Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933287AbbGJSLE (ORCPT ); Fri, 10 Jul 2015 14:11:04 -0400 Received: from mail-wi0-f179.google.com ([209.85.212.179]:35264 "EHLO mail-wi0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932620AbbGJSLA (ORCPT ); Fri, 10 Jul 2015 14:11:00 -0400 Date: Fri, 10 Jul 2015 20:10:57 +0200 From: Frederic Weisbecker To: Christoph Lameter Cc: Oleg Nesterov , LKML , Rik van Riel , Andrew Morton Subject: Re: [PATCH 2/5] kmod: Use system_unbound_wq instead of khelper Message-ID: <20150710181055.GB26428@lerouge> References: <1436465237-22031-1-git-send-email-fweisbec@gmail.com> <1436465237-22031-3-git-send-email-fweisbec@gmail.com> <20150709224406.GA17528@redhat.com> <20150710134739.GA25078@lerouge> <20150710171208.GA26428@lerouge> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1122 Lines: 24 On Fri, Jul 10, 2015 at 12:52:39PM -0500, Christoph Lameter wrote: > On Fri, 10 Jul 2015, Frederic Weisbecker wrote: > > > No it's not much configurable. The works are scheduled on tasks that are > > node affine and you can't change that for system_unbound_wq. Only WQ_SYSFS > > workqueues can be overriden on their no_numa property but even there that's > > after the boot and most of the usermodehelper load goes on boot. > > Well then lets have at least one thread per NUMA node so that NUMA > affinity works? That's already the case. There is at least one thread per node for the workqueue cpumask. Note that nohz full is perfectly fine with that. The issue I'm worried about is the case where drivers spawn hundreds of jobs and it all happen on the same node because the kernel threads inherit the workqueue affinity, instead of the global affinity that khelper had. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/