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=-2.6 required=3.0 tests=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 CDCB7C2D0DB for ; Sun, 26 Jan 2020 15:35:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9E12A2083E for ; Sun, 26 Jan 2020 15:35:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580052937; bh=wNZuYpHo/oqB810XSYgXonQ7QrqECablZ/abB2+Rxq4=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:List-ID: From; b=YGqI1u5tClcGpj4wIJGvz6ceywuZtxYMWvr13hoDuy4SVxykShu/62o4rDpB+yLBh hVjXGLE/uZvkAFhK6t0qPF+YqMmr9YBGFeAwxlaTpmFVSigWLAnfSY7z/z78wdjH2x 1OJsv3/5HtJSnimr2o1h6yNdk53QSXVKqc1jh2SA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726771AbgAZPfh (ORCPT ); Sun, 26 Jan 2020 10:35:37 -0500 Received: from mail.kernel.org ([198.145.29.99]:57562 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725908AbgAZPfg (ORCPT ); Sun, 26 Jan 2020 10:35:36 -0500 Received: from paulmck-ThinkPad-P72.home (50-39-105-78.bvtn.or.frontiernet.net [50.39.105.78]) (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 2EAA12071A; Sun, 26 Jan 2020 15:35:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580052936; bh=wNZuYpHo/oqB810XSYgXonQ7QrqECablZ/abB2+Rxq4=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=eBkcLRR/OVOxK9jF4dAE0VVVJJGuBwoL10Xxa8stXLh38IkJ21JBqYg4pSeBn/9OX Kyf360tAyg43NBsr4G3IyY4D1KKiLXCcEc6kEPqhho9c6c9w9xOMb7y1xEH2f+v4v2 FEuL2in2eYunSEnck9fUMP3oOGi950PTouWTQZx0= Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id 070B7352277B; Sun, 26 Jan 2020 07:35:36 -0800 (PST) Date: Sun, 26 Jan 2020 07:35:36 -0800 From: "Paul E. McKenney" To: Waiman Long Cc: Alex Kogan , linux@armlinux.org.uk, Peter Zijlstra , Ingo Molnar , Will Deacon , Arnd Bergmann , linux-arch@vger.kernel.org, linux-arm-kernel , linux-kernel@vger.kernel.org, tglx@linutronix.de, bp@alien8.de, hpa@zytor.com, x86@kernel.org, guohanjun@huawei.com, jglauber@marvell.com, dave.dice@oracle.com, steven.sistare@oracle.com, daniel.m.jordan@oracle.com Subject: Re: [PATCH v9 0/5] Add NUMA-awareness to qspinlock Message-ID: <20200126153535.GL2935@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org References: <20200115035920.54451-1-alex.kogan@oracle.com> <20200124222434.GA7196@paulmck-ThinkPad-P72> <6AAE7FC6-F5DE-4067-8BC4-77F27948CD09@oracle.com> <20200125005713.GZ2935@paulmck-ThinkPad-P72> <02defadb-217d-7803-88a1-ec72a37eda28@redhat.com> <20200125045844.GC2935@paulmck-ThinkPad-P72> <967f99ee-b781-43f4-d8ba-af83786c429c@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <967f99ee-b781-43f4-d8ba-af83786c429c@redhat.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jan 25, 2020 at 02:41:39PM -0500, Waiman Long wrote: > On 1/24/20 11:58 PM, Paul E. McKenney wrote: > > On Fri, Jan 24, 2020 at 09:17:05PM -0500, Waiman Long wrote: > >> On 1/24/20 8:59 PM, Waiman Long wrote: > >>>> You called it! I will play with QEMU's -numa argument to see if I can get > >>>> CNA to run for me. Please accept my apologies for the false alarm. > >>>> > >>>> Thanx, Paul > >>>> > >>> CNA is not currently supported in a VM guest simply because the numa > >>> information is not reliable. You will have to run it on baremetal to > >>> test it. Sorry for that. > >> Correction. There is a command line option to force CNA lock to be used > >> in a VM. Use the "numa_spinlock=on" boot command line parameter. > > As I understand it, I need to use a series of -numa arguments to qemu > > combined with the numa_spinlock=on (or =1) on the kernel command line. > > If the kernel thinks that there is only one NUMA node, it appears to > > avoid doing CNA. > > > > Correct? > > > > Thanx, Paul > > > In auto-detection mode (the default), CNA will only be turned on when > paravirt qspinlock is not enabled first and there are at least 2 numa > nodes. The "numa_spinlock=on" option will force it on even when both of > the above conditions are false. Hmmm... Here is my kernel command line taken from the console log: console=ttyS0 locktorture.onoff_interval=0 numa_spinlock=on locktorture.stat_interval=15 locktorture.shutdown_secs=1800 locktorture.verbose=1 Yet the string "Enabling CNA spinlock" does not appear. Ah, idiot here needs to enable CONFIG_NUMA_AWARE_SPINLOCKS in his build. Trying again with "--kconfig "CONFIG_NUMA_AWARE_SPINLOCKS=y"... Thanx, Paul