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=-9.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 762FEC433E0 for ; Tue, 16 Mar 2021 00:52:32 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id ECFD464F6E for ; Tue, 16 Mar 2021 00:52:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ECFD464F6E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 5AF466B006C; Mon, 15 Mar 2021 20:52:31 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 55F9D6B006E; Mon, 15 Mar 2021 20:52:31 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3FDF36B0070; Mon, 15 Mar 2021 20:52:31 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0043.hostedemail.com [216.40.44.43]) by kanga.kvack.org (Postfix) with ESMTP id 2433C6B006C for ; Mon, 15 Mar 2021 20:52:31 -0400 (EDT) Received: from smtpin14.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id D2A17180AD830 for ; Tue, 16 Mar 2021 00:52:30 +0000 (UTC) X-FDA: 77923911660.14.1A4AAFE Received: from mail-pg1-f181.google.com (mail-pg1-f181.google.com [209.85.215.181]) by imf18.hostedemail.com (Postfix) with ESMTP id 78DF22000383 for ; Tue, 16 Mar 2021 00:52:30 +0000 (UTC) Received: by mail-pg1-f181.google.com with SMTP id p21so21492961pgl.12 for ; Mon, 15 Mar 2021 17:52:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=xZoZuWb2tBzrGLpbmU0QlJ3nLJM79Q95ZotWRYdo/dU=; b=udPVwzShPfqLnJku3Fi+dpSMekaBCR/1LK2aWf1PcUDLZZrudJibDmi0qfrv/bqFQi 2H93ctwVoCfgOr2SN8hWgsDeHQvcBvP8XiGlBtPsy1YjVOKrLNSDioU8RZp8zwqXc3A6 oJI2UWvwmwVvKThzHVEDxhD1X5nOp/VOJj4PbXs+hR49oilZocWDgVy25YKK8EOHXYdm qYcsl+P22j8n75mkw0RH4x+LoJ8q9WWI19/8ttIpLAb5Tp5h50c6BXldIRsMApX7ghT4 eTArYFObAgWoCrP6O+yFbQ/MxkIiKeK6kzPC9Og6q+TOirm7W6j9lHvVgDGzbYPmZY3q 8c5Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=xZoZuWb2tBzrGLpbmU0QlJ3nLJM79Q95ZotWRYdo/dU=; b=Q+SccgcNU9Tq6f8xmD4qefkibuAl/Z51t4e3rnR8Put37VBwbI15DDENsTnEf9vddp yzCmvmC8ai0YctA5ag9T52GV++zrrpQHhnTL+vaDuKQL1Sq6m7fKyX+o+TNyWNiJjqU3 m57EXiyol4TkD8xdV+QcOGgl46zYmculEUTFoafFOuuEWyvFXkX2SNW3FFsg7MFJ8Lvi x+sgGGAgyBsaIydDRpNCed6senC+LZheDBvxyGwyzjoZZ5uOMw3MyGF+H7B0dUDTzzSG kNzJIJrh93b+wktJTJJOoo+u+2GL3lgmgFVgAFT+E4DffGOz53M5kGJKSJ+871R7G6rd IJkw== X-Gm-Message-State: AOAM531zKuwrhP2d+85zNJc+RLgm0o1/EhIFaE2kPEuvovfhujRs4eSE H3oz6RGDnAryRPsAXftsbHs= X-Google-Smtp-Source: ABdhPJxtgToEh90OsCzFZ8X/0t8eT0FJAw1LQkF78w9cJu/2scgskfJvfnWyygm0lV6xkfQGigLdTA== X-Received: by 2002:a63:1026:: with SMTP id f38mr1582605pgl.142.1615855949298; Mon, 15 Mar 2021 17:52:29 -0700 (PDT) Received: from f8ffc2228008.ant.amazon.com ([54.240.193.129]) by smtp.gmail.com with ESMTPSA id gz12sm759496pjb.33.2021.03.15.17.52.24 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 15 Mar 2021 17:52:28 -0700 (PDT) Subject: Re: [PATCH] mm: memcontrol: switch to rstat fix To: Johannes Weiner , Andrew Morton Cc: Michal Hocko , Roman Gushchin , Shakeel Butt , Tejun Heo , =?UTF-8?Q?Michal_Koutn=c3=bd?= , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@fb.com References: <20210315234100.64307-1-hannes@cmpxchg.org> From: "Singh, Balbir" Message-ID: <494a5169-7e18-804b-3975-3a6442aff601@gmail.com> Date: Tue, 16 Mar 2021 11:52:22 +1100 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <20210315234100.64307-1-hannes@cmpxchg.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit X-Stat-Signature: bscdypfnrejb61na6r7wfnor1en576go X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 78DF22000383 Received-SPF: none (gmail.com>: No applicable sender policy available) receiver=imf18; identity=mailfrom; envelope-from=""; helo=mail-pg1-f181.google.com; client-ip=209.85.215.181 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1615855950-962558 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 16/3/21 10:41 am, Johannes Weiner wrote: > Fix a sleep in atomic section problem: wb_writeback() takes a spinlock > and calls wb_over_bg_thresh() -> mem_cgroup_wb_stats, but the regular > rstat flushing function called from in there does lockbreaking and may > sleep. Switch to the atomic variant, cgroup_rstat_irqsafe(). > > To be consistent with other memcg flush calls, but without adding > another memcg wrapper, inline and drop memcg_flush_vmstats() instead. > > Signed-off-by: Johannes Weiner > --- The patch make sense, but it does break any notion of abstraction we had about controllers have some independence in their strategy to maintain their own counters and stats. It now couples writeback with rstat instead of just memcg. Acked-by: Balbir Singh