From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932385AbcGLJiJ (ORCPT ); Tue, 12 Jul 2016 05:38:09 -0400 Received: from mail-pf0-f194.google.com ([209.85.192.194]:34241 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932221AbcGLJiH (ORCPT ); Tue, 12 Jul 2016 05:38:07 -0400 Date: Tue, 12 Jul 2016 18:38:05 +0900 From: Sergey Senozhatsky To: Viresh Kumar Cc: Jan Kara , Sergey Senozhatsky , Tejun Heo , Greg Kroah-Hartman , Linux Kernel Mailing List , vlevenetz@mm-sol.com, vaibhav.hiremath@linaro.org, alex.elder@linaro.org, johan@kernel.org, akpm@linux-foundation.org, rostedt@goodmis.org, Sergey Senozhatsky Subject: Re: [Query] Preemption (hogging) of the work handler Message-ID: <20160712093805.GA498@swordfish> References: <20160701165959.GR12473@ubuntu> <20160701172232.GD28719@htj.duckdns.org> <20160706182842.GS2671@ubuntu> <20160711102603.GI12410@quack2.suse.cz> <20160711154438.GA528@swordfish> <20160711223501.GI4695@ubuntu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160711223501.GI4695@ubuntu> User-Agent: Mutt/1.6.2 (2016-07-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On (07/11/16 15:35), Viresh Kumar wrote: [..] > Sometimes, the platform doesn't come back after suspend. I have tried > enabling no-console-suspend and the last line it prints is: > > Disabling non-boot CPUs > > And nothing after that at all. We have to forcefully reboot the phone > after that. Moving the prints to they synchronous way (using > echo 1 > /sys/module/printk/parameters/synchronous), fixes that issue. hm... I'll take a look. > So, the asynchronous printing have a issue that only we are hitting. > It looks like that all the CPUs are gone except CPU0 and that CPU is > hogged by the printk thread to print stuff as well as to suspend the > system, and something eventually gets wrong. -ss