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=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 83360C4332B for ; Fri, 20 Mar 2020 02:29:56 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3AC352051A for ; Fri, 20 Mar 2020 02:29:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="vDXaRu7S" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3AC352051A 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 C60DA6B0003; Thu, 19 Mar 2020 22:29:55 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C125E6B0006; Thu, 19 Mar 2020 22:29:55 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B26BF6B0007; Thu, 19 Mar 2020 22:29:55 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0248.hostedemail.com [216.40.44.248]) by kanga.kvack.org (Postfix) with ESMTP id 975DF6B0003 for ; Thu, 19 Mar 2020 22:29:55 -0400 (EDT) Received: from smtpin14.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 7260F181AC9CB for ; Fri, 20 Mar 2020 02:29:55 +0000 (UTC) X-FDA: 76614160350.14.earth79_3981dd9407030 X-HE-Tag: earth79_3981dd9407030 X-Filterd-Recvd-Size: 4156 Received: from mail-pj1-f66.google.com (mail-pj1-f66.google.com [209.85.216.66]) by imf06.hostedemail.com (Postfix) with ESMTP for ; Fri, 20 Mar 2020 02:29:55 +0000 (UTC) Received: by mail-pj1-f66.google.com with SMTP id q16so2902663pje.1 for ; Thu, 19 Mar 2020 19:29:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=Ej2t2tjTTi+dCG7kv+HYacocLU7lAp9S3sagGpnffm0=; b=vDXaRu7SyCtxh9coTJy8Mi/ewQWFK2XPdAaYQ7b5r1BkQYv/eqIBdkqcMMZFiat4IM WJXss3cEewTZ7QXfRq5NaBdVY9P0dqU18LzBPNb/DXaLui/PYye5o3PRt+ionGtz3abk uM0recez2aeO3zR+NR4/mieVcBNv2iX5oQ/s+DFbUzddHcXrxRKOJXk426FqWotzYTzu LJJELuM2SLbLMwruuyMQN4CmoAX3txDQlLCUEWZUY2lRNxiA1/6sudpQV9LROrMTdGT9 kShCViYCuezTZFIzVIcyYezLbLOaoMeGzsz28QPNBTzq+5d0JXLa0UdjS5iAKdKTxomd 7+rg== 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:user-agent; bh=Ej2t2tjTTi+dCG7kv+HYacocLU7lAp9S3sagGpnffm0=; b=aF/TVL5IOViBqw36ne+kRZa24rHMYn/vSKzSWiWE0lhVYcAZy7eLKCUytUKuIhkhg1 NGkBg3r8zE0vzHmJhyYy0pf+vnKXjFuJvYl3YjED4jziw/lIkTwg66gFro9twWaGptq4 mV8EGmp8hijNMUCmsGJho2JQpAKkG99liYoWojCVgGWTwXcWr269xzGCenkh2Cc10G+o uFbM6avsoxODC5EUo7h7U4f0obG+cfYTrvAlm4byzpTbGnOLNts0z4xXN0dIUSsDzS+J N1lkXkJjgY3NzrrlnQ7fN9sEs4mUoWxtO8TXkgocE8XdS05jGJA7oL4IkBEo/fpLBvn0 VsGw== X-Gm-Message-State: ANhLgQ05KJAc4VZgH3lkJqovY3zndHRO+GXO0/OovwLm7NtJE0abQX4v rj3jWaXMrXr+c/Bl29qxxy4= X-Google-Smtp-Source: ADFU+vt5YNa7zX/ujkhHP+GNwPbwsiEe6OXvKgbAsErL3KgwcoZjUJNnu5gAwiC8aLoOV7LgEfKvRg== X-Received: by 2002:a17:90b:24c:: with SMTP id fz12mr6886992pjb.22.1584671393776; Thu, 19 Mar 2020 19:29:53 -0700 (PDT) Received: from localhost ([43.224.245.179]) by smtp.gmail.com with ESMTPSA id f19sm3530437pgf.33.2020.03.19.19.29.52 (version=TLS1_2 cipher=AES128-SHA bits=128/128); Thu, 19 Mar 2020 19:29:53 -0700 (PDT) Date: Fri, 20 Mar 2020 10:29:50 +0800 From: chenqiwu To: Matthew Wilcox Cc: Chris Down , akpm@linux-foundation.org, linux-mm@kvack.org, chenqiwu Subject: Re: [PATCH] mm/vmscan: fix incorrect return type for cgroup_reclaim() Message-ID: <20200320022950.GB31830@cqw-OptiPlex-7050> References: <1584633026-26288-1-git-send-email-qiwuchen55@gmail.com> <20200319162025.GA237751@chrisdown.name> <20200319173606.GL22433@bombadil.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200319173606.GL22433@bombadil.infradead.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-Bogosity: Ham, tests=bogofilter, spamicity=0.114981, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Mar 19, 2020 at 10:36:06AM -0700, Matthew Wilcox wrote: > On Thu, Mar 19, 2020 at 04:20:25PM +0000, Chris Down wrote: > > I think this is actually the important bit. For those who build > their kernels with cgroups disabled, it will save a small number of > instructions since cgroup_reclaim() will be NULL rather than dereferencing > sc->target_mem_group. It'd be nice to have that saving quantified as > part of the changelog. I agree. > > > > @@ -2625,7 +2626,7 @@ static inline bool should_continue_reclaim(struct pglist_data *pgdat, > > > > > > static void shrink_node_memcgs(pg_data_t *pgdat, struct scan_control *sc) > > > { > > > - struct mem_cgroup *target_memcg = sc->target_mem_cgroup; > > > + struct mem_cgroup *target_memcg = cgroup_reclaim(sc); > > It feels like the name is wrong, doesn't it? cgroup_reclaim() doesn't > really scream to me "I return a mem_cgroup pointer". I can't think of > a good name, but maybe someone else can. > I can't think of a good name, too. Maybe we just keep it unchanged if nobody else can.