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From:   Qian Cai <cai@lca.pw>
Mime-Version: 1.0 (1.0)
Subject: Re: [PATCH] mm: fix a data race in put_page()
Date:   Thu, 6 Feb 2020 18:55:57 -0500
Message-Id: <B1A2958B-5FB4-458B-8BE7-73047790CE0B@lca.pw>
References: <079c4429-8a11-154d-cf5c-473d2698d18d@nvidia.com>
Cc:     Jan Kara <jack@suse.cz>, David Hildenbrand <david@redhat.com>,
        akpm@linux-foundation.org, ira.weiny@intel.com,
        dan.j.williams@intel.com, elver@google.com, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
In-Reply-To: <079c4429-8a11-154d-cf5c-473d2698d18d@nvidia.com>
To:     John Hubbard <jhubbard@nvidia.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


> On Feb 6, 2020, at 6:34 PM, John Hubbard <jhubbard@nvidia.com> wrote:
>=20
> * data_race(): there is no race on the N bits worth of page zone number da=
ta. There
>  is only a perceived race, due to tools that look at word-level granularit=
y.

I=E2=80=99d like to think this from the compiler level. There is a data race=
 from the compiler load and store point of view. It is just in the case it i=
s harmless to affect the actual code logic.=