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 84CBDC3DA7F for ; Mon, 5 Aug 2024 01:59:14 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id DFCE86B007B; Sun, 4 Aug 2024 21:59:13 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DAC946B0082; Sun, 4 Aug 2024 21:59:13 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C73F96B0085; Sun, 4 Aug 2024 21:59:13 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id AA6DD6B007B for ; Sun, 4 Aug 2024 21:59:13 -0400 (EDT) Received: from smtpin20.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 2CF5E1A1BA4 for ; Mon, 5 Aug 2024 01:59:13 +0000 (UTC) X-FDA: 82416534186.20.0FFCAB8 Received: from mail-qk1-f177.google.com (mail-qk1-f177.google.com [209.85.222.177]) by imf17.hostedemail.com (Postfix) with ESMTP id 6805E40006 for ; Mon, 5 Aug 2024 01:59:11 +0000 (UTC) Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b="cHqvQ//L"; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf17.hostedemail.com: domain of laoar.shao@gmail.com designates 209.85.222.177 as permitted sender) smtp.mailfrom=laoar.shao@gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1722823083; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=H2VCiYqZdCHLs2zk48/qevHWK8/IJvEuxKvDU81eFXc=; b=zmNcXgMi+7bSPM4ZslF1/uQVEn3ADgndQWjyqKZvPWIIdb494ZNvrzGcZpCI4PoGYY420K B/cdLis+CqUmGqGLb1bST0UHiOBREMjltBLnJTgBmC2kEixXP/LS81tArIG9l/pCLUvA2o EPBiKLgivwTJYB0Izk8eTFNYeGl7nAw= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1722823083; a=rsa-sha256; cv=none; b=jzBcfrzJy0yYk7tJuE9FukPUVv+Pdy4etMdNaedOFi8hQkWYXePZb06sB4Mog2iYPTEIh1 7aa5hLbXtQyxbeTEuKXuJNnzLNfvILr96K3GzP8PPbWz2EHHV6hLoOwr60X4NKJi66Z6j3 VNuNHNTUxVyrtRhuTtrzNWcNoUGi0cU= ARC-Authentication-Results: i=1; imf17.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b="cHqvQ//L"; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf17.hostedemail.com: domain of laoar.shao@gmail.com designates 209.85.222.177 as permitted sender) smtp.mailfrom=laoar.shao@gmail.com Received: by mail-qk1-f177.google.com with SMTP id af79cd13be357-7a1d3874c1eso575717385a.2 for ; Sun, 04 Aug 2024 18:59:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1722823150; x=1723427950; darn=kvack.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=H2VCiYqZdCHLs2zk48/qevHWK8/IJvEuxKvDU81eFXc=; b=cHqvQ//LDAiWPScdgLoVoa1ZiCvithivKPaK7913Guw6qmU4LjEB0BtTNgjrSXhzPC sXXkMPsrgEqla2bRVEuQYFOzJ+Bz/pdrrkVVvL1QkOHyQyztIZ25oTaEG17p9tFVuK/h BJKg6nDoTRhInQPcbdFECvLUAvwq0qjP/LjSUL2JyRr5qihSQnm9sxG4WP/U57TEK5i5 dX8tvP/LvUsNa4yCOgC3kgmJCQMqBuJEoVlbco53dcBm+EagfoKsTi+11Zh8zi5YfkQr N9SbbDUhDaARu58dxInUS94hsaRyGUAUs6LK1FABCuZUzZxA3gEHBAHvWHhCHcEPVC4N vGOw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1722823150; x=1723427950; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=H2VCiYqZdCHLs2zk48/qevHWK8/IJvEuxKvDU81eFXc=; b=TNW6xidNyAl1FBki8YHaVkGaR7e63jxd43h9Ha0rrjjIEfaZwHhxXk4LlluKUyVJyw 1Y/Or2Y8C5BrAUCU/i19i6tbapygwpFVnX2aGs0FyBMRAKuSF2XkcHPLOfyZ6Bp4hqhB NXeZSkoC+WtII9tEj0cnnriDotTmbYi7SKNdLYXdg760/xgvVQTUWnTm4Vj3CRHTq6dM 1E9gPWltcRkgBFgAediR0YQaHiIFiCXfx7s1RkvpT/8pP4ghRs7ApzfyDSMPnBslAU/C XFXTCIlLmYp1LBezPlxXXz3Vy1dx/fOnSnaE1HYyDZ5Tv3mL1qb9MMMpcpuhCsPbZ9xM Y2zQ== X-Forwarded-Encrypted: i=1; AJvYcCU5wKIi4Qw6h8vG5AqHzfEkeyuuW7qurFU5oS9jkodn2HBIbklniccsfwignWM48EV09BngEBnof05o8EKcJhvtJqw= X-Gm-Message-State: AOJu0Yw0HBvFjmSTtaDeBM+jHM8T4myJICB6IrcO20QFKwXOww02zhMl xstcFgeBVesDESuARLgNoiMqpRxzhvWybai0qD5YoQO659hRFeFqRBNor0DzQsLfKO9Ywp3gSyu Gb/etnnUtFjU2EVLhT4TEczZ9tr4= X-Google-Smtp-Source: AGHT+IE+bnANV//Yi0qMRakpQ9uXz9qzDQCZLcjAt40/1BoDbkXIaqywBYJMc6iCiQGaTUP1pHrAvEXqYqVRbf+7NWM= X-Received: by 2002:a05:6214:3115:b0:6b5:da50:ac28 with SMTP id 6a1803df08f44-6bb98476decmr99875476d6.38.1722823150334; Sun, 04 Aug 2024 18:59:10 -0700 (PDT) MIME-Version: 1.0 References: <20240804080107.21094-1-laoar.shao@gmail.com> <20240804080107.21094-4-laoar.shao@gmail.com> <87r0b3g35e.fsf@yhuang6-desk2.ccr.corp.intel.com> In-Reply-To: <87r0b3g35e.fsf@yhuang6-desk2.ccr.corp.intel.com> From: Yafang Shao Date: Mon, 5 Aug 2024 09:58:33 +0800 Message-ID: Subject: Re: [PATCH v3 3/3] mm/page_alloc: Introduce a new sysctl knob vm.pcp_batch_scale_max To: "Huang, Ying" Cc: akpm@linux-foundation.org, mgorman@techsingularity.net, linux-mm@kvack.org, Matthew Wilcox , David Rientjes Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 6805E40006 X-Stat-Signature: nk1ho1kefrax6z14q31wc4bfqn4z18a3 X-Rspam-User: X-HE-Tag: 1722823151-148818 X-HE-Meta: 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 xU/0P8QM tf20XBbeJd8VbcAWb8znV2h0wS4ZQc/0I8v4doocJbiE+A5dJ99TTwxPH7jnQ5u3VgUqg2Ecr+egt4qtGxZxd/Be88PHnejtrYKiv/lrNi4u8ivGJE8WaBVkd/8ZLAgBVpyfcalSiLwm7Bhwr4Zw2ENDgNdr3LBQF5/JPfrKStuyo3jzL6XFOARLDY9E3Dzhk0yOY3IAwAgYxNpGeXyhLgwmJ6VuZxItEE1GVVmWYPG5clDRA7xcLvZsqxtT8EANQLU02qRKVb3mP4HKtF+MxFkmw3Iv5rIa9Y7kTSW7VI9PjKUCKrHMs4fZvksuNkVeZMXHGQtDjijow7OJPoGJftyxGrjjFBFu9vPDZXf5eO1S/Nw9UmiaunPc6hIiIf8HO+HsP6OyKBTXU/OSjOitAgaExA3JPjY/8slNb X-Bogosity: Ham, tests=bogofilter, spamicity=0.000077, 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, Aug 5, 2024 at 9:41=E2=80=AFAM Huang, Ying w= rote: > > Yafang Shao writes: > > [snip] > > > > > Why introduce a systl knob? > > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D > > > > From the above data, it's clear that different CPU types have varying > > allocation latencies concerning zone->lock contention. Typically, peopl= e > > don't release individual kernel packages for each type of x86_64 CPU. > > > > Furthermore, for latency-insensitive applications, we can keep the defa= ult > > setting for better throughput. > > Do you have any data to prove that the default setting is better for > throughput? If so, that will be a strong support for your patch. No, I don't. The primary reason we can't change the default value from 5 to 0 across our fleet of servers is that you initially set it to 5. The sysadmins believe you had a strong reason for setting it to 5 by default; otherwise, it would be considered careless for the upstream kernel. I also believe you must have had a solid justification for setting the default value to 5; otherwise, why would you have submitted your patches? > > > In our production environment, we set this > > value to 0 for applications running on Kubernetes servers while keeping= it > > at the default value of 5 for other applications like big data. It's no= t > > common to release individual kernel packages for each application. > > > > [snip] > > -- > Best Regards, > Huang, Ying -- Regards Yafang