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=-6.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 AC733C00A89 for ; Mon, 2 Nov 2020 20:46:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 650D02071A for ; Mon, 2 Nov 2020 20:46:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=cmpxchg-org.20150623.gappssmtp.com header.i=@cmpxchg-org.20150623.gappssmtp.com header.b="GkYdoJDP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727167AbgKBUqR (ORCPT ); Mon, 2 Nov 2020 15:46:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51702 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726881AbgKBUqC (ORCPT ); Mon, 2 Nov 2020 15:46:02 -0500 Received: from mail-qt1-x844.google.com (mail-qt1-x844.google.com [IPv6:2607:f8b0:4864:20::844]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4EFEBC0617A6 for ; Mon, 2 Nov 2020 12:46:00 -0800 (PST) Received: by mail-qt1-x844.google.com with SMTP id h12so10159887qtc.9 for ; Mon, 02 Nov 2020 12:46:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=gB2e508EdlwqwocPMg7gSFq3mG+QyX2QZ372rPOjJ/0=; b=GkYdoJDP3SQawBGQzX6f6vlVSfuqoKuZi6YHT2czkvxud7XGR/gxb7pT8E9JRX0BM7 AvNke3kr4copQpUNeKato3NWktKZn1lTJDOtigAcUl2jZbZ9bjT/vOoyEMuOLG1qDpg8 GOM7xz+0GZBVO+TPEwNSNzSbvcfbflDoxFA4zLtKuH3uO3oqHajPdTEAVlB9bHCruMNX fW4rf3TPJJhY2i/p0WdoPnGZRHioMKc53ApqR1SLSSKZHh4ZR76W9xVQ7P9PiCjF1iFw S+fOHmuwKkLPOZ9wtu80sukk1jYcLnFOjCAIj8TxGvfQlIb/LfI7K0YOmmFMR6D97BOw 7iJQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=gB2e508EdlwqwocPMg7gSFq3mG+QyX2QZ372rPOjJ/0=; b=gQX1X8zbWbZbHds8VTgNWT33neypeTqdlYM79Ol9zcrr7it2MZQLo8FU4fogxMPCw5 R1vRe5P7us0JI8cBqnBlqjwPkHpVjTYTmdFaS2Wbw+SpTuTm9DXg7sNL707OD3eKnldY LsgEf9e+nEUtoxX9W6/mEScPjgmgnEEFGnBDeMFmmRTI6wlGM3yvNdLBNKcrFpzYAkzm agd68GE/QpqEypRFyIGdOOj2FQXvCmHWuhomh70nCEweefd7ByG05hed9sxJAZxtQEbb 23NDAD8s4mBvQcjfM/711HhERBEIuZmlSq3Fud5c2Fpn9dR5wP/Y54lTLZvVJQ2cYHfW EXqw== X-Gm-Message-State: AOAM5310ppSNiQ7UXM/jPw2SuyJsFaw9ryRAJeVrhkCC5dQX9xiAXjBz dLGz+asOVY7Q9qIjO4tLoAK6Ow== X-Google-Smtp-Source: ABdhPJxudlJHRrYzOFWNo8jeGkzWZZdZucQ6P+YEDzHlTPpQ1eFVaOSr7/XsAs+QhppEnZoVEhob5g== X-Received: by 2002:ac8:6045:: with SMTP id k5mr15221157qtm.216.1604349959591; Mon, 02 Nov 2020 12:45:59 -0800 (PST) Received: from localhost ([2620:10d:c091:480::1:2f6e]) by smtp.gmail.com with ESMTPSA id 67sm8636195qkd.14.2020.11.02.12.45.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Nov 2020 12:45:58 -0800 (PST) Date: Mon, 2 Nov 2020 15:44:13 -0500 From: Johannes Weiner To: Alex Shi Cc: akpm@linux-foundation.org, mgorman@techsingularity.net, tj@kernel.org, hughd@google.com, khlebnikov@yandex-team.ru, daniel.m.jordan@oracle.com, willy@infradead.org, lkp@intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, shakeelb@google.com, iamjoonsoo.kim@lge.com, richard.weiyang@gmail.com, kirill@shutemov.name, alexander.duyck@gmail.com, rong.a.chen@intel.com, mhocko@suse.com, vdavydov.dev@gmail.com, shy828301@gmail.com, Alexander Duyck , Thomas Gleixner , Andrey Ryabinin Subject: Re: [PATCH v20 19/20] mm/lru: introduce the relock_page_lruvec function Message-ID: <20201102204413.GC740958@cmpxchg.org> References: <1603968305-8026-1-git-send-email-alex.shi@linux.alibaba.com> <1603968305-8026-20-git-send-email-alex.shi@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1603968305-8026-20-git-send-email-alex.shi@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 29, 2020 at 06:45:04PM +0800, Alex Shi wrote: > From: Alexander Duyck > > Use this new function to replace repeated same code, no func change. > > When testing for relock we can avoid the need for RCU locking if we simply > compare the page pgdat and memcg pointers versus those that the lruvec is > holding. By doing this we can avoid the extra pointer walks and accesses of > the memory cgroup. > > In addition we can avoid the checks entirely if lruvec is currently NULL. > > Signed-off-by: Alexander Duyck > Signed-off-by: Alex Shi > Acked-by: Hugh Dickins > Cc: Johannes Weiner > Cc: Andrew Morton > Cc: Thomas Gleixner > Cc: Andrey Ryabinin > Cc: Matthew Wilcox > Cc: Mel Gorman > Cc: Konstantin Khlebnikov > Cc: Hugh Dickins > Cc: Tejun Heo > Cc: linux-kernel@vger.kernel.org > Cc: cgroups@vger.kernel.org > Cc: linux-mm@kvack.org Acked-by: Johannes Weiner