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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 28E66C02198 for ; Tue, 11 Feb 2025 02:15:07 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 901AD28000A; Mon, 10 Feb 2025 21:15:06 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 8B18F280008; Mon, 10 Feb 2025 21:15:06 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7789328000A; Mon, 10 Feb 2025 21:15:06 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 5C06A280008 for ; Mon, 10 Feb 2025 21:15:06 -0500 (EST) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 0D426A0AEC for ; Tue, 11 Feb 2025 02:15:06 +0000 (UTC) X-FDA: 83106046212.01.3C3E706 Received: from mail-qt1-f169.google.com (mail-qt1-f169.google.com [209.85.160.169]) by imf06.hostedemail.com (Postfix) with ESMTP id 1F9BB18000D for ; Tue, 11 Feb 2025 02:15:03 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=gourry.net header.s=google header.b=Exetvbbe; spf=pass (imf06.hostedemail.com: domain of gourry@gourry.net designates 209.85.160.169 as permitted sender) smtp.mailfrom=gourry@gourry.net; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1739240104; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=H2gxFs3tfFYKHyVYTpvL17LkDysO2OVKxxWn8KTpAXk=; b=ywjg88csAPrmgpTDnMCeRVJQbwZUAZdYZEZ4DJmuPc3RbV8lX/M5hdszpp6uht/uHrak92 ph55lQRCScSmQE9hduTY0ACQH0AgFI5lTgQd2tJqeSApnIabFPs4cVnScB4uswXYpp1AfR 6fAd2EpAPPbP1fsL3nRi8zM2/Vip55M= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=pass header.d=gourry.net header.s=google header.b=Exetvbbe; spf=pass (imf06.hostedemail.com: domain of gourry@gourry.net designates 209.85.160.169 as permitted sender) smtp.mailfrom=gourry@gourry.net; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1739240104; a=rsa-sha256; cv=none; b=Ajo01fGxx7K2N4Y8qRRpKhkh04x70yLr2PVJdg3Npng3jIpwC/6F4WZDouULbuHo+EP4WT 6Fz8uJOhUwka9NK4o3Wz4iBzCXgF75O3Z7OFN2d55Wsy28OSQyjM+LQ1FLqbPR3REmCZlV EVE3ZbbsZSBjQG9qWM4RSUCyzHNyk7o= Received: by mail-qt1-f169.google.com with SMTP id d75a77b69052e-4718d989c1cso30498861cf.2 for ; Mon, 10 Feb 2025 18:15:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gourry.net; s=google; t=1739240103; x=1739844903; darn=kvack.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=H2gxFs3tfFYKHyVYTpvL17LkDysO2OVKxxWn8KTpAXk=; b=Exetvbbe1lPSx+iGLOSK0qgWtxdqDiHUXvrD4k89d5swY6d8K4C3jWdUGt6KsQxotn J9W6+zW58Xx2UjRgKDg9YHYBmB9nJLleTi2mue6l5wpnrfX0pQt7VmjZQprBmUsIsrLW g4M9oYWmIumyLCwOjxN/rvYrL+WcfVo8QCJ94cWHU3y77Jem2m8jbYKeAQa26+xPjgRb QLrr12WYEYPj7yxDZYfj/bgb5SXLCyhgVLbtHSXVkfmuqATGh9WgwREfLRmWunRztpQw uX6PsXA7uryyh1VlqzZeyXB95bqqh68mw31DeUkkZfWVVfUyKBugw4EPsVu5mQwbBG9R w0aQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1739240103; x=1739844903; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=H2gxFs3tfFYKHyVYTpvL17LkDysO2OVKxxWn8KTpAXk=; b=C/DjtMaaqOI5nhwM4s/FKNr/YRSL0hJ59ONMT62XiGz/SqP2LXrxujevkI6nw+W8y2 TwW7kOjmuIXQMLbIoa1XRoMAAE8P3C20V1KRy3kajJAiPsszfYgD5kVNE0gEd6ZI4t7a yn7aCzaZ94qfKb05Ipg8PRCYNFl83iNF51kGYin7yDNAGKO/dUpfw2GeE1XlIFkHFX+1 ZWXZ2qQmGGnHCFbP19jrPg4PIjPhmE4tpRs9OdfUxW02Jo2ghixysYcmREKxIyh9Lspe wmvinnX9Z5EEbaJCZB3T2609mnhDHQltcRyjWRaPtyBvKFb2JduN+nkAqZfLiAHysn/E lU3Q== X-Forwarded-Encrypted: i=1; AJvYcCWp27DmKIfkoMVWpBPSls8VABMbkcMTmHLEYxb1p8mxzeLDPMCdHrCCfybj0aBhw+3ZO3OO17YvpQ==@kvack.org X-Gm-Message-State: AOJu0YxrjpYCpq/OeQl/OqHo9GJEBN4AH5CjzNfleJNxxAN4fz9IFj/I gIK73KbSaYHyExk5n2DUUckOGo8z579zwJWFEAAIAJLY73npFZJJTdTCrPFcmqeNmLq+UqXB1ZQ X X-Gm-Gg: ASbGncvsoonzs/bFOCUAb31P3X3WWg8HzTkKSX7HaOJ15N5z8Tre/IwP94hIQ+U2g9h 3XdLWzYcJlEtfKEsxG9HTJVYqdCbqsWWHZII9r6x6rx+PzdCtFjT966+EJUpEgYP6m4tZDuqiSI YLaSMwr1GxVGD1D8Wr7QLopHtYNq7CUlGq1Zzf7R/QzvbrUivOTOThNfA1S4QKgyqTrlmlwW2yK uYPiPCH3hYUIEoHiiKpugWd6we9kzf+hLL0+wRwiXVjKEzbanFSUcxEFU+x8F02Rj/rFGbhcQ2T hvM4nX1Ce64WQNz66rTJSMqwGo9GfD8/ONaNkKEDWmyA4W/2Pr4NuajG4pn7oFBqewKguZAnzQ= = X-Google-Smtp-Source: AGHT+IEfvXpY/tplh7KS1jPYCPst0iTC1lg9LCaiKWRQOE2BUPYfi4dAoAFQOz0a/z0irSMYiTy/QA== X-Received: by 2002:a05:622a:30b:b0:471:a083:f3e4 with SMTP id d75a77b69052e-471a083f4b5mr31004531cf.4.1739240103182; Mon, 10 Feb 2025 18:15:03 -0800 (PST) Received: from gourry-fedora-PF4VCD3F (pool-173-79-56-208.washdc.fios.verizon.net. [173.79.56.208]) by smtp.gmail.com with ESMTPSA id af79cd13be357-7c041dec2e9sm604168685a.20.2025.02.10.18.15.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 10 Feb 2025 18:15:02 -0800 (PST) Date: Mon, 10 Feb 2025 21:14:59 -0500 From: Gregory Price To: Andrew Morton Cc: Joshua Hahn , hyeonggon.yoo@sk.com, ying.huang@linux.alibaba.com, honggyu.kim@sk.com, rafael@kernel.org, lenb@kernel.org, gregkh@linuxfoundation.org, rakie.kim@sk.com, dan.j.williams@intel.com, Jonathan.Cameron@huawei.com, dave.jiang@intel.com, horen.chuang@linux.dev, hannes@cmpxchg.org, linux-kernel@vger.org, linux-acpi@vger.kernel.org, linux-mm@kvack.org, kernel-team@meta.com Subject: Re: [PATCH v5] mm/mempolicy: Weighted Interleave Auto-tuning Message-ID: References: <20250207201335.2105488-1-joshua.hahnjy@gmail.com> <20250207182009.7fc099c3074ad00338f25e0a@linux-foundation.org> <20250210163941.15da1e935ed47aacf810fdd0@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250210163941.15da1e935ed47aacf810fdd0@linux-foundation.org> X-Rspamd-Queue-Id: 1F9BB18000D X-Stat-Signature: n6dry9gpnfzgdemcrke39dh1xjkxbrhp X-Rspam-User: X-Rspamd-Server: rspam01 X-HE-Tag: 1739240103-927420 X-HE-Meta: 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 A5BPf0TT ItRk9a8Iwz2QAAD7miCF8zHyHSA2CMNNlyQVC3w5f6q4vdAtUKFD+Zb9ELGmzVjsVrAndwmu+DfLKGiH6WWQAudckDPuj434KD+lvfGamDW56s4JPQh8+zkSrSJLyPDjz3RWOvrZ8uYj7q+2FC0b2WkujMipdNZx4+oxw4GSUtszC4k3vCyZapA8fncny07UP08VeS4uqDXsVdtN7S6v4qIJZJ8Bq4FR6ahHSaLXCw5k9rXiaaNWHxIkOBPKlw5iZMNcqz4roSkeZQzHNFHvHc9ZwT4PxIRJ6YQCbRpM1z5nDCK5uBc1cJZzGaGlIix7WytBm2ZGpxgu6OD1HGOZumdse7YJHpnulq5LEJwdYH3edDlOe2b0v4amuTgXZ/xYlVsstN2uuTicz5GRq1neZh8j2GSPKgLPOYUwNyQ+K7sjyKWAWwwwi34cJEHOYjZbha6Gs/mqMH3KHRPWr+y1/gcrp3+3aU/+kr5MI1FLPPp97ZYE= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000038, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, Feb 10, 2025 at 04:39:41PM -0800, Andrew Morton wrote: > On Mon, 10 Feb 2025 00:36:16 -0500 Gregory Price wrote: > > > On Fri, Feb 07, 2025 at 06:20:09PM -0800, Andrew Morton wrote: > > > On Fri, 7 Feb 2025 12:13:35 -0800 Joshua Hahn wrote: > > > > > > Leading to... how do we know that this patch makes the kernel better? > > > > Just focusing on this question: > > > > The default behavior of weighted interleave without this patch is > > equivalent to normal interleave. This provides a differentiation > > out-of-the box, and that's just a better experience. > > > > We may find the default values / calculations need tweaking in the > > future, but this gives us a good starting point. Anecdotally, I've > > seen an "optimal" distribution of 10:1 based on the numbers run > > sub-optimally compared to 7:1 or 13:1 (but better than default mempol). > > How was this optimality measured/observed? > TL;DR: We used MLC to observe highest sustained bandwidth. Unfortunately I can't post exact numbers at this time. To simplify the results - HMAT reported bandwidth often drifted +/- 10% compared to real observed bandwidth. So the distributions produced by auto-configuration were mildly off - but not by enough to cause performance degredation, we still saw higher sustained bandwidth. When testing the manual configurations I saw that changing from the auto-selected values to a few ticks in one direction or the other resulted in *slightly* better results. Not too surprising. So as long has hardware doesn't lie horrifically, which might be a tall ask, auto config has a good shot at giving a decent default. ~Gregory