From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B4E5C2D0A8 for ; Wed, 23 Sep 2020 19:00:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E616206FB for ; Wed, 23 Sep 2020 19:00:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600887655; bh=q8SPyCYBoxajNHJ9kslUFkwc9l2D1wSjsod45ANj2AM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=ZuKl6FUBrne5iVn4MXKpQhAoAkTwtv4yazK5hlhtQi4EMiWy61aLEi0/SR+vXygVR OgDIijupUtahf3q3QPC2EXXGvir6Nlz7ZAKIsRsyRrBHDFrhy5KOkbfpidMoO9ae/o RQpuF2vfNK1/qIwpx2O0OwN24w/ah6SDrUvfDLBw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726762AbgIWTAy (ORCPT ); Wed, 23 Sep 2020 15:00:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:43870 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726419AbgIWTAx (ORCPT ); Wed, 23 Sep 2020 15:00:53 -0400 Received: from localhost (lfbn-ncy-1-588-162.w81-51.abo.wanadoo.fr [81.51.203.162]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DC5F2208B6; Wed, 23 Sep 2020 19:00:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600887653; bh=q8SPyCYBoxajNHJ9kslUFkwc9l2D1wSjsod45ANj2AM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QC5KzA8bb7fmb8EtS2jSwoE6+EShyG1IPvPuzi4k7j7kRPLEhrac+YlEfcgVfLskR pmSMMhCxArR+3ABTw55pgWSe66jcPErRQPyrBmiOgxWwd6BuBlb0EZZYxwE4i+PdKm HlW8vJv7W7Vvx+UTpPTezbtf4Ht1583gDmMjT3DA= Date: Wed, 23 Sep 2020 21:00:50 +0200 From: Frederic Weisbecker To: "Paul E. McKenney" Cc: LKML , Steven Rostedt , Mathieu Desnoyers , Lai Jiangshan , Joel Fernandes , Josh Triplett Subject: Re: [RFC PATCH 12/12] rcu: Nocb (de)activate through sysfs Message-ID: <20200923190050.GA1026@lenoir> References: <20200921124351.24035-1-frederic@kernel.org> <20200921124351.24035-13-frederic@kernel.org> <20200922002629.GS29330@paulmck-ThinkPad-P72> <20200923152745.GB31465@lenoir> <20200923154716.GP29330@paulmck-ThinkPad-P72> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200923154716.GP29330@paulmck-ThinkPad-P72> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 23, 2020 at 08:47:16AM -0700, Paul E. McKenney wrote: > On Wed, Sep 23, 2020 at 05:27:46PM +0200, Frederic Weisbecker wrote: > > On Mon, Sep 21, 2020 at 05:26:29PM -0700, Paul E. McKenney wrote: > > > On Mon, Sep 21, 2020 at 02:43:51PM +0200, Frederic Weisbecker wrote: > > > > Not for merge. > > > > > > > > Make nocb toggable for a given CPU using: > > > > /sys/devices/system/cpu/cpu*/hotplug/nocb > > > > > > > > This is only intended for those who want to test this patchset. The real > > > > interfaces will be cpuset/isolation and rcutorture. > > > > > > Excellent choice for testing in the near term! > > > > > > How does rcutorture fare with this series if an additional kthread toggles > > > offloading on and off continually? > > > > So yeah that would be the plan: having something that randomly toggles > > offloading from the RCU tests themselves. I'm not quite familiar with > > rcutorture internals yet though. > > If you supply a function that selects a CPU and does the toggle, I > can quickly and easily wire it into rcutorture. I of course have no > objection to your learning to do this yourself, but the offer stands. I gladly accept your proposal! This way I will integrate it in the set and start testing. The functions to call would be: void rcu_nocb_cpu_offload(int cpu); void rcu_nocb_cpu_deoffload(int cpu); > > > > All questions and concerns aside, excellent progress and nice work!!! > > > > Thanks! We are slowly making progress :) > > Better than quickly failing to make progress, to be sure! ;-) ;-) Thanks a lot!