Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753397AbeAJSpM (ORCPT + 1 other); Wed, 10 Jan 2018 13:45:12 -0500 Received: from mail.kernel.org ([198.145.29.99]:58662 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753212AbeAJSpJ (ORCPT ); Wed, 10 Jan 2018 13:45:09 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7F61121724 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=rostedt@goodmis.org Date: Wed, 10 Jan 2018 13:45:04 -0500 From: Steven Rostedt To: Tejun Heo Cc: Petr Mladek , Sergey Senozhatsky , akpm@linux-foundation.org, linux-mm@kvack.org, Cong Wang , Dave Hansen , Johannes Weiner , Mel Gorman , Michal Hocko , Vlastimil Babka , Peter Zijlstra , Linus Torvalds , Jan Kara , Mathieu Desnoyers , Tetsuo Handa , rostedt@home.goodmis.org, Byungchul Park , Sergey Senozhatsky , Pavel Machek , linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 0/2] printk: Console owner and waiter logic cleanup Message-ID: <20180110134504.37aaa032@vmware.local.home> In-Reply-To: <20180110181459.GL3668920@devbig577.frc2.facebook.com> References: <20180110132418.7080-1-pmladek@suse.com> <20180110140547.GZ3668920@devbig577.frc2.facebook.com> <20180110130517.6ff91716@vmware.local.home> <20180110181252.GK3668920@devbig577.frc2.facebook.com> <20180110181459.GL3668920@devbig577.frc2.facebook.com> X-Mailer: Claws Mail 3.15.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On Wed, 10 Jan 2018 10:14:59 -0800 Tejun Heo wrote: > On Wed, Jan 10, 2018 at 10:12:52AM -0800, Tejun Heo wrote: > > Hello, Steven. > > > > So, everything else on your message, sure. You do what you have to > > do, but I really don't understand the following part, and this has > > been the main source of frustration in the whole discussion. > > > > On Wed, Jan 10, 2018 at 01:05:17PM -0500, Steven Rostedt wrote: > > > You on the other hand are showing unrealistic scenarios, and crying > > > that it's what you see in production, with no proof of it. > > > > I've explained the same scenario multiple times. Unless you're > > assuming that I'm lying, it should be amply clear that the scenario is > > unrealistic - we've been seeing them taking place repeatedly for quite > > a while. > > Oops, I meant to write "not unrealistic". Anyways, if you think I'm > lying, please let me know. I can ask others who have been seeing the > issue to join the thread. I don't believe you are lying. I believe you are interpreting one problem as another. I don't see this is a printk bug, I see it as a recursive OOM + net console bug. My patch is not trying to solve that, and I don't believe it should be solved via printk. I'm trying to solve the problem of printk spamming all CPUs causing a single CPU to lock up. That is a real bug that has been hit in various different scenarios, where there is no other underlying bug. This issue is a printk problem, and my solution solves it for printk. -- Steve