From: Oleg Nesterov <oleg@redhat.com>
To: Tejun Heo <tj@kernel.org>
Cc: matthltc@us.ibm.com, rjw@sisk.pl, paul@paulmenage.org,
containers@lists.linux-foundation.org,
linux-pm@lists.linux-foundation.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/6] cgroup_freezer: fix freezer->state setting bug in freezer_change_state()
Date: Sun, 4 Sep 2011 20:02:06 +0200 [thread overview]
Message-ID: <20110904180206.GA28520@redhat.com> (raw)
In-Reply-To: <1314988070-12244-2-git-send-email-tj@kernel.org>
On 09/03, Tejun Heo wrote:
>
> @@ -308,24 +308,24 @@ static int freezer_change_state(struct cgroup *cgroup,
> spin_lock_irq(&freezer->lock);
>
> update_if_frozen(cgroup, freezer);
> - if (goal_state == freezer->state)
> - goto out;
> -
> - freezer->state = goal_state;
>
> switch (goal_state) {
> case CGROUP_THAWED:
> - atomic_dec(&system_freezing_cnt);
> + if (freezer->state != CGROUP_THAWED)
> + atomic_dec(&system_freezing_cnt);
> + freezer->state = CGROUP_THAWED;
> unfreeze_cgroup(cgroup, freezer);
> break;
> case CGROUP_FROZEN:
> - atomic_inc(&system_freezing_cnt);
> + if (freezer->state == CGROUP_THAWED)
> + atomic_inc(&system_freezing_cnt);
> + freezer->state = CGROUP_FREEZING;
> retval = try_to_freeze_cgroup(cgroup, freezer);
Cough. Now it doesn't look right to me ;)
If the user write "FROZEN" into the control file, we should not
turn the CGROUP_FROZEN state into CGROUP_FREEZING. Probably this
is harmless, but this looks wrong and this doesn't match the
current behaviour, user-visible change.
Oleg.
next prev parent reply other threads:[~2011-09-04 18:06 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-02 18:27 [PATCHSET pm-freezer] freezer: fixes & simplifications Tejun Heo
2011-09-02 18:27 ` [PATCH 1/6] cgroup_freezer: fix freezer->state setting bug in freezer_change_state() Tejun Heo
2011-09-04 18:02 ` Oleg Nesterov [this message]
2011-09-04 18:11 ` Tejun Heo
2011-09-04 18:20 ` Oleg Nesterov
2011-09-02 18:27 ` [PATCH 2/6] freezer: set PF_NOFREEZE on a dying task right before TASK_DEAD " Tejun Heo
2011-09-02 18:27 ` [PATCH 3/6] freezer: restructure __refrigerator() Tejun Heo
2011-09-02 18:27 ` [PATCH 4/6] freezer: use lock_task_sighand() in fake_signal_wake_up() Tejun Heo
2011-09-02 18:27 ` [PATCH 5/6] freezer: remove unused @sig_only from freeze_task() Tejun Heo
2011-09-02 18:27 ` [PATCH 6/6] freezer: kill unused set_freezable_with_signal() Tejun Heo
2011-09-04 18:46 ` Oleg Nesterov
2011-09-05 2:33 ` Tejun Heo
2011-09-05 2:35 ` Tejun Heo
2011-09-05 16:21 ` Oleg Nesterov
2011-09-05 16:20 ` Oleg Nesterov
2011-09-06 3:28 ` Tejun Heo
2011-09-06 15:18 ` Oleg Nesterov
2011-09-06 15:25 ` Oleg Nesterov
2011-09-06 15:53 ` Tejun Heo
2011-09-07 18:21 ` [PATCH 0/1] freezer: fix wait_event_freezable/__thaw_task races Oleg Nesterov
2011-09-07 18:22 ` [PATCH 1/1] " Oleg Nesterov
2011-09-08 1:05 ` Tejun Heo
2011-09-08 17:59 ` Oleg Nesterov
2011-09-11 1:54 ` Tejun Heo
2011-09-11 18:29 ` Oleg Nesterov
2011-09-11 18:41 ` Oleg Nesterov
2011-09-08 18:01 ` [PATCH 6/6] freezer: kill unused set_freezable_with_signal() Matt Helsley
2011-09-11 1:37 ` Tejun Heo
2011-09-04 18:48 ` [PATCHSET pm-freezer] freezer: fixes & simplifications Oleg Nesterov
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