From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760149AbcIYTH7 (ORCPT ); Sun, 25 Sep 2016 15:07:59 -0400 Received: from mail-wm0-f65.google.com ([74.125.82.65]:34749 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756330AbcIYTHz (ORCPT ); Sun, 25 Sep 2016 15:07:55 -0400 Subject: Re: thousands of kworker processes with 4.7.x and 4.8-rc* To: Tomasz Chmielewski , Mike Galbraith References: <35b2acf87bfeaf1d04f2cf3d10b99b6e@admin.virtall.com> <20acd5801291dff03ed56b63919b9249@admin.virtall.com> <1474639800.4025.29.camel@gmail.com> <50d06a3b797091821d190196b48e8d52@admin.virtall.com> Cc: LKML From: Nikolay Borisov Message-ID: <95eb1349-fcd4-4713-31fc-695c6255ae30@gmail.com> Date: Sun, 25 Sep 2016 22:07:52 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 25.09.2016 15:40, Tomasz Chmielewski wrote: > On 2016-09-25 18:29, Tomasz Chmielewski wrote: > >>> I'll try to bisect. >> >> OK, not a kernel regression, but some config change caused it. >> However, I'm not able to locate which change exactly. >> >> I'm attaching two configs which I've tried with 4.7.3 - one results in >> thousands of kworkers, and the other doesn't. Also included a diff >> between them. >> >> Any obvious changes I should try? > > The problem is the allocator. > > -CONFIG_SLUB=y > +CONFIG_SLAB=y > > > With SLUB, I'm getting a handful of kworker processes, as expected. > > With SLAB, I'm getting thousands of kworker processes. > > > Not sure if that's expected behaviour or not. Why don't you sample the stacks of some of those kworker processes to see if they are all executing a parituclar piece of work. That might help you narrow down where they originate from. Cat multiple /proc/$kworker-pid/stack files and see if a pattern emerges. Regards, Nikolay > > > Tomasz Chmielewski > https://lxadm.com > >