From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Doug Smythies" Subject: RE: System will not suspend with highest numbered CPU offline [REGRESSION][BISECTED] Date: Fri, 4 Sep 2015 08:26:20 -0700 Message-ID: <000301d0e726$0da7ab10$28f70130$@net> References: <001401d0e691$302127b0$90637710$@net> <3237049.urJsZkC6Rf@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from cmta11.telus.net ([209.171.16.84]:47986 "EHLO cmta11.telus.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759597AbbIDP0Y (ORCPT ); Fri, 4 Sep 2015 11:26:24 -0400 In-Reply-To: <3237049.urJsZkC6Rf@vostro.rjw.lan> Content-Language: en-ca Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: "'Rafael J. Wysocki'" Cc: 'Viresh Kumar' , "'Rafael J. Wysocki'" , 'Saravana Kannan' , linux-pm@vger.kernel.org On 2015.09.04 08:00 Rafael J. Wysocki wrote: > On Thursday, September 03, 2015 02:40:43 PM Doug Smythies wrote: >> As of, or about, Kernel 4.2RC1 if I take my highest numbered >> CPU offline (7 in my case), the system will not suspend. > Does "will not suspend" mean that the suspend will fail with an error > or will it crash or hang or something else? Something else: Nothing at all happens, no error, no crash, no hang, no log entries (at least that I have been able to find). I use the "sudo pm-suspend" command, and it is as if it is a no-op. doug@s15:/sys/devices/system/cpu$ cat /sys/devices/system/cpu/cpu*/online 1 1 1 1 1 1 0 Someone suggested to me that I have to take the core offline, not just the 1 of 2 CPUs on the same core. However it makes no difference, and CPU 3 offline by itself works fine. >> The issue persists through Kernel 4.2. >> This is on my test computer with an i7-2600K. >> I do not normally use suspend on this computer, >> but was doing so while working on a bug report. >> >> The kernel was bisected, and the result was: >> >> $ git bisect bad >> 87549141d516aee71d511138e27117c41e8aef68 is the first bad commit >> commit 87549141d516aee71d511138e27117c41e8aef68 >> Author: Viresh Kumar >> Date: Wed Jun 10 02:13:21 2015 +0200 >> >> cpufreq: Stop migrating sysfs files on hotplug >> >> See also several e-mails with the above subject line >> between June 8th and 10th. >> >> With any other combination of taking CPUs offline, >> not including CPU 7, suspend seems to work properly. > Well, we'll need to debug it some. > Can you please check what's in the > /sys/devices/system/cpu/cpuX/cpufreq/related_cpus > files for all CPUs on your system? doug@s15:/sys/devices/system/cpu$ cat cpu?/cpufreq/related_cpus 0 1 2 3 4 5 6 7