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 CFE44EB64DB for ; Tue, 20 Jun 2023 02:19:51 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0EDA78D0002; Mon, 19 Jun 2023 22:19:51 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 09E8D8D0001; Mon, 19 Jun 2023 22:19:51 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E80868D0002; Mon, 19 Jun 2023 22:19:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id D88C38D0001 for ; Mon, 19 Jun 2023 22:19:50 -0400 (EDT) Received: from smtpin20.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 85F26120521 for ; Tue, 20 Jun 2023 02:19:50 +0000 (UTC) X-FDA: 80921520540.20.C6CE523 Received: from mail-qt1-f175.google.com (mail-qt1-f175.google.com [209.85.160.175]) by imf15.hostedemail.com (Postfix) with ESMTP id AF7E5A0005 for ; Tue, 20 Jun 2023 02:19:48 +0000 (UTC) Authentication-Results: imf15.hostedemail.com; dkim=pass header.d=google.com header.s=20221208 header.b=sNHrZ1LK; spf=pass (imf15.hostedemail.com: domain of yuzhao@google.com designates 209.85.160.175 as permitted sender) smtp.mailfrom=yuzhao@google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1687227588; 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=3EPXA9p2JzuvzKzWgCYYXlon3hk90pdnuUAk2cg5+oQ=; b=PZVzRtfC0LhhSiiehg+ACYEa1hlDC+cezpo02woiKONILPoBCGbaPnetvFm2y2owOGo//D oc3fKuOha2tIslyE4q2o6V0NVLXqR3KDzwNpWUJqSZ7VuiCJ1MDw46z4vAOjCpXUNdEUs5 qsegkIi7mY1pNuUJsk1G3ITNq1i+cgY= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1687227588; a=rsa-sha256; cv=none; b=MG8jscaxyrYAS4C7G8iGhBKSZcE8wRIAE4ND8mvmeRLTm/GglPTULtaCRc9MDg/GbqzcVc nBh6N9DOzLtNFPylX6q1DEJ8mbMOYejpa6Da3EwE9lYKKtrccQXN7TLTBLH24dSbRdMan2 NCnD5o1FL3Cir7tFyyNaQlWHvl2tWp0= ARC-Authentication-Results: i=1; imf15.hostedemail.com; dkim=pass header.d=google.com header.s=20221208 header.b=sNHrZ1LK; spf=pass (imf15.hostedemail.com: domain of yuzhao@google.com designates 209.85.160.175 as permitted sender) smtp.mailfrom=yuzhao@google.com; dmarc=pass (policy=reject) header.from=google.com Received: by mail-qt1-f175.google.com with SMTP id d75a77b69052e-3ff242aae7aso242011cf.0 for ; Mon, 19 Jun 2023 19:19:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1687227588; x=1689819588; 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=3EPXA9p2JzuvzKzWgCYYXlon3hk90pdnuUAk2cg5+oQ=; b=sNHrZ1LKYtFz3X1H+MgLDy6o0nbrrhrd1YKD6rtJcW3ttYHs9f5dyY0axzWJCvpzWF 3o0ncsgfP5UDH7NTvRyQAcsGgg9JpLu+jFVAH3FJLnLMFYG+fxywkAC28XwfvqNqZmQK IFUklgGtHIOC3T2HblFwLsGfrEizS/eFOyfR59HJGCj3NLATeWYbP+Pg2p8UrZWBeMpa 32bFBxdll4sSVTWVtOqWKiuT2J6FqgQ2hp7Mod9/Sx0Ak+MTgWCQUN9kS8y1HoT2CBgL iZLyV4YibsmMoTiVxXer72V03w1CLB/TQXGwBB9khGhCUst7GGbzHBkJpPmgooW/jTiW nYCQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687227588; x=1689819588; 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=3EPXA9p2JzuvzKzWgCYYXlon3hk90pdnuUAk2cg5+oQ=; b=cbI+GSbn2QBdvIJLohSqhcjMTKpZkyaWBElAAYw/GQWJh8SOyqAzYiF0dOV2M/PKD2 TUTc9KCONvvd7rEbKT8UOaYCIfgsn0rXdGCwDSmO7yDUM1yxgdR/psTVv+lemRXybd3w CM8f/LQcXQQ0YW/nB0RcVE54IsxR/O4eHnW2qgX0eYtfL5qlWbaSftyvJxGTbPzSBgrn qSVBvVhmk7J0E8NE0yGDVtd+X/yHj89dpkMDxxZ4Mk+xsFZN83FPrjz3jk59zGHUaFJ0 IrJNOQVgf9yd7Kq5gN/IOjJRL6/fCL4eol2Ymg2KgfQVCBwzuML4DBDv9xxwJYYrNpkK Jywg== X-Gm-Message-State: AC+VfDzVkJUrOh7l0RPaQ0v09CDKAJ0ChFNK9/OQ5kJVr887NMFnKC5l cicPV0fCQt9EWIb5cx6RKAKCMJUdU+I9Wzz3+/0A8Q== X-Google-Smtp-Source: ACHHUZ4X3CzpwwHdrmJnCxXIBAk6HQXykSsn31iNLJMOP1aC/6DP8FnJZ+MTQ6AdfTjiGdmwOfd3hduXZamO7zy5qTQ= X-Received: by 2002:ac8:7f93:0:b0:3ef:404a:b291 with SMTP id z19-20020ac87f93000000b003ef404ab291mr104628qtj.7.1687227587619; Mon, 19 Jun 2023 19:19:47 -0700 (PDT) MIME-Version: 1.0 References: <20230526234435.662652-1-yuzhao@google.com> <26cf0b0a-cda5-08a9-a669-6966f9e626b1@redhat.com> In-Reply-To: <26cf0b0a-cda5-08a9-a669-6966f9e626b1@redhat.com> From: Yu Zhao Date: Mon, 19 Jun 2023 20:19:11 -0600 Message-ID: Subject: Re: [PATCH mm-unstable v2 00/10] mm/kvm: locklessly clear the accessed bit To: Paolo Bonzini , Andrew Morton Cc: Alistair Popple , Anup Patel , Ben Gardon , Borislav Petkov , Catalin Marinas , Chao Peng , Christophe Leroy , Dave Hansen , Fabiano Rosas , Gaosheng Cui , Gavin Shan , "H. Peter Anvin" , Ingo Molnar , James Morse , "Jason A. Donenfeld" , Jason Gunthorpe , Jonathan Corbet , Marc Zyngier , Masami Hiramatsu , Michael Ellerman , Michael Larabel , Mike Rapoport , Nicholas Piggin , Oliver Upton , Paul Mackerras , Peter Xu , Sean Christopherson , Steven Rostedt , Suzuki K Poulose , Thomas Gleixner , Thomas Huth , Will Deacon , Zenghui Yu , kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-trace-kernel@vger.kernel.org, x86@kernel.org, linux-mm@google.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: AF7E5A0005 X-Rspam-User: X-Stat-Signature: c41gpjr3w4n7yz55x71xkytksf9zhpys X-Rspamd-Server: rspam03 X-HE-Tag: 1687227588-556704 X-HE-Meta: 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 f02mT9Tg pVtnRQ4289fpgjjRbS5PbRn6a+OKii+SQffKOiRoBTJyA2uZSPEhFxCGmkGcXFMEzcjWruCElJ3ojDZDfof+l8jerWqwcs3Ff0lo+HzGJ8AAS43tVpKSNNEOVS49J5r8vaLiz7XBm/+QoJjNrZ5jlI63N6X2r2XP5I2Qtiu05DLo5s2wa3wL4J3GiLJ++ADJn0bGiMw3PVBkYZFihZzMSp8S5DoUk/If0kmKQtoq3hcUz5YBhSN+p+JRAxeE7SI9hLvnC/plR75lAIdIpQOwSIkFwBUmqTCQ2tRVnO5JvHwob1865XSlfqgxaa7gMI6Zhqi7s8W26+8mmgHSqYeyCL9Vxg3mFT3fA47QdBZY67ACTdv8kBQoy21VG76CbA4xWZX2hTHJCS+bZ1WF8iRLDm8Oxw8u/GG94+CKMatkhpZBtnDUH6wNaYpparHPS1qHwxFGk/tiu2bT0470= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, Jun 9, 2023 at 3:08=E2=80=AFAM Paolo Bonzini = wrote: > > On 5/27/23 01:44, Yu Zhao wrote: > > TLDR > > =3D=3D=3D=3D > > This patchset adds a fast path to clear the accessed bit without > > taking kvm->mmu_lock. It can significantly improve the performance of > > guests when the host is under heavy memory pressure. > > > > ChromeOS has been using a similar approach [1] since mid 2021 and it > > was proven successful on tens of millions devices. > > > > This v2 addressed previous requests [2] on refactoring code, removing > > inaccurate/redundant texts, etc. > > > > [1]https://crrev.com/c/2987928 > > [2]https://lore.kernel.org/r/20230217041230.2417228-1-yuzhao@google.com= / > > From the KVM point of view the patches look good (though I wouldn't > mind if Nicholas took a look at the ppc part). Jason's comment on the > MMU notifier side are promising as well. Can you send v3 with Oliver's > comments addressed? Thanks. I'll address all the comments in v3 and post it asap. Meanwhile, some updates on the recent progress from my side: 1. I've asked some downstream kernels to pick up v2 for testing, the Archlinux Zen kernel did. I don't really expect its enthusiastic testers to find this series relevant to their use cases. But who knows. 2. I've also asked openbenchmarking.org to run their popular highmem benchmark suites with v2. Hopefully they'll have some independent results soon. 3. I've backported v2 to v5.15 and v6.1 and started an A/B experiment involving ~1 million devices, as I mentioned in another email in this thread. I should have some results to share when posting v3.