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=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 6C23DC38A2A for ; Fri, 8 May 2020 11:05:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3F117208CA for ; Fri, 8 May 2020 11:05:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="VpT91/Q4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726951AbgEHLFx (ORCPT ); Fri, 8 May 2020 07:05:53 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:58415 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726598AbgEHLFx (ORCPT ); Fri, 8 May 2020 07:05:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1588935951; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=OyMx9aVUSu/DmTgJ6+OJtrR2qw2jHoUm0ebz2iMPXwE=; b=VpT91/Q4XjDtisLR7u/EHS8Z8K0VrENrDfN/zFtURUCbDXn1OY4uS+T4QSpeZDUxtmjZ1A 45Vw1Z6kiVr4WqsVbQw9b8gCXFaB+3q1N+xKaYA6tl9YC4fUh/7qU/b3gowYkAxXzhc5Ff K3dMP5M4SZZjYR3RDHr/kpTHaA+5ImA= Received: from mail-ej1-f70.google.com (mail-ej1-f70.google.com [209.85.218.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-220-4dTSnNzXNUG5belI-mozug-1; Fri, 08 May 2020 07:05:49 -0400 X-MC-Unique: 4dTSnNzXNUG5belI-mozug-1 Received: by mail-ej1-f70.google.com with SMTP id j21so594711ejs.1 for ; Fri, 08 May 2020 04:05:49 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=OyMx9aVUSu/DmTgJ6+OJtrR2qw2jHoUm0ebz2iMPXwE=; b=kf+IP4FA1IfpxNBzmwp2B8rwZIcqhTCCrw9FGhYM3sxY7IfKOuHfMcXnZS4LI0Pi0u /Nc34QKaL97U2707UneopbL8/Ae04r9zVweMJQ7MfM7T1mUt94hgQtddWyPmP7qylVEZ ixlRpwymkCwH/SH9PsoUmjJpvHaGJO0cTeUmlUFtmF2sv1UIKuDRrFzN6fAEGguoAGGB gMHcGHr+8bg14llmuyio5x95q67MaQNMhcsrILhBX4IU6dn/liks3J7tuM1SjANkaEL0 bCq6VkA9YXTOe9N0MUFURzi/l3ULLBfxaEeayO1El8LSxnWFN0JV0BGqh/XBgF5PWy67 5e4g== X-Gm-Message-State: AGi0PuYEupwmlvkCZGthjmeDdeuTKNv8YqFy5YG416E/U86wJ8QRl1t8 clM1CboMpf27DoIl/TFrOSHxQfMSw7JeWscNqMW+ZDETZDJUi6HyaqHrDykkAtekdhxMoxNgc+4 ZoqyeWWTG5UuVQCJE0YsanUZjne3u8bnhudL6y1Rn X-Received: by 2002:a17:906:4919:: with SMTP id b25mr1423997ejq.280.1588935947994; Fri, 08 May 2020 04:05:47 -0700 (PDT) X-Google-Smtp-Source: APiQypIrdmBnsLT6dHwjgKDq2PccbrBwdIiUdqtb64bL67SMEXzSd8xZvWOqjvyRgApQPG1S2PuHs0RUAp9y3JdAjZ4= X-Received: by 2002:a17:906:4919:: with SMTP id b25mr1423980ejq.280.1588935947734; Fri, 08 May 2020 04:05:47 -0700 (PDT) MIME-Version: 1.0 References: <20200312214736.GA3818@techsingularity.net> <20200320152251.GC3818@techsingularity.net> <20200320163843.GD3818@techsingularity.net> <20200507155422.GD3758@techsingularity.net> <20200508092212.GE3758@techsingularity.net> In-Reply-To: <20200508092212.GE3758@techsingularity.net> From: Jirka Hladky Date: Fri, 8 May 2020 13:05:36 +0200 Message-ID: Subject: Re: [PATCH 00/13] Reconcile NUMA balancing decisions with the load balancer v6 To: linux-kernel Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Mel, thanks for hints! We will try it. @Phil - could you please prepare a kernel build for me to test? Thank you! Jirka On Fri, May 8, 2020 at 11:22 AM Mel Gorman wrote: > > On Thu, May 07, 2020 at 06:29:44PM +0200, Jirka Hladky wrote: > > Hi Mel, > > > > we are not targeting just OMP applications. We see the performance > > degradation also for other workloads, like SPECjbb2005 and > > SPECjvm2008. Even worse, it also affects a higher number of threads. > > For example, comparing 5.7.0-0.rc2 against 5.6 kernel, on 4 NUMA > > server with 2x AMD 7351 CPU, we see performance degradation 22% for 32 > > threads (the system has 64 CPUs in total). We observe this degradation > > only when we run a single SPECjbb binary. When running 4 SPECjbb > > binaries in parallel, there is no change in performance between 5.6 > > and 5.7. > > > > Minimally I suggest confirming that it's really due to > adjust_numa_imbalance() by making the function a no-op and retesting. > I have found odd artifacts with it but I'm unsure how to proceed without > causing problems elsehwere. > > For example, netperf on localhost in some cases reported a regression > when the client and server were running on the same node. The problem > appears to be that netserver completes its work faster when running > local and goes idle more regularly. The cost of going idle and waking up > builds up and a lower throughput is reported but I'm not sure if gaming > an artifact like that is a good idea. > > > That's why we are asking for the kernel tunable, which we would add to > > the tuned profile. We don't expect users to change this frequently but > > rather to set the performance profile once based on the purpose of the > > server. > > > > If you could prepare a patch for us, we would be more than happy to > > test it extensively. Based on the results, we can then evaluate if > > it's the way to go. Thoughts? > > > > I would suggest simply disabling that function first to ensure that is > really what is causing problems for you. > > -- > Mel Gorman > SUSE Labs > -- -Jirka