From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751616AbcFUTog (ORCPT ); Tue, 21 Jun 2016 15:44:36 -0400 Received: from mail-yw0-f193.google.com ([209.85.161.193]:36120 "EHLO mail-yw0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750744AbcFUToe (ORCPT ); Tue, 21 Jun 2016 15:44:34 -0400 Date: Tue, 21 Jun 2016 15:43:56 -0400 From: Tejun Heo To: Peter Zijlstra Cc: Gautham R Shenoy , Thomas Gleixner , Michael Ellerman , Abdul Haleem , Aneesh Kumar , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, kernel-team@fb.com Subject: Re: [PATCH 1/2] workqueue: Move wq_update_unbound_numa() to the beginning of CPU_ONLINE Message-ID: <20160621194356.GU3262@mtj.duckdns.org> References: <6b3c7059ec5d2d6157d23d619e4507692a42a5bd.1465311052.git.ego@linux.vnet.ibm.com> <20160615155350.GB24102@mtj.duckdns.org> <20160615192844.GA20301@in.ibm.com> <20160616193504.GB3262@mtj.duckdns.org> <20160621141231.GA30251@in.ibm.com> <20160621153651.GF3262@mtj.duckdns.org> <20160621193709.GT30154@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160621193709.GT30154@twins.programming.kicks-ass.net> User-Agent: Mutt/1.6.1 (2016-04-27) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 21, 2016 at 09:37:09PM +0200, Peter Zijlstra wrote: > Hurm.. So I've applied it, just to get this issue sorted, but I'm not > entirely sure I like it. > > I think I prefer ego's version because that makes it harder to get stuff > to run on !active,online cpus. I think we really want to be careful what > gets to run during that state. The original patch just did set_cpus_allowed one more time late enough so that the target kthread (in most cases) doesn't have to go through fallback rq selection afterwards. I don't know what the long term solution is but CPU_ONLINE callbacks should be able to bind kthreads to the new CPU one way or the other. Thanks. -- tejun