From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id 4AAE09000C1 for ; Tue, 26 Apr 2011 13:19:15 -0400 (EDT) Received: from mail-vw0-f41.google.com (mail-vw0-f41.google.com [209.85.212.41]) (authenticated bits=0) by smtp1.linux-foundation.org (8.14.2/8.13.5/Debian-3ubuntu1.1) with ESMTP id p3QHIgRs023721 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=FAIL) for ; Tue, 26 Apr 2011 10:18:43 -0700 Received: by vws4 with SMTP id 4so898827vws.14 for ; Tue, 26 Apr 2011 10:18:42 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20110426190918.01660ccf@neptune.home> References: <20110425180450.1ede0845@neptune.home> <20110425190032.7904c95d@neptune.home> <20110425203606.4e78246c@neptune.home> <20110425191607.GL2468@linux.vnet.ibm.com> <20110425231016.34b4293e@neptune.home> <20110425214933.GO2468@linux.vnet.ibm.com> <20110426081904.0d2b1494@pluto.restena.lu> <20110426112756.GF4308@linux.vnet.ibm.com> <20110426183859.6ff6279b@neptune.home> <20110426190918.01660ccf@neptune.home> From: Linus Torvalds Date: Tue, 26 Apr 2011 10:18:22 -0700 Message-ID: Subject: Re: 2.6.39-rc4+: Kernel leaking memory during FS scanning, regression? Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org List-ID: To: =?ISO-8859-1?Q?Bruno_Pr=E9mont?= , Ingo Molnar , Peter Zijlstra Cc: paulmck@linux.vnet.ibm.com, Mike Frysinger , KOSAKI Motohiro , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, "Paul E. McKenney" , Pekka Enberg On Tue, Apr 26, 2011 at 10:09 AM, Bruno Pr=E9mont wrote: > > Just in case, /proc/$(pidof rcu_kthread)/status shows ~20k voluntary > context switches and exactly one non-voluntary one. > > In addition when rcu_kthread has stopped doing its work > `swapoff $(swapdevice)` seems to block forever (at least normal shutdown > blocks on disabling swap device). > If I get to do it when I get back home I will manually try to swapoff > and take process traces with sysrq-t. That "exactly one non-voluntary one" sounds like the smoking gun. Normally SCHED_FIFO runs until it voluntarily gives up the CPU. That's kind of the point of SCHED_FIFO. Involuntary context switches happen when some higher-priority SCHED_FIFO process becomes runnable (irq handlers? You _do_ have CONFIG_IRQ_FORCED_THREADING=3Dy in your config too), and maybe there is a bug in the runqueue handling for that case. Ingo, do you have any tests for SCHED_FIFO scheduling? Particularly with UP and voluntary preempt? Linus -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org