From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755337AbYA1QLB (ORCPT ); Mon, 28 Jan 2008 11:11:01 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752650AbYA1QKx (ORCPT ); Mon, 28 Jan 2008 11:10:53 -0500 Received: from ogre.sisk.pl ([217.79.144.158]:35522 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752091AbYA1QKw (ORCPT ); Mon, 28 Jan 2008 11:10:52 -0500 From: "Rafael J. Wysocki" To: "Dmitry Adamushko" Subject: Re: [Regression] 2.6.24-git3: Major annoyance during suspend/hibernation on x86-64 (bisected) Date: Mon, 28 Jan 2008 17:08:47 +0100 User-Agent: KMail/1.9.6 (enterprise 20070904.708012) Cc: "Ingo Molnar" , "Steven Rostedt" , "Andrew Morton" , "Linus Torvalds" , LKML , "Peter Zijlstra" References: <200801272229.48955.rjw@sisk.pl> <200801280226.22013.rjw@sisk.pl> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200801281708.48054.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday, 28 of January 2008, Dmitry Adamushko wrote: > On 28/01/2008, Rafael J. Wysocki wrote: > > On Sunday, 27 of January 2008, Ingo Molnar wrote: > > > > > > * Rafael J. Wysocki wrote: > > > > > > > Hi, > > > > > > > > 2.6.24-git3 adds a 5 - 10 sec delay to the suspend and hibernation > > > > code paths (probably related to the disabling of nonboot CPUs), which > > > > is !@#$%^&*() annoying. > > > > > > > > It's 100% reproducible on my HP nx6325 and bisection idendified the > > > > following commit as the first bad one: > > > > > > > > commit 764a9d6fe4b52995c8aba277e3634385699354f4 > > > > Author: Steven Rostedt > > > > Date: Fri Jan 25 21:08:04 2008 +0100 > > > > > > > > sched: track highest prio task queued > > > > > > hm, this patch is a NOP, so it's weird that it has an effect. > > > > > > Do you have serial logging enabled perhaps? If the following WARN_ON() > > > triggers: > > > > > > + WARN_ON(p->prio < rq->rt.highest_prio); > > > > > > then perhaps that can cause a 5-10 seconds delay. (that's how much time > > > it takes to printk a warning on the slowest serial settings) > > > > > > but if you use suspend, then any such printks would be preserved in the > > > dmesg, right? If the WARN_ON() triggers, and if you remove it, do things > > > get faster? > > > > No, this isn't the WARN_ON(). > > > > > this does have the feel of being scheduling related, but are you > > > absolutely sure about the precise identity of the patch? > > > > Actually, not quite. That's why I have verified it and found that another > > patch is really responsible for the issue, namely: > > > > commit 82a1fcb90287052aabfa235e7ffc693ea003fe69 > > Author: Ingo Molnar > > Date: Fri Jan 25 21:08:02 2008 +0100 > > > > softlockup: automatically detect hung TASK_UNINTERRUPTIBLE tasks > > > > Reverting this commit (it reverts with some minor modifications) fixes the > > problem for me. > > What if you use the same kernel that triggers a problem and just disable > this new 'softlockup' functionality: > > echo 0 > /proc/sys/kernel/hung_task_timeout_secs > > does the problem disapear? No, it doesn't. The setting doesn't seem to have any effect on it. Thanks, Rafael