From mboxrd@z Thu Jan 1 00:00:00 1970 From: Viresh Kumar Subject: Re: System will not suspend with highest numbered CPU offline [REGRESSION][BISECTED] Date: Fri, 4 Sep 2015 20:12:41 +0530 Message-ID: <20150904144241.GJ29194@linux> References: <001401d0e691$302127b0$90637710$@net> <3237049.urJsZkC6Rf@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pa0-f51.google.com ([209.85.220.51]:36810 "EHLO mail-pa0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751661AbbIDOmq (ORCPT ); Fri, 4 Sep 2015 10:42:46 -0400 Received: by pacwi10 with SMTP id wi10so26335479pac.3 for ; Fri, 04 Sep 2015 07:42:45 -0700 (PDT) Content-Disposition: inline In-Reply-To: <3237049.urJsZkC6Rf@vostro.rjw.lan> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: "Rafael J. Wysocki" Cc: Doug Smythies , "'Rafael J. Wysocki'" , 'Saravana Kannan' , linux-pm@vger.kernel.org On 04-09-15, 16:59, 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? > > > 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? I wanted to give him some patch to debug it a bit more, but couldn't do that whole day. @Doug: Can you please enable DEBUG for cpufreq with this: diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile index 9fde14544ead..c09945aa7f17 100644 --- a/drivers/cpufreq/Makefile +++ b/drivers/cpufreq/Makefile @@ -1,3 +1,4 @@ +subdir-ccflags-y := -DDEBUG # CPUfreq core obj-$(CONFIG_CPU_FREQ) += cpufreq.o freq_table.o And give us the outputs of both successful and unsuccessful logs? + the values of both affected_cpus and related_cpus fields for all CPUs. -- viresh