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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E9CA4C77B7D for ; Mon, 15 May 2023 08:40:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232858AbjEOIk3 (ORCPT ); Mon, 15 May 2023 04:40:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56348 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229749AbjEOIk1 (ORCPT ); Mon, 15 May 2023 04:40:27 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E2080E1 for ; Mon, 15 May 2023 01:40:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=RD5vUeFE3A5d4FsldbQHnKJtFa6t2QWFhZv+yAemSbs=; b=ehBz+j3ahy4u5PW4uxa2uyGNJo EBFe6Q34nuEaAcRCI+tbeXc7I14zzi5e0u0+qZG7aqXj1MNfOu4KRMISLXOGqwnA5hH2j2eNrTkHu uQvvK793POjWSxg49Bbe9Huea69FbJY6OWwQVhEIhB0v3ZFTua6hfvAi2N1O7XtMkMCq+hB7KHr6a zLmj5NVEqXqcruefol8Zh/0kdINTJ9d0alQEcO5jwfieZwAbmNJOHWUD/XWacF58y3JIL6BVpFfeF KdBkyA4si0Bd8nM250rxBdgOPlkLy7SXTJXCnNvdpv+s8tyg9C137AV50ShsToAwqJmtGHX2cwYVL kPUWVCgg==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1pyTkW-00BQwB-2q; Mon, 15 May 2023 08:40:09 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 9F4963001E4; Mon, 15 May 2023 10:40:07 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 69766202FCE90; Mon, 15 May 2023 10:40:07 +0200 (CEST) Date: Mon, 15 May 2023 10:40:07 +0200 From: Peter Zijlstra To: kernel test robot Cc: Mathieu Desnoyers , oe-lkp@lists.linux.dev, lkp@intel.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, ying.huang@intel.com, feng.tang@intel.com, fengwei.yin@intel.com, aubrey.li@linux.intel.com, yu.c.chen@intel.com, Aaron Lu Subject: Re: [linus:master] [sched] af7f588d8f: will-it-scale.per_thread_ops -13.9% regression Message-ID: <20230515084007.GF4253@hirez.programming.kicks-ass.net> References: <202305151017.27581d75-yujie.liu@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <202305151017.27581d75-yujie.liu@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 15, 2023 at 03:00:44PM +0800, kernel test robot wrote: > Hello, > > kernel test robot noticed a -13.9% regression of will-it-scale.per_thread_ops on: > > commit: af7f588d8f7355bc4298dd1962d7826358fc95f0 ("sched: Introduce per-memory-map concurrency ID") > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master > > testcase: will-it-scale > test machine: 224 threads 2 sockets (Sapphire Rapids) with 256G memory > parameters: > > test: context_switch1 > cpufreq_governor: performance > > test-description: Will It Scale takes a testcase and runs it from 1 through to n parallel copies to see if the testcase will scale. It builds both a process and threads based test in order to see any differences between the two. > test-url: https://github.com/antonblanchard/will-it-scale > > In addition to that, the commit also has significant impact on the following tests: > > +------------------+----------------------------------------------------------------------------------------------------+ > | testcase: change | will-it-scale: will-it-scale.per_thread_ops -73.8% regression | > | test machine | 224 threads 2 sockets (Sapphire Rapids) with 256G memory | > | test parameters | cpufreq_governor=performance | > | | mode=thread | > | | nr_task=16 | > | | test=context_switch1 | > +------------------+----------------------------------------------------------------------------------------------------+ > | testcase: change | will-it-scale: will-it-scale.per_thread_ops -57.9% regression | > | test machine | 104 threads 2 sockets (Skylake) with 192G memory | > | test parameters | cpufreq_governor=performance | > | | mode=thread | > | | nr_task=16 | > | | test=context_switch1 | > +------------------+----------------------------------------------------------------------------------------------------+ > | testcase: change | will-it-scale: will-it-scale.per_thread_ops -85.0% regression | > | test machine | 104 threads 2 sockets (Skylake) with 192G memory | > | test parameters | cpufreq_governor=performance | > | | mode=thread | > | | nr_task=50% | > | | test=context_switch1 | > +------------------+----------------------------------------------------------------------------------------------------+ > | testcase: change | vm-scalability: vm-scalability.throughput -9.0% regression | > | test machine | 96 threads 2 sockets Intel(R) Xeon(R) Platinum 8260L CPU @ 2.40GHz (Cascade Lake) with 128G memory | > | test parameters | cpufreq_governor=performance | > | | runtime=300s | > | | size=2T | > | | test=shm-xread-seq-mt | > +------------------+----------------------------------------------------------------------------------------------------+ > > FYI, we noticed that commit 223baf9d17f2 (sched: Fix performance > regression introduced by mm_cid) fixed a sysbench regression, but > will-it-scale context_switch1 benchmark still saw a regression on this > fix commit. > > Furthermore, we applied the code diff in below link [1] on mainline, and > the will-it-scale score was restored to the original level before this > patch. > > [1] https://lore.kernel.org/lkml/d96164a6-c522-1bfc-8b37-333726cdc573@efficios.com/ > Right; so I'm thinking we can do that patch -- I'll try and get the whole lazy TLB thing sorted, but I'm not sure I can find the piece and quiet to think that over in a hurry :/