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 5FD34C433EF for ; Sat, 12 Mar 2022 23:26:26 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 662B08D0002; Sat, 12 Mar 2022 18:26:25 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 612878D0001; Sat, 12 Mar 2022 18:26:25 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4B4648D0002; Sat, 12 Mar 2022 18:26:25 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0110.hostedemail.com [216.40.44.110]) by kanga.kvack.org (Postfix) with ESMTP id 395B68D0001 for ; Sat, 12 Mar 2022 18:26:25 -0500 (EST) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id D7543181F5FFE for ; Sat, 12 Mar 2022 23:26:24 +0000 (UTC) X-FDA: 79237320288.20.0132CEF Received: from mail-yb1-f170.google.com (mail-yb1-f170.google.com [209.85.219.170]) by imf23.hostedemail.com (Postfix) with ESMTP id 715EF140012 for ; Sat, 12 Mar 2022 23:26:24 +0000 (UTC) Received: by mail-yb1-f170.google.com with SMTP id g26so23963569ybj.10 for ; Sat, 12 Mar 2022 15:26:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=vNx6s5KnOqjV7Tmfqf+dCQj5955OsQk4Bwz0LXPX7LA=; b=X+xmHlE/1nenrdIB0uJ20KSXJHeWvXUvb1BpZ9ptuVQi9xqy7+oPZ1c2bf4VTZTKkU qaWDXjdiFt94igAFkJ0X6u+UCtjZWhugqb5Xocox2E4xSKDhBnPsoXnzrWeas6Uqf8F5 J9WnD5oCn0Z3njgyeWWbg4R5caMpl4YZ/5NjTPP/Y8yM6J26ibFA5Kje9u7bEsRwvG7T /dNh2fJN47sVp490RzgLd/D9jjXA72ihDoW/Ashok+4sjLm0dndW43IkSghIgeQX2fDX SL8N/DIBu9sC7mVXmgSZ024yIh2VzYM8B7b7FL2glw51PY9M8Pn6BF52CRzkTwu2y2H5 bFug== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=vNx6s5KnOqjV7Tmfqf+dCQj5955OsQk4Bwz0LXPX7LA=; b=PZNP7QQr3GJLvGvhN1HzIyh2Fxz1unTY5NOa2LZ/b2mA+7fyT2gjPpIJvLCtZtTnsf 0Tn5WR+c2YFz+FQQU9fFQCxobSWq84ucg4NRgbU/Rf+EJZHD66+sXk7THGk3QyLAICEF KUeFXh4dMM3nnU/6rR7qKjBTyB2CYNi2/AHhYBgd9Vy5u0PgUTBAMudhjlDWk3hexn7j +JKhSvC7ooaR3v4QNT/o+ZrG2DhBc48nuFnYb/qWY51Gm0hdhFJGKeUgrT9SayhSOFOf hQrQrtxDRvdXdi//93EjcH2dKA3FEyEaXrNLbGzxeRYVGdKYvySVUbeikMZDVdfnORJj QeSg== X-Gm-Message-State: AOAM533BfOtp8pjZDTHVRRULIyefiyef5IZO/kJwbCLcRWeyRLoo2Zn1 7p5LuchsPmgnP+o/mfUfAT8SuVBrwvmb5LSv3ManmA== X-Google-Smtp-Source: ABdhPJzeMXGyyZv4j+lG96D740YNvnKxeU/9Wh8dXoGzwHH0Cd99LEMJVacYfGqtsAOoTBDb8Tk5G71QcqCmZygRGSc= X-Received: by 2002:a25:d9c7:0:b0:628:be42:b671 with SMTP id q190-20020a25d9c7000000b00628be42b671mr12905465ybg.387.1647127583323; Sat, 12 Mar 2022 15:26:23 -0800 (PST) MIME-Version: 1.0 References: <20220312154321.GC1189@xsang-OptiPlex-9020> <15307f8a-c202-75d8-1361-dae0146df734@suse.cz> In-Reply-To: <15307f8a-c202-75d8-1361-dae0146df734@suse.cz> From: Eric Dumazet Date: Sat, 12 Mar 2022 15:26:12 -0800 Message-ID: Subject: Re: [mm/page_alloc] 8212a964ee: vm-scalability.throughput 30.5% improvement To: Vlastimil Babka Cc: kernel test robot , Mel Gorman , 0day robot , Michal Hocko , Shakeel Butt , Wei Xu , Greg Thelen , Hugh Dickins , David Rientjes , LKML , lkp@lists.01.org, "Huang, Ying" , "Tang, Feng" , zhengjun.xing@linux.intel.com, fengwei.yin@intel.com, Eric Dumazet , Andrew Morton , linux-mm Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 715EF140012 X-Stat-Signature: 35t13kc4k4zhrgtp3yhooyajkgcjwoow X-Rspam-User: Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b="X+xmHlE/"; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf23.hostedemail.com: domain of edumazet@google.com designates 209.85.219.170 as permitted sender) smtp.mailfrom=edumazet@google.com X-Rspamd-Server: rspam02 X-HE-Tag: 1647127584-922636 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 Sat, Mar 12, 2022 at 10:59 AM Vlastimil Babka wrote: > > On 3/12/22 16:43, kernel test robot wrote: > > > > > > Greeting, > > > > FYI, we noticed a 30.5% improvement of vm-scalability.throughput due to commit: > > > > > > commit: 8212a964ee020471104e34dce7029dec33c218a9 ("Re: [PATCH v2] mm/page_alloc: call check_new_pages() while zone spinlock is not held") > > url: https://github.com/0day-ci/linux/commits/Mel-Gorman/Re-PATCH-v2-mm-page_alloc-call-check_new_pages-while-zone-spinlock-is-not-held/20220309-203504 > > patch link: https://lore.kernel.org/lkml/20220309123245.GI15701@techsingularity.net > > Heh, that's weird. I would expect some improvement from Eric's patch, > but this seems to be actually about Mel's "mm/page_alloc: check > high-order pages for corruption during PCP operations" applied directly > on 5.17-rc7 per the github url above. This was rather expected to make > performance worse if anything, so maybe the improvement is due to some > unexpected side-effect of different inlining decisions or cache alignment... > I doubt this has anything to do with inlining or cache alignment. I am not familiar with the benchmark, but its name (anon-w-rand-hugetlb) hints at hugetlb ? After Mel fix, we go over 512 'struct page' to perform sanity checks, thus loading into cpu caches the 512 cache lines. This caching is done while no lock is held. If after this huge page allocation some mm operation needs to access these 512 struct pages, while holding a lock, then sure, there is a huge gain.