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=-8.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=ham 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 B8C4FC433E6 for ; Wed, 10 Feb 2021 01:13:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 88DA564E32 for ; Wed, 10 Feb 2021 01:13:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234792AbhBJBMw (ORCPT ); Tue, 9 Feb 2021 20:12:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59060 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234389AbhBIWYy (ORCPT ); Tue, 9 Feb 2021 17:24:54 -0500 Received: from mail-qk1-x730.google.com (mail-qk1-x730.google.com [IPv6:2607:f8b0:4864:20::730]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 90132C0698D7 for ; Tue, 9 Feb 2021 14:22:10 -0800 (PST) Received: by mail-qk1-x730.google.com with SMTP id v206so8109404qkb.3 for ; Tue, 09 Feb 2021 14:22:10 -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=YqilSyANb2yKNyp5C84XuLtT56SS42oSdtYgcD/KNKI=; b=rkk64bC3gUH20iyUq9lXg4/whibac5PNI6g9rBOp/8JLjQAVtEYBgWUgOCQhrhwtc1 nAYoOFQubJbwTa+qzQi04ksycVdMK7LMFKIuj/KfCuI09ixolgbSeqL+kbpbbHgFCIMN LgoivRNKmLXSTnErsEeVwHAEirhpvARnUmcLCfE1DgMyssikk94rhdpjgupMncATxIuo E5f8h5UaTQrw68w6sBS1VAunb/YpnJt4rznlF++DYpFiflpSboc8me+f7BlJn5SsFzLj zC20W6+7uQ9DJ+W7ujnSd8tfu/irV2V6J2IjSaoLbFjMDUjbuXO1ncNnouv3F8M4H50i CxUQ== 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=YqilSyANb2yKNyp5C84XuLtT56SS42oSdtYgcD/KNKI=; b=eA/+bpzLANarRFz0QQv4BQ/G5wpApV75XK5dGhSvcDWwSJ/yXabZtpAAfWVBkjpIjy aBPDxewRuMdFJPtgG/2KOvSkV8iQAVpM60IRW6u2u9Sb+7JuCJVob/wLOI5YQWOwmzTc Tkp5aOHNak/UIq9iLw1tOsugdvycRqVRGi+/JHMUNGhJOhQo2JMLj/g9Q9qMxCty3fIQ 2YyEGeTnipqrk2lro7Teu4wL3vg2CjrNpba8BFUFdefXsRWtY1bIX+8OXoDqWSRxtjFq 11E1CDJ2MftWNDNPamWMky8S3BKFf1FxeVujifKCvbzvCEjRfkVL7MYkh4Mz9ZHzdUWx Ajpg== X-Gm-Message-State: AOAM532RprZGVkDVc+aCzFDspl3km0qxlTCip+ErA56J46nLkC+5okwg snxbzzhaMJAPuEvA3LSZR6Rbsi0VCLW3UQ== X-Google-Smtp-Source: ABdhPJz4Zr6dJzukGC3DYAKKOMDeZ70xNoCDbVRx+hX2r3XTqUWEDeBvBquPHQaBI4BhKc9KU0ZbMw== X-Received: by 2002:a05:620a:2239:: with SMTP id n25mr412298qkh.46.1612909329847; Tue, 09 Feb 2021 14:22:09 -0800 (PST) Received: from localhost (70.44.39.90.res-cmts.bus.ptd.net. [70.44.39.90]) by smtp.gmail.com with ESMTPSA id t8sm48886qkt.125.2021.02.09.14.22.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 09 Feb 2021 14:22:09 -0800 (PST) Date: Tue, 9 Feb 2021 17:22:08 -0500 From: Johannes Weiner To: Tim Chen Cc: Andrew Morton , Michal Hocko , Vladimir Davydov , Dave Hansen , Ying Huang , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/3] mm: Fix missing mem cgroup soft limit tree updates Message-ID: References: <3b6e4e9aa8b3ee1466269baf23ed82d90a8f791c.1612902157.git.tim.c.chen@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3b6e4e9aa8b3ee1466269baf23ed82d90a8f791c.1612902157.git.tim.c.chen@linux.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Tim, On Tue, Feb 09, 2021 at 12:29:47PM -0800, Tim Chen wrote: > @@ -6849,7 +6850,9 @@ static void uncharge_page(struct page *page, struct uncharge_gather *ug) > * exclusive access to the page. > */ > > - if (ug->memcg != page_memcg(page)) { > + if (ug->memcg != page_memcg(page) || > + /* uncharge batch update soft limit tree on a node basis */ > + (ug->dummy_page && ug->nid != page_to_nid(page))) { The fix makes sense to me. However, unconditionally breaking up the batch by node can unnecessarily regress workloads in cgroups that do not have a soft limit configured, and cgroup2 which doesn't have soft limits at all. Consider an interleaving allocation policy for example. Can you please further gate on memcg->soft_limit != PAGE_COUNTER_MAX, or at least on !cgroup_subsys_on_dfl(memory_cgrp_subsys)? Thanks