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=-3.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS 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 1E86DC4332D for ; Thu, 19 Mar 2020 14:03:10 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D2A87208D6 for ; Thu, 19 Mar 2020 14:03:09 +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="El9P5SNt" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D2A87208D6 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=cmpxchg.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 717E36B0005; Thu, 19 Mar 2020 10:03:09 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6EE926B0006; Thu, 19 Mar 2020 10:03:09 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5FEAC6B0007; Thu, 19 Mar 2020 10:03:09 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0131.hostedemail.com [216.40.44.131]) by kanga.kvack.org (Postfix) with ESMTP id 471356B0005 for ; Thu, 19 Mar 2020 10:03:09 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id EDB7F180AD81F for ; Thu, 19 Mar 2020 14:03:08 +0000 (UTC) X-FDA: 76612278456.23.heart55_55a2472a8b23e X-HE-Tag: heart55_55a2472a8b23e X-Filterd-Recvd-Size: 4031 Received: from mail-qt1-f193.google.com (mail-qt1-f193.google.com [209.85.160.193]) by imf26.hostedemail.com (Postfix) with ESMTP for ; Thu, 19 Mar 2020 14:03:08 +0000 (UTC) Received: by mail-qt1-f193.google.com with SMTP id l20so1841921qtp.4 for ; Thu, 19 Mar 2020 07:03:08 -0700 (PDT) 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=zVUeEVeA4E7oLTV0ECgEEG2/YC9N9vz1pl7acrL5ucE=; b=El9P5SNtEcEMu0/AvqR3cV/68A6G4L9fJEmMnnqpaU4OQ0wcTdBipT8Bjk/L5TvYnK /YL4acdcAJuhnKMNx0cl+WEKziQpCPoY3OjDWtb47SHlI7rduYTGncQtgQnMtTmSc3gb bn25hHomNvKLlQomjdaA2ii9mUxMS9BaOqh8BNJaKHhzw9QuFFuoEPXWF0Y/X3plqVc6 X7jn63Dn6pV8Jy3ta1wdTLHyIWH5Qz1KXtVElDpZMM+ljYohZYegpCWNm6tlhJrbyUm3 +uxKb16MMa1Uq/lY4C1lh2IgjjujBMM0uU/o/bA7L7iXRo7UzAaPpvKZB0hLC7dOlQRO bWVQ== 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=zVUeEVeA4E7oLTV0ECgEEG2/YC9N9vz1pl7acrL5ucE=; b=VaZ9qzsSN7siYMGOt0P33yz/Tba5J8VQd9UAF42wBFVC9r+vdAPWnu9OrY1OW5LoBX 4seqaNOfi7onDL9w4Tz6tqHE8mdO6CV/hSVMDeJEOwGXUbYn42F/8acVyV0RRbs09NyH e50ALhW6GaXRHj4srzEUAFODdP6uTb9Wrh6M3pCSEvxllk2+yXbMbQIZdi2cfcAjxwrQ nTHOLlmbejZ6cV4pC08PCsRvWSF0AqljIqf6l7FeelGR2mANhCmm1iWt0LEJYhqyGt1/ G/jq+Z4SwSoxs5plBNpGYaaq4d0w6XqQuv0+XJyXAv+OcqbJAqDX0byJhmf2mWDpNMP0 Qo+Q== X-Gm-Message-State: ANhLgQ1/X790vBLSWyGKCgXyb8ZgBk5Es8FF7FYqxHZm30Xv3o3snw8f r/uIdtOhtKD1/znE6TWG+1eyqQ== X-Google-Smtp-Source: ADFU+vtZKpVbkTQfzQCn4rkumgnjQ034QoO/8wsuuQ9OhmtjDnES5ksSY/f2xcgUYW+S7FTVSDWiHQ== X-Received: by 2002:ac8:6f19:: with SMTP id g25mr3135902qtv.346.1584626586982; Thu, 19 Mar 2020 07:03:06 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::1:a9a9]) by smtp.gmail.com with ESMTPSA id p35sm1611812qtk.2.2020.03.19.07.03.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 19 Mar 2020 07:03:06 -0700 (PDT) Date: Thu, 19 Mar 2020 10:03:05 -0400 From: Johannes Weiner To: Yang Shi Cc: shakeelb@google.com, vbabka@suse.cz, willy@infradead.org, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [v4 PATCH 2/2] mm: swap: use smp_mb__after_atomic() to order LRU bit set Message-ID: <20200319140305.GC187654@cmpxchg.org> References: <1584500541-46817-1-git-send-email-yang.shi@linux.alibaba.com> <1584500541-46817-2-git-send-email-yang.shi@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1584500541-46817-2-git-send-email-yang.shi@linux.alibaba.com> 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 Wed, Mar 18, 2020 at 11:02:21AM +0800, Yang Shi wrote: > Memory barrier is needed after setting LRU bit, but smp_mb() is too > strong. Some architectures, i.e. x86, imply memory barrier with atomic > operations, so replacing it with smp_mb__after_atomic() sounds better, > which is nop on strong ordered machines, and full memory barriers on > others. With this change the vm-scalability cases would perform better > on x86, I saw total 6% improvement with this patch and previous inline > fix. > > The test data (lru-file-readtwice throughput) against v5.6-rc4: > mainline w/ inline fix w/ both (adding this) > 150MB 154MB 159MB > > Fixes: 9c4e6b1a7027 ("mm, mlock, vmscan: no more skipping pagevecs") > Acked-by: Vlastimil Babka > Reviewed-and-Tested-by: Shakeel Butt > Signed-off-by: Yang Shi Acked-by: Johannes Weiner