From mboxrd@z Thu Jan 1 00:00:00 1970 From: Catalin Marinas Subject: Re: next-20090202: task kmemleak:763 blocked for more than 120 seconds. Date: Tue, 03 Feb 2009 12:31:44 +0000 Message-ID: <1233664304.1568.39.camel@pc1117.cambridge.arm.com> References: <20090202215740.GA26550@google.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from cam-admin0.cambridge.arm.com ([193.131.176.58]:54150 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752853AbZBCMbw (ORCPT ); Tue, 3 Feb 2009 07:31:52 -0500 In-Reply-To: <20090202215740.GA26550@google.com> Sender: linux-next-owner@vger.kernel.org List-ID: To: Mandeep Singh Baines Cc: =?ISO-8859-1?Q?Fr=E9d=E9ric?= Weisbecker , Alexander Beregalov , "linux-next@vger.kernel.org" , LKML On Mon, 2009-02-02 at 13:57 -0800, Mandeep Singh Baines wrote: > The hung_task timeout is now 480 seconds because of sys_sync: > > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=fb822db465bd9fd4208eef1af4490539b236c54e > > But are there are really any other tasks which call > schedule_timeout_uninterruptibl() for with a timeout >480 seconds? > > Right now kmemleak appears to be the only exception. (A quick grep didn't turn > anything up.) And it is trivial to change kmemleak to use INTERRUPTIBLE. > Might even be a nice feature. You could stop it faster that way. I changed the code as below as it makes more sense: --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -1044,6 +1044,7 @@ static int kmemleak_scan_thread(void *arg) while (!kthread_should_stop()) { struct kmemleak_object *object; + signed long timeout = jiffies_scan_wait; mutex_lock(&scan_mutex); @@ -1069,7 +1070,8 @@ static int kmemleak_scan_thread(void *arg) mutex_unlock(&scan_mutex); /* wait before the next scan */ - schedule_timeout_uninterruptible(jiffies_scan_wait); + while (timeout && !kthread_should_stop()) + timeout = schedule_timeout_interruptible(timeout); } pr_info("kmemleak: Automatic memory scanning thread ended\n"); -- Catalin