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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, 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 937F8C433B4 for ; Fri, 30 Apr 2021 05:56:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7910A61476 for ; Fri, 30 Apr 2021 05:56:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229482AbhD3F4y (ORCPT ); Fri, 30 Apr 2021 01:56:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:49274 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230215AbhD3F4x (ORCPT ); Fri, 30 Apr 2021 01:56:53 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id A576261476; Fri, 30 Apr 2021 05:56:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1619762165; bh=hGEwIJBktLsk9Ez2TwB9RJVVkoujpdUbhQ9YSjHc/lI=; h=Date:From:To:Subject:In-Reply-To:From; b=xDwtqVFvI9QS8+E7nZTAVvM0hDwwtFhTGcni1AL6THeA/YD/zeiR8/am2DwnkZleJ BiJXl1WlxTqwJGnuF9MW0s7dJuZYz9T3c3OkzM06DjpTRyBexN9aOwxFwk8aVGkY9W EFiX40Cwaufv1Lk1eZGjA8n39qbYsnw0qZv+Zc5E= Date: Thu, 29 Apr 2021 22:56:05 -0700 From: Andrew Morton To: akpm@linux-foundation.org, guro@fb.com, hannes@cmpxchg.org, linux-mm@kvack.org, mhocko@suse.com, mm-commits@vger.kernel.org, shakeelb@google.com, torvalds@linux-foundation.org Subject: [patch 057/178] memcg: cleanup root memcg checks Message-ID: <20210430055605.GZJjrVveZ%akpm@linux-foundation.org> In-Reply-To: <20210429225251.02b6386d21b69255b4f6c163@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Shakeel Butt Subject: memcg: cleanup root memcg checks Replace the implicit checking of root memcg with explicit root memcg checking i.e. !css->parent with mem_cgroup_is_root(). Link: https://lkml.kernel.org/r/20210223205625.2792891-1-shakeelb@google.com Signed-off-by: Shakeel Butt Acked-by: Michal Hocko Acked-by: Johannes Weiner Cc: Roman Gushchin Signed-off-by: Andrew Morton --- mm/memcontrol.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/mm/memcontrol.c~memcg-cleanup-root-memcg-checks +++ a/mm/memcontrol.c @@ -4123,7 +4123,7 @@ static int mem_cgroup_swappiness_write(s if (val > 100) return -EINVAL; - if (css->parent) + if (!mem_cgroup_is_root(memcg)) memcg->swappiness = val; else vm_swappiness = val; @@ -4473,7 +4473,7 @@ static int mem_cgroup_oom_control_write( struct mem_cgroup *memcg = mem_cgroup_from_css(css); /* cannot set to root cgroup and only 0 and 1 are allowed */ - if (!css->parent || !((val == 0) || (val == 1))) + if (mem_cgroup_is_root(memcg) || !((val == 0) || (val == 1))) return -EINVAL; memcg->oom_kill_disable = val; _