From: Michal Hocko <mhocko@kernel.org>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
David Rientjes <rientjes@google.com>,
Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] proc_oom_score: remove tasklist_lock and pid_alive()
Date: Thu, 9 Jun 2016 08:44:56 +0200 [thread overview]
Message-ID: <20160609064455.GB24777@dhcp22.suse.cz> (raw)
In-Reply-To: <20160608211921.GA15508@redhat.com>
On Wed 08-06-16 23:19:21, Oleg Nesterov wrote:
> This was needed before to ensure that ->signal != 0 and do_each_thread()
> is safe, see the commit b95c35e76b29b for details.
>
> Today tsk->signal can't go away and for_each_thread(tsk) is always safe.
>
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
> ---
> fs/proc/base.c | 7 ++-----
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/fs/proc/base.c b/fs/proc/base.c
> index a11eb71..93e7754 100644
> --- a/fs/proc/base.c
> +++ b/fs/proc/base.c
> @@ -579,11 +579,8 @@ static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
> unsigned long totalpages = totalram_pages + total_swap_pages;
> unsigned long points = 0;
>
> - read_lock(&tasklist_lock);
> - if (pid_alive(task))
> - points = oom_badness(task, NULL, NULL, totalpages) *
> - 1000 / totalpages;
> - read_unlock(&tasklist_lock);
> + points = oom_badness(task, NULL, NULL, totalpages) *
> + 1000 / totalpages;
> seq_printf(m, "%lu\n", points);
>
> return 0;
> --
> 2.5.0
>
--
Michal Hocko
SUSE Labs
prev parent reply other threads:[~2016-06-09 6:45 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-08 21:19 [PATCH] proc_oom_score: remove tasklist_lock and pid_alive() Oleg Nesterov
2016-06-08 22:48 ` David Rientjes
2016-06-09 6:44 ` Michal Hocko [this message]
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