From: "Michal Koutný" <mkoutny@suse.com>
To: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <guro@fb.com>,
Andrew Morton <akpm@linux-foundation.org>,
Shakeel Butt <shakeelb@google.com>,
Michal Hocko <mhocko@kernel.org>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
kernel-team@fb.com
Subject: Re: [PATCH v4 4/4] mm: convert page kmemcg type to a page memcg flag
Date: Fri, 2 Oct 2020 12:03:50 +0200 [thread overview]
Message-ID: <20201002100350.GC24008@blackbody.suse.cz> (raw)
In-Reply-To: <20201001172713.GA500308@cmpxchg.org>
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On Thu, Oct 01, 2020 at 01:27:13PM -0400, Johannes Weiner <hannes@cmpxchg.org> wrote:
> The activation code is the only path where page migration is not
> excluded. Because unlike with page state statistics, we don't really
> mind a race when counting an activation event.
Thanks for the explanation. I see why the accessor trio is justified.
> I do think there is a bug, though: mem_cgroup_move_account() should
> use WRITE_ONCE() on page->mem_cgroup.
If this were a bug, wouldn't be the proper approach
rcu_assign_pointer()/rcu_dereference() pair?
Michal
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next prev parent reply other threads:[~2020-10-02 10:03 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-01 0:27 [PATCH v4 0/4] mm: allow mapping accounted kernel pages to userspace Roman Gushchin
2020-10-01 0:27 ` [PATCH v4 1/4] mm: memcontrol: use helpers to access page's memcg data Roman Gushchin
2020-10-01 13:46 ` Johannes Weiner
2020-10-01 18:27 ` Roman Gushchin
2020-10-01 18:59 ` Johannes Weiner
2020-10-01 20:51 ` Roman Gushchin
2020-10-02 14:22 ` Johannes Weiner
2020-10-01 0:27 ` [PATCH v4 2/4] mm: memcontrol/slab: use helpers to access slab page's memcg_data Roman Gushchin
2020-10-01 0:27 ` [PATCH v4 3/4] mm: introduce page memcg flags Roman Gushchin
2020-10-01 13:44 ` Johannes Weiner
2020-10-01 0:27 ` [PATCH v4 4/4] mm: convert page kmemcg type to a page memcg flag Roman Gushchin
2020-10-01 13:48 ` Johannes Weiner
2020-10-01 17:00 ` Michal Koutný
2020-10-01 17:27 ` Johannes Weiner
2020-10-02 10:03 ` Michal Koutný [this message]
2020-10-02 13:25 ` Johannes Weiner
2020-10-01 18:30 ` Roman Gushchin
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