From patchwork Tue Mar 28 22:16:44 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yosry Ahmed X-Patchwork-Id: 13191632 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 B79B1C77B6C for ; Tue, 28 Mar 2023 22:17:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230255AbjC1WRy (ORCPT ); Tue, 28 Mar 2023 18:17:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39074 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230208AbjC1WRT (ORCPT ); Tue, 28 Mar 2023 18:17:19 -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 3CEF53A9E for ; Tue, 28 Mar 2023 15:17:08 -0700 (PDT) Received: by mail-pf1-x44a.google.com with SMTP id l19-20020a056a0016d300b006257255adb4so6405661pfc.13 for ; Tue, 28 Mar 2023 15:17:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; t=1680041827; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=3EqK7sQZOfVTLBQ7dVPZO4hRmfVfAzm1laH3BYvfeCs=; b=Jh0ANfJdLtvcj14Ycx8o0NJ4r9qhZa68Pa0uc2IX0QIjCZKetrfT/Nq/ZDVr5AllWU XClT4UcNh1sPOxMcsh6sWOQo9/2lETExd/HKLVBB2M4wtgPvzRmNcVBtdBrQWB7ALdhZ R5a35ECD7K8gif2eOzvhZ1FDX+1AdzcBxQSZ/AU6EUVqL3HECb2nu5rbm6oZEkaJmqE+ JiSGi5TQPR/5oszlj+b2yUkvaRVAqFo8Ka4HGQ6Ui7wSkXSWPGkTPTug5dc09uPeC/es /a05azr2/gL04QjqP7TTdBynMB9W71leZpwkNhiYtT2r27tRHGjbrwcjlQFLDRhwcOoU qhHA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680041827; 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=3EqK7sQZOfVTLBQ7dVPZO4hRmfVfAzm1laH3BYvfeCs=; b=2OXECpP6mMZkyL6az8pnIKAIjmwzS7jAA00GrKAb48fZcczC0joTt5kzo+ISYJGexp OfmiiQcC4H521y4bBEIvw/lT1erRKbqrg9JO+ysFeqY8OVowR7Oaep5QCaP2PgwfYF1t vLvyJPGIwricSWKgj/WG8lWqFnHOL48qLFGDcmIf3uWGzLXkDS8iBiY3DlFDMuAf1paw wJGCehdYm68GPzy/POYK4/SDkOVjRkrDnBufSOcIOg502HTypsbHXOPnhRZuTOedaVco +yFyehZ7/9MdWvIS7w3ZoTuWyUWT6uh6pMjW7GO2Ix3ckPpGvAPCL9z9bb1L1543GyYN wAyQ== X-Gm-Message-State: AAQBX9c1ZEoRv6RajmJQZ0vPudRFM40lePBtBNf2zJR29/zdxgacRC6J 7UB8nb8edKxRVLFYnwuY8qTAPXmsMzz85NZm X-Google-Smtp-Source: AKy350b8EHObFwTAz134ielB7Lfw4iTDwRchFeXjbgsPVENWxNL5SgSGxt3wM+3XFB7OgKxVRznr5DrlZ29gVq8P X-Received: from yosry.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:2327]) (user=yosryahmed job=sendgmr) by 2002:a17:90a:fb57:b0:23d:30c2:c5b7 with SMTP id iq23-20020a17090afb5700b0023d30c2c5b7mr60436pjb.3.1680041826556; Tue, 28 Mar 2023 15:17:06 -0700 (PDT) Date: Tue, 28 Mar 2023 22:16:44 +0000 In-Reply-To: <20230328221644.803272-1-yosryahmed@google.com> Mime-Version: 1.0 References: <20230328221644.803272-1-yosryahmed@google.com> X-Mailer: git-send-email 2.40.0.348.gf938b09366-goog Message-ID: <20230328221644.803272-10-yosryahmed@google.com> Subject: [PATCH v2 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: linux-block@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 Acked-by: Michal Hocko --- mm/memcontrol.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 361c0bbf7283..a63ee2efa780 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));