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=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 9B865C35240 for ; Sun, 26 Jan 2020 23:32:27 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6F5F820720 for ; Sun, 26 Jan 2020 23:32:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="LEKyhSXo"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="XBDbUIra" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6F5F820720 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:Reply-To:List-Subscribe:List-Help: List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version: References:Message-ID:Subject:To:From:Date:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=jDJ2xBxNdT4BidkkdQcMVQ2infLJj4LlyAfLlO9gTsM=; b=LEKyhSXodiZs+I Rbengl182Mudp4bJTX4XuqH3oJ3EYHiacSvBrHz0xK8NMbMvkmmXjQgbYbxABt4UwDWWWxtn5ZVfb quzS2EpF54f+1j8aWE/NnZet1vRWmghg226+BNsDUhIZvJuMkNnaMqqEinQgsL27YWLu7Hk8dBXxL QhC/IKrI1v/2duFwvAfIHTLN6i7trbeCjwY1vRQG+J9KUR4XsAlSjwANf5O3pWEZ6X2GMxdYu0uSr 7URgoiFvl/7iTDDfxQUFOiNARh1GyHu8EIOqDxI+RCBrO++pT69vy5oaGVxAJuyGkKDIyQOPmtL74 q0XOnpaQ+7TLc5ASPxKw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1ivrOE-0004cW-P3; Sun, 26 Jan 2020 23:32:26 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1ivrOB-0004c8-W1 for linux-arm-kernel@lists.infradead.org; Sun, 26 Jan 2020 23:32:25 +0000 Received: from paulmck-ThinkPad-P72.home (199-192-87-166.static.wiline.com [199.192.87.166]) (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 5C8172070A; Sun, 26 Jan 2020 23:32:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580081543; bh=HLB3DylvqhRZUjuNAimZ9xQIJr3vfYsph79EU+v44AM=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=XBDbUIra8EdZU3tEIdgh9kjZX2vMcKornjr8VLP0zn2D7JJwzbSoEHbjVKZ9vIEt3 EEG8uBU/MRC7vnKBSO7cYcbAgFOyH/yPa18UDbEAPWa2KVsP2Ms1QPk3OgBNFV7oVO dBJOQaAjjYYAiVP6gNKQgxHEZ1RoKtJk09snvne8= Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id 09B95352279E; Sun, 26 Jan 2020 15:32:23 -0800 (PST) Date: Sun, 26 Jan 2020 15:32:23 -0800 From: "Paul E. McKenney" To: Waiman Long Subject: Re: [PATCH v9 0/5] Add NUMA-awareness to qspinlock Message-ID: <20200126233222.GA4840@paulmck-ThinkPad-P72> 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> <20200126153535.GL2935@paulmck-ThinkPad-P72> <20200126224245.GA22901@paulmck-ThinkPad-P72> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200126224245.GA22901@paulmck-ThinkPad-P72> User-Agent: Mutt/1.9.4 (2018-02-28) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200126_153224_075948_B50B5ABB X-CRM114-Status: GOOD ( 26.45 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: paulmck@kernel.org Cc: linux-arch@vger.kernel.org, guohanjun@huawei.com, Arnd Bergmann , Peter Zijlstra , dave.dice@oracle.com, jglauber@marvell.com, x86@kernel.org, Will Deacon , linux@armlinux.org.uk, linux-kernel@vger.kernel.org, Ingo Molnar , bp@alien8.de, hpa@zytor.com, Alex Kogan , steven.sistare@oracle.com, tglx@linutronix.de, daniel.m.jordan@oracle.com, linux-arm-kernel Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Sun, Jan 26, 2020 at 02:42:45PM -0800, Paul E. McKenney wrote: > On Sun, Jan 26, 2020 at 07:35:35AM -0800, Paul E. McKenney wrote: > > 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"... > > And after fixing that, plus adding the other three Kconfig options required > to enable this, I really do see "Enabling CNA spinlock" in the console log. > Yay! > > At the end of the 30-minute locktorture exclusive-lock run, I see this: > > Writes: Total: 572176565 Max/Min: 54167704/10878216 ??? Fail: 0 > > This is about a five-to-one ratio. Is this expected behavior, given a > single NUMA node on a single-socket system with 12 hardware threads? > > I will try reader-writer lock next. > > Again, should I be using qemu's -numa command-line option to create nodes? > If so, what would be a sane configuration given 12 CPUs and 512MB of > memory for the VM? If not, what is a good way to exercise CNA's NUMA > capabilities within a guest OS? And the reader-writer lock run also shows "Enabling CNA spinlock". Same hardware and same 30-minute duration. Writes: Total: 25556912 Max/Min: 3225161/1664621 Fail: 0 Reads : Total: 11530762 Max/Min: 1155679/794179 Fail: 0 These are both within a factor of two (1.9 and 1.5), hence no "???". Thanx, Paul _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel