From mboxrd@z Thu Jan 1 00:00:00 1970 From: Omar Sandoval Subject: Re: suspend regression in 4.1-rc1 Date: Sun, 17 May 2015 22:18:51 -0700 Message-ID: <20150518051851.GA9591@mew> References: <20150517185041.GA5897@dhcp22.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pd0-f181.google.com ([209.85.192.181]:36680 "EHLO mail-pd0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750895AbbERFSx (ORCPT ); Mon, 18 May 2015 01:18:53 -0400 Received: by pdfh10 with SMTP id h10so133559832pdf.3 for ; Sun, 17 May 2015 22:18:53 -0700 (PDT) Content-Disposition: inline In-Reply-To: <20150517185041.GA5897@dhcp22.suse.cz> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Michal Hocko Cc: Linus Torvalds , Ulrich Obergfell , Don Zickus , Ingo Molnar , Andrew Morton , "Rafael J. Wysocki" , Kevin Hilman , Ulf Hansson , linux-pm@vger.kernel.org, LKML On Sun, May 17, 2015 at 08:50:41PM +0200, Michal Hocko wrote: > Hi, > s2ram broke after 4.1-rc1 for me. The second s2ram simply doesn't wake > up (fans turn on but the screen is off). I have even noticed fans > starting also while suspended in some instances (which was especially > annoying when it happened on the way home from work). > I've tried /sys/power/pm_test and the issue starts at processors mode. > Nothing really interesting shows up in the netconsole but I didn't get > to a more detailed testing there. > > I've tried to bisect this as 4.0 works reliably. This was tricky though > because the first bad commit is a merge: > > commit 1dcf58d6e6e6eb7ec10e9abc56887b040205b06f > Merge: 80dcc31fbe55 e4b0db72be24 > Author: Linus Torvalds > Date: Tue Apr 14 16:49:17 2015 -0700 > > Merge branch 'akpm' (patches from Andrew) > > The merge commit is empty and both 80dcc31fbe55 and e4b0db72be24 work > properly but the merge is bad. So it seems like some of the commits in > either branch has a side effect which needs other branch in order to > reproduce. > > So've tried to bisect ^80dcc31fbe55 e4b0db72be24 and merged 80dcc31fbe55 > in each step. This lead to: > > commit 195daf665a6299de98a4da3843fed2dd9de19d3a > Author: Ulrich Obergfell > Date: Tue Apr 14 15:44:13 2015 -0700 > > watchdog: enable the new user interface of the watchdog mechanism > > The patch doesn't revert because of follow up changes so I have reverted > all three: > 692297d8f968 ("watchdog: introduce the hardlockup_detector_disable() function") > b2f57c3a0df9 ("watchdog: clean up some function names and arguments") > 195daf665a62 ("watchdog: enable the new user interface of the watchdog mechanism") > > on top of my current Linus tree (4cfceaf0c087f47033f5e61a801f4136d6fb68c6) > and the issue is gone. I have hard time to understand what these 3 could have > to do with suspend path, though. > > Then I've tried to bisect the other branch and merge 195daf665a62 during > each step to find out which patch starts failing. This lead to an even > weirder commit a1e12da4796a ("perf tools: Add 'I' event modifier for > exclude_idle bit") but maybe I've just screwed something on the way. > > I will continue debugging tomorrow but any hints would be helpful. > -- > Michal Hocko > SUSE Labs The symptoms here are different, and the bisect indicates that it's completely unrelated, but just for kicks you could also try: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=533445c6e53368569e50ab3fb712230c03d523f3 -- Omar