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 65F40C35241 for ; Sat, 25 Jan 2020 04:58:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2FE3120838 for ; Sat, 25 Jan 2020 04:58:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579928327; bh=se8AI+drmz8YaJ/8zhHySxcdJx3cDLiDs/OjJa17Oco=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:List-ID: From; b=StB864jPtxyVSWgA/XH3WzExcZby6jtNeEmRMbKZnW3363IhJqzLYnOOOOVFdgfSA DvHVKHdkEWg/rBVNLUtpSeoBko8BCSRm3pLY3XIiXMR82XmaBR4yWplLJszI+aWo7o wbgVT9SSldcmBZBgN/eTJoQL/lKHV+gVQJNwppY0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729094AbgAYE6q (ORCPT ); Fri, 24 Jan 2020 23:58:46 -0500 Received: from mail.kernel.org ([198.145.29.99]:56164 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725821AbgAYE6p (ORCPT ); Fri, 24 Jan 2020 23:58:45 -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 32D382075E; Sat, 25 Jan 2020 04:58:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579928325; bh=se8AI+drmz8YaJ/8zhHySxcdJx3cDLiDs/OjJa17Oco=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=kWYruwuKFzmpVprbEiv42WnO1l8hPIhsYJNU87fNFTiwlnIhfPi7wZUzk+7FyHg0t vre9xtm/9e6IgK94Oz2vMRqqCgXVwRQ4V4L2CGyHGqPTraGzKuAiCjU3yHAP7L0KoH hFfWTERFAbBf41FQBHKC55IS0rkQ66hdbmergH+g= Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id 04EDD352018E; Fri, 24 Jan 2020 20:58:45 -0800 (PST) Date: Fri, 24 Jan 2020 20:58:45 -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: <20200125045844.GC2935@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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 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