From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933475AbdDGPlB (ORCPT ); Fri, 7 Apr 2017 11:41:01 -0400 Received: from mail-pg0-f67.google.com ([74.125.83.67]:32932 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754220AbdDGPkx (ORCPT ); Fri, 7 Apr 2017 11:40:53 -0400 Date: Sat, 8 Apr 2017 00:40:47 +0900 From: Sergey Senozhatsky To: Peter Zijlstra Cc: Sergey Senozhatsky , Pavel Machek , Sergey Senozhatsky , Jan Kara , "Eric W. Biederman" , Ye Xiaolong , Steven Rostedt , Petr Mladek , Andrew Morton , Linus Torvalds , "Rafael J . Wysocki" , Greg Kroah-Hartman , Jiri Slaby , Len Brown , linux-kernel@vger.kernel.org, lkp@01.org Subject: Re: [printk] fbc14616f4: BUG:kernel_reboot-without-warning_in_test_stage Message-ID: <20170407154047.GB384@tigerII.localdomain> References: <20170403093152.GB15168@quack2.suse.cz> <20170406173306.GD10363@amd> <20170407044334.GA487@jagdpanzerIV.localdomain> <20170407071558.GA11792@amd> <20170407074634.GB1091@jagdpanzerIV.localdomain> <20170407081449.GA12859@amd> <20170407121021.GA379@jagdpanzerIV.localdomain> <20170407124455.GC4756@amd> <20170407151306.GA384@tigerII.localdomain> <20170407152304.bkbceqmg3kxeqvur@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170407152304.bkbceqmg3kxeqvur@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.8.0 (2017-02-23) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (04/07/17 17:23), Peter Zijlstra wrote: [..] > > we are looking at different typical setups :) serial console being 45 > > seconds behind logbuf does not surprise me anymore. > > That does sound like you're doing something wrong and should look at > reducing printk() more than anything else. yeah, 45sec is an extreme case that simply doesn't surprise me anymore ;) that's not a normal/usual delay, of course, we are not this mad. on average it's much better and may be not so far 2 seconds after all. a massive OOM report, of course, appends logbuf messages at a much higher rate than UART serial console can swallow, so the delay is getting larger, expectedly. and, no, I don't add any printk-s, I'm looking at the lockup reports -ss From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: multipart/mixed; boundary="===============3677879638192552111==" MIME-Version: 1.0 From: Sergey Senozhatsky To: lkp@lists.01.org Subject: Re: [printk] fbc14616f4: BUG:kernel_reboot-without-warning_in_test_stage Date: Sat, 08 Apr 2017 00:40:47 +0900 Message-ID: <20170407154047.GB384@tigerII.localdomain> In-Reply-To: <20170407152304.bkbceqmg3kxeqvur@hirez.programming.kicks-ass.net> List-Id: --===============3677879638192552111== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable On (04/07/17 17:23), Peter Zijlstra wrote: [..] > > we are looking at different typical setups :) serial console being 45 > > seconds behind logbuf does not surprise me anymore. > = > That does sound like you're doing something wrong and should look at > reducing printk() more than anything else. yeah, 45sec is an extreme case that simply doesn't surprise me anymore ;) that's not a normal/usual delay, of course, we are not this mad. on average it's much better and may be not so far 2 seconds after all. a massive OOM report, of course, appends logbuf messages at a much higher rate than UART serial console can swallow, so the delay is getting larger, expectedly. and, no, I don't add any printk-s, I'm looking at the lockup reports -ss --===============3677879638192552111==--