From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f69.google.com (mail-ed1-f69.google.com [209.85.208.69]) by kanga.kvack.org (Postfix) with ESMTP id 5ADAA6B446D for ; Mon, 26 Nov 2018 18:29:29 -0500 (EST) Received: by mail-ed1-f69.google.com with SMTP id c3so10104091eda.3 for ; Mon, 26 Nov 2018 15:29:29 -0800 (PST) Received: from outbound-smtp16.blacknight.com (outbound-smtp16.blacknight.com. [46.22.139.233]) by mx.google.com with ESMTPS id y33si1215475eda.109.2018.11.26.15.29.27 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 26 Nov 2018 15:29:27 -0800 (PST) Received: from mail.blacknight.com (pemlinmail05.blacknight.ie [81.17.254.26]) by outbound-smtp16.blacknight.com (Postfix) with ESMTPS id 919F51C2A16 for ; Mon, 26 Nov 2018 23:29:27 +0000 (GMT) Date: Mon, 26 Nov 2018 23:29:26 +0000 From: Mel Gorman Subject: Re: Hackbench pipes regression bisected to PSI Message-ID: <20181126232926.GS23260@techsingularity.net> References: <20181126133420.GN23260@techsingularity.net> <20181126160724.GA21268@cmpxchg.org> <20181126165446.GQ23260@techsingularity.net> <20181126173218.GA22640@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20181126173218.GA22640@cmpxchg.org> Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner Cc: Tejun Heo , Peter Zijlstra , linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org On Mon, Nov 26, 2018 at 12:32:18PM -0500, Johannes Weiner wrote: > > > > Bit late to notice but this switch should be in > > Documentation/admin-guide/kernel-parameters.txt. If you really want to > > match the automatic numa balancing switch then it also should be > > psi=[enable|disable] instead of psi_enable=[1|0] > > Done and done, thanks. Updated patch: > The following is a comparision using CONFIG_PSI=n as a baseline against your patch and a vanilla kernel 4.20.0-rc4 4.20.0-rc4 4.20.0-rc4 kconfigdisable-v1r1 vanilla psidisable-v1r1 Amean 1 1.3100 ( 0.00%) 1.3923 ( -6.28%) 1.3427 ( -2.49%) Amean 3 3.8860 ( 0.00%) 4.1230 * -6.10%* 3.8860 ( -0.00%) Amean 5 6.8847 ( 0.00%) 8.0390 * -16.77%* 6.7727 ( 1.63%) Amean 7 9.9310 ( 0.00%) 10.8367 * -9.12%* 9.9910 ( -0.60%) Amean 12 16.6577 ( 0.00%) 18.2363 * -9.48%* 17.1083 ( -2.71%) Amean 18 26.5133 ( 0.00%) 27.8833 * -5.17%* 25.7663 ( 2.82%) Amean 24 34.3003 ( 0.00%) 34.6830 ( -1.12%) 32.0450 ( 6.58%) Amean 30 40.0063 ( 0.00%) 40.5800 ( -1.43%) 41.5087 ( -3.76%) Amean 32 40.1407 ( 0.00%) 41.2273 ( -2.71%) 39.9417 ( 0.50%) It's showing that the vanilla kernel takes a hit (as the bisection indicated it would) and that disabling PSI by default is reasonably close in terms of performance for this particular workload on this particular machine so; Tested-by: Mel Gorman Thanks! -- Mel Gorman SUSE Labs