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=-7.0 required=3.0 tests=INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 99F98C433DF for ; Mon, 15 Jun 2020 06:42:24 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 650D92067B for ; Mon, 15 Jun 2020 06:42:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 650D92067B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 124CA6B0006; Mon, 15 Jun 2020 02:42:24 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0FCFA6B0007; Mon, 15 Jun 2020 02:42:24 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F2D0C6B0008; Mon, 15 Jun 2020 02:42:23 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0232.hostedemail.com [216.40.44.232]) by kanga.kvack.org (Postfix) with ESMTP id D95796B0006 for ; Mon, 15 Jun 2020 02:42:23 -0400 (EDT) Received: from smtpin30.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id A6487356F for ; Mon, 15 Jun 2020 06:42:23 +0000 (UTC) X-FDA: 76930502166.30.army03_421760026df4 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin30.hostedemail.com (Postfix) with ESMTP id 88D41180B3AA7 for ; Mon, 15 Jun 2020 06:42:23 +0000 (UTC) X-HE-Tag: army03_421760026df4 X-Filterd-Recvd-Size: 3770 Received: from mail-wr1-f65.google.com (mail-wr1-f65.google.com [209.85.221.65]) by imf12.hostedemail.com (Postfix) with ESMTP for ; Mon, 15 Jun 2020 06:42:22 +0000 (UTC) Received: by mail-wr1-f65.google.com with SMTP id l11so15809902wru.0 for ; Sun, 14 Jun 2020 23:42:22 -0700 (PDT) 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:content-transfer-encoding :in-reply-to; bh=r5bbY+2GSPiy6U8SvmPVHs8hp2v5pEnTmjUC34UGuPc=; b=eMnEoOSAyb3KGiIaZiZ2jA61H+IgJjB4o0JZPO2EH0KoAuMrmsR2Mz0dWrbPURMfhG 7qr+OP1eeQuPrPKQEmqGO5F699ObQXyw0MoINYVrZ11cLQr6oHgkvwwi5AdHHhghhkPe EpOT8/Sl+v0e8pDrNfNsUSiQqxKe3ia7Ogwdzd9OSRWiKG4GL0UvbunYpMhTxBmdjp0D sj0pONPTXLbW05Z1TYHcwv8UnH7Hp7fzKChkyPFpruJApKeV41YWHUuNmVqubPrpXhnH sbsdCl7Oea8R+Q9u6gmJlCubVOHYafB6VTi0abOzGoUD9QEy+BrnqMfRaTSt0m1RdS93 1fyA== X-Gm-Message-State: AOAM531o/6toJXGz2sb6r3YInXLI/z1+X/1+F89EBPy5HdLyfiQowdl7 Q1zsmrM8DUb0rIZMp/cETdE= X-Google-Smtp-Source: ABdhPJzuZ4QyVs1o9eY/IW0ZUzlwf4irr7o0CATLvQzfHAqo+xJXFL4GQptQe8/gC8HJp3y5qGV8yg== X-Received: by 2002:adf:e4d1:: with SMTP id v17mr26738308wrm.224.1592203341583; Sun, 14 Jun 2020 23:42:21 -0700 (PDT) Received: from localhost (ip-37-188-174-201.eurotel.cz. [37.188.174.201]) by smtp.gmail.com with ESMTPSA id h27sm26967510wrb.18.2020.06.14.23.42.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 14 Jun 2020 23:42:20 -0700 (PDT) Date: Mon, 15 Jun 2020 08:42:19 +0200 From: Michal Hocko To: Chris Down Cc: Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Michal =?iso-8859-1?Q?Koutn=FD?= Subject: Re: [PATCH] mm, memcg: prevent missed memory.low load tears Message-ID: <20200615064219.GA25296@dhcp22.suse.cz> References: <20200612174437.GA391453@chrisdown.name> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20200612174437.GA391453@chrisdown.name> X-Rspamd-Queue-Id: 88D41180B3AA7 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 Content-Transfer-Encoding: quoted-printable 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 Fri 12-06-20 18:44:37, Chris Down wrote: > Looks like one of these got missed when massaging in f86b810c2610 ("mm, > memcg: prevent memory.low load/store tearing") with other linux-mm > changes. >=20 > Reported-by: Michal Koutn=FD > Signed-off-by: Chris Down Acked-by: Michal Hocko > --- > mm/memcontrol.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) >=20 > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 0b38b6ad547d..f7cc66a80348 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -6416,7 +6416,7 @@ enum mem_cgroup_protection mem_cgroup_protected(s= truct mem_cgroup *root, > =20 > if (parent =3D=3D root) { > memcg->memory.emin =3D READ_ONCE(memcg->memory.min); > - memcg->memory.elow =3D memcg->memory.low; > + memcg->memory.elow =3D READ_ONCE(memcg->memory.low); > goto out; > } > =20 > @@ -6428,7 +6428,8 @@ enum mem_cgroup_protection mem_cgroup_protected(s= truct mem_cgroup *root, > atomic_long_read(&parent->memory.children_min_usage))); > =20 > WRITE_ONCE(memcg->memory.elow, effective_protection(usage, parent_usa= ge, > - memcg->memory.low, READ_ONCE(parent->memory.elow), > + READ_ONCE(memcg->memory.low), > + READ_ONCE(parent->memory.elow), > atomic_long_read(&parent->memory.children_low_usage))); > =20 > out: > --=20 > 2.27.0 >=20 --=20 Michal Hocko SUSE Labs