try the "Add more cond_resched() calls..." patch and see if it
makes any difference.
> Hm.. Something is broken...
> cat /.../kmemleak
> [ 7933.537868] ================================================
> [ 7933.537873] [ BUG: lock held when returning to user space! ]
> [ 7933.537876] ------------------------------------------------
> [ 7933.537880] cat/2897 is leaving the kernel with locks still held!
> [ 7933.537884] 1 lock held by cat/2897:
> [ 7933.537887] #0: (scan_mutex){+.+.+.}, at: [<c10f717c>] kmemleak_open+0x4c/0x80
That the "Do not acquire scan_mutex in kmemleak_open()" patch in the
same branch.
--
Catalin
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next prev parent reply other threads:[~2009-07-07 13:21 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-07 11:51 Sergey Senozhatsky
2009-07-07 12:47 ` Catalin Marinas
2009-07-07 13:17 ` Sergey Senozhatsky
2009-07-07 13:22 ` Catalin Marinas [this message]
2009-07-07 13:45 ` Sergey Senozhatsky
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