From: David Rientjes <rientjes@google.com>
To: Wei Yang <richardw.yang@linux.intel.com>
Cc: hannes@cmpxchg.org, mhocko@kernel.org, vdavydov.dev@gmail.com,
akpm@linux-foundation.org, kirill.shutemov@linux.intel.com,
cgroups@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, yang.shi@linux.alibaba.com
Subject: Re: [RFC PATCH] mm: thp: grab the lock before manipulation defer list
Date: Fri, 3 Jan 2020 16:44:59 -0800 (PST) [thread overview]
Message-ID: <alpine.DEB.2.21.2001031642530.92066@chino.kir.corp.google.com> (raw)
In-Reply-To: <20200103233925.GA3678@richard>
On Sat, 4 Jan 2020, Wei Yang wrote:
> On Fri, Jan 03, 2020 at 11:29:06AM -0800, David Rientjes wrote:
> >On Fri, 3 Jan 2020, Wei Yang wrote:
> >
> >> As all the other places, we grab the lock before manipulate the defer list.
> >> Current implementation may face a race condition.
> >>
> >> Fixes: 87eaceb3faa5 ("mm: thp: make deferred split shrinker memcg aware")
> >>
> >> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
> >>
> >> ---
> >> I notice the difference during code reading and just confused about the
> >> difference. No specific test is done since limited knowledge about cgroup.
> >>
> >> Maybe I miss something important?
> >
> >The check for !list_empty(page_deferred_list(page)) must certainly be
> >serialized with doing list_del_init(page_deferred_list(page)).
> >
>
> Hi David
>
> Would you mind giving more information? You mean list_empty and list_del_init
> is atomic?
>
I mean your patch is obviously correct :) It should likely also have a
stable@vger.kernel.org # 5.4+
Acked-by: David Rientjes <rientjes@google.com>
next prev parent reply other threads:[~2020-01-04 0:45 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-03 14:34 Wei Yang
2020-01-03 19:29 ` David Rientjes
2020-01-03 23:39 ` Wei Yang
2020-01-04 0:44 ` David Rientjes [this message]
2020-01-06 1:20 ` Wei Yang
2020-01-06 10:23 ` Michal Hocko
2020-01-07 1:22 ` Wei Yang
2020-01-07 8:38 ` Michal Hocko
2020-01-08 0:35 ` Wei Yang
2020-01-08 9:40 ` Michal Hocko
2020-01-09 2:03 ` Wei Yang
2020-01-09 8:34 ` Michal Hocko
2020-01-09 3:18 ` Wei Yang
2020-01-09 8:36 ` Michal Hocko
2020-01-09 8:52 ` Wei Yang
2020-01-06 16:18 ` Alexander Duyck
2020-01-07 1:26 ` Wei Yang
2020-01-07 2:07 ` David Rientjes
2020-01-07 2:33 ` Wei Yang
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