From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752330AbaB0PYH (ORCPT ); Thu, 27 Feb 2014 10:24:07 -0500 Received: from moutng.kundenserver.de ([212.227.126.131]:57158 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751192AbaB0PYF (ORCPT ); Thu, 27 Feb 2014 10:24:05 -0500 Message-ID: <1393514533.28343.19.camel@marge.simpson.net> Subject: Re: [RFC PATCH] rcu: move SRCU grace period work to power efficient workqueue From: Mike Galbraith To: Frederic Weisbecker Cc: "Paul E. McKenney" , Kevin Hilman , Tejun Heo , Lai Jiangshan , Zoran Markovic , linux-kernel@vger.kernel.org, Shaibal Dutta , Dipankar Sarma Date: Thu, 27 Feb 2014 16:22:13 +0100 In-Reply-To: <20140227144331.GA19580@localhost.localdomain> References: <1391197986-12774-1-git-send-email-zoran.markovic@linaro.org> <52F8A51F.4090909@cn.fujitsu.com> <20140210184729.GL4250@linux.vnet.ibm.com> <20140212182336.GD5496@localhost.localdomain> <1392614801.5565.92.camel@marge.simpson.net> <20140227144331.GA19580@localhost.localdomain> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 X-Provags-ID: V02:K0:1R1R0ffJUN2Xc944U8U4hJOJqGxSauoCnlYm00Webu/ j8Zz1pIRjN4Omgpc/PaoU9DhQoLHLe+9wRl+p09o8zzraMtuhP VGQeD7aixxplo+e83cqnlXO7+LdLnDD4+uwJczHd1CrsR6Ng6K pXkb8Rv8VDl86rMCVL0a1YKTymlCSOQKlArT4qqnfqGUlOWPXq Vmy3gO0HAu0PRCu/FjN9J6uAXPuaB51k3ZsuxW5AalLWLLytun qG1Y7RdKLZp0wwkVLHKy+Wz4uB6IwSndLhXbN3m6eceez6CGEI PYyYuNA/xj1spkzozM5aJT1afLzpFkReYGFauPCs/b46cck1Ot DBiMltEy/Us8RBMwb0wgee55DO3/iYHCsLboTxdUP Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2014-02-27 at 15:43 +0100, Frederic Weisbecker wrote: > On Mon, Feb 17, 2014 at 06:26:41AM +0100, Mike Galbraith wrote: > > On Wed, 2014-02-12 at 19:23 +0100, Frederic Weisbecker wrote: > > > On Mon, Feb 10, 2014 at 10:47:29AM -0800, Paul E. McKenney wrote: > > > > On Mon, Feb 10, 2014 at 06:08:31PM +0800, Lai Jiangshan wrote: > > > > > Acked-by: Lai Jiangshan > > > > > > > > Thank you all, queued for 3.15. > > > > > > > > We should also have some facility for moving the SRCU workqueues to > > > > housekeeping/timekeeping kthreads in the NO_HZ_FULL case. Or does > > > > this patch already have that effect? > > > > > > Kevin Hilman and me plan to try to bring a new Kconfig option that could let > > > us control the unbound workqueues affinity through sysfs. > > > > Handing control to the user seemed like a fine thing, so I started > > making a boot option to enable it. Forcing WQ_SYSFS on at sysfs > > decision spot doesn't go well, init order matters :) Post init frobbing > > required if you want to see/frob all unbound. > > I'm curious about the details. Is that because some workqueues are registered > before sysfs is even initialized? Yeah. I put in a test, and told it if not ready, go get ready and flag yourself as having BTDT (one registration being plenty), but that only made a different explosion. Post-init rescan is definitely a better plan, it can't be worse :) -Mike