From patchwork Tue Mar 28 06:16:38 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yosry Ahmed X-Patchwork-Id: 13190552 X-Patchwork-Delegate: kuba@kernel.org 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BED13C77B61 for ; Tue, 28 Mar 2023 06:18:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232752AbjC1GSB (ORCPT ); Tue, 28 Mar 2023 02:18:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34896 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232642AbjC1GRj (ORCPT ); Tue, 28 Mar 2023 02:17:39 -0400 Received: from mail-pf1-x44a.google.com (mail-pf1-x44a.google.com [IPv6:2607:f8b0:4864:20::44a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 766593595 for ; Mon, 27 Mar 2023 23:16:59 -0700 (PDT) Received: by mail-pf1-x44a.google.com with SMTP id w135-20020a62828d000000b0062c4eb40ddeso3879511pfd.3 for ; Mon, 27 Mar 2023 23:16:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; t=1679984218; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=Vy8wz9BoJKucmcMBXvIGPOuITeThi///HtllaZbgtCo=; b=G3C3U8FV5xO4vsplclhU9+4PkBH686vIIIrQFFquICu8//oGn5xL/Tmt4VNVE1HnMt hORJK4mB81itHhGs1+plTWPpHn6PXb4UvAXp2In5M38sRtIYXUydb86gW9UCcwU8NUMK AKSJULzbSmJ/Zh8xR8z20CA4EuuFhupmK6yUb7XM0dWX+orGZyC4roBLz+bFSVl/SrGz jDFcau8INkey+e5jkuXnym7vXagjhy1slym0NeO+iUEtBeJGIjBlnt29eYQhaZCdCsb9 TItPIolnMlslNIl39r9v4yrb91hLywelng+1GUeMlXmGbk+u0V1YHrp34uG87/cMCuf4 DKLw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1679984218; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Vy8wz9BoJKucmcMBXvIGPOuITeThi///HtllaZbgtCo=; b=hiJuO2NgiQWcOxgQTCfzE8zc2zU0Frr8a0Xmg58I/SvPegjntQW+gcc8ehdNBNrqFz q/5K9VC94Zud70WrD1PJQBI8YmVTnDQ4m1RTbvYyl4StaTUa4jq5BR5MG2D+es3xzgms nIIECBHZvV+iFZQQgXOIHwbScRClGLleKmSWUei74PskyAIAbvchB1BFHOjiSVqBmEYK b28eRHLdz4tSZlREO+3i0MRAHAJSu4N1J0UpUqgayqJFaHSrB7UL4EZCcdlBEeWVa632 Xyje09sejRiThigPl7W7rczhZ5MBFucTDoyNi1x1gz3RI6iSUBBP2+7KQ78sP+AaWXce 8ifw== X-Gm-Message-State: AAQBX9eMpQdl6WuBQnc3/ve/1tVQ/tdFzDjNJtlvgzEk5B6wIYFXV22U cu6QZjag5d/CZlNiwe/2wgNM0e8ePzRr4XgS X-Google-Smtp-Source: AKy350aVn7i51pwbUpBHdDCfopSzB0y7+YNrEoZI1+8jV5mnjDSATrQRcelVSU3ikfIyno7DP54WO5q/0DmrmRgv X-Received: from yosry.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:2327]) (user=yosryahmed job=sendgmr) by 2002:a05:6a00:1781:b0:593:fcfb:208b with SMTP id s1-20020a056a00178100b00593fcfb208bmr7364360pfg.3.1679984218020; Mon, 27 Mar 2023 23:16:58 -0700 (PDT) Date: Tue, 28 Mar 2023 06:16:38 +0000 In-Reply-To: <20230328061638.203420-1-yosryahmed@google.com> Mime-Version: 1.0 References: <20230328061638.203420-1-yosryahmed@google.com> X-Mailer: git-send-email 2.40.0.348.gf938b09366-goog Message-ID: <20230328061638.203420-10-yosryahmed@google.com> Subject: [PATCH v1 9/9] memcg: do not modify rstat tree for zero updates From: Yosry Ahmed To: Tejun Heo , Josef Bacik , Jens Axboe , Zefan Li , Johannes Weiner , Michal Hocko , Roman Gushchin , Shakeel Butt , Muchun Song , Andrew Morton , " =?utf-8?q?Michal_Koutn=C3=BD?= " Cc: Vasily Averin , cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, bpf@vger.kernel.org, Yosry Ahmed Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org In some situations, we may end up calling memcg_rstat_updated() with a value of 0, which means the stat was not actually updated. An example is if we fail to reclaim any pages in shrink_folio_list(). Do not add the cgroup to the rstat updated tree in this case, to avoid unnecessarily flushing it. Signed-off-by: Yosry Ahmed Acked-by: Shakeel Butt Acked-by: Johannes Weiner --- mm/memcontrol.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 0c0e74188e90..828e670e721a 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -618,6 +618,9 @@ static inline void memcg_rstat_updated(struct mem_cgroup *memcg, int val) { unsigned int x; + if (!val) + return; + cgroup_rstat_updated(memcg->css.cgroup, smp_processor_id()); x = __this_cpu_add_return(stats_updates, abs(val));