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From: Oleg Nesterov <oleg@redhat.com>
To: Tejun Heo <tj@kernel.org>
Cc: rjw@sisk.pl, paul@paulmenage.org, linux-kernel@vger.kernel.org,
	arnd@arndb.de, Li Zefan <lizf@cn.fujitsu.com>
Subject: Re: [PATCH 13/16] cgroup_freezer: prepare for removal of TIF_FREEZE
Date: Sun, 28 Aug 2011 19:39:54 +0200	[thread overview]
Message-ID: <20110828173954.GA26588@redhat.com> (raw)
In-Reply-To: <1313763382-12341-14-git-send-email-tj@kernel.org>

Hi Tejun.

Well, yet another sorry for delay ;)

On 08/19, Tejun Heo wrote:
>
> @@ -279,7 +268,6 @@ static int try_to_freeze_cgroup(struct cgroup *cgroup, struct freezer *freezer)
>  	struct task_struct *task;
>  	unsigned int num_cant_freeze_now = 0;
>
> -	freezer->state = CGROUP_FREEZING;

...

> @@ -321,6 +307,8 @@ static int freezer_change_state(struct cgroup *cgroup,
>  	if (goal_state == freezer->state)
>  		goto out;
>
> +	freezer->state = goal_state;
> +

This doesn't look right at all... Unless I misssed something.

A user writes "FROZEN" into the control file, our goal is CGROUP_FROZEN.

But. freezer_change_state() should set CGROUP_FREEZING, not CGROUP_FROZEN.
This cgrp is not frozen yet, _FROZEN should be set by update_if_frozen(),
assuming that the user reads the state waiting until the operation
completes.

Oleg.


  parent reply	other threads:[~2011-08-28 17:43 UTC|newest]

Thread overview: 79+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-08-19 14:16 [PATCHSET] freezer: fix various bugs and simplify implementation Tejun Heo
2011-08-19 14:16 ` [PATCH 01/16] freezer: fix current->state restoration race in refrigerator() Tejun Heo
2011-08-19 15:52   ` Oleg Nesterov
2011-08-19 16:11     ` Tejun Heo
2011-08-19 21:08   ` Rafael J. Wysocki
2011-08-20  8:13     ` Tejun Heo
2011-08-19 14:16 ` [PATCH 02/16] freezer: don't unnecessarily set PF_NOFREEZE explicitly Tejun Heo
2011-08-19 16:43   ` Gustavo Padovan
2011-08-22 15:05   ` Samuel Ortiz
2011-08-19 14:16 ` [PATCH 03/16] freezer: unexport refrigerator() and update try_to_freeze() slightly Tejun Heo
2011-08-19 14:16 ` [PATCH 04/16] freezer: implement and use kthread_freezable_should_stop() Tejun Heo
2011-08-19 20:07   ` Henrique de Moraes Holschuh
2011-08-21 19:14   ` Oleg Nesterov
2011-08-22  9:53     ` Tejun Heo
2011-08-23 15:42       ` Oleg Nesterov
2011-08-19 14:16 ` [PATCH 05/16] freezer: rename thaw_process() to __thaw_task() and simplify the implementation Tejun Heo
2011-08-19 15:37   ` Paul Menage
2011-08-24  2:28   ` Matt Helsley
2011-08-19 14:16 ` [PATCH 06/16] freezer: make exiting tasks properly unfreezable Tejun Heo
2011-08-23 15:52   ` Oleg Nesterov
2011-08-23 19:44     ` Tejun Heo
2011-08-24 14:14       ` Oleg Nesterov
2011-08-25 15:59         ` Tejun Heo
2011-08-25 16:56           ` Oleg Nesterov
2011-08-25 21:01             ` Rafael J. Wysocki
2011-08-25 21:54               ` Tejun Heo
2011-08-26 21:09                 ` Rafael J. Wysocki
2011-08-27 10:35                   ` Tejun Heo
2011-08-27 10:51                     ` Rafael J. Wysocki
2011-08-27 11:02                       ` Tejun Heo
2011-08-27 12:22                         ` Rafael J. Wysocki
2011-08-25 21:52             ` Tejun Heo
2011-08-24 22:34   ` Matt Helsley
2011-08-25 15:25     ` Oleg Nesterov
2011-08-25 16:11     ` Tejun Heo
2011-08-19 14:16 ` [PATCH 07/16] freezer: don't distinguish nosig tasks on thaw Tejun Heo
2011-08-19 21:14   ` Rafael J. Wysocki
2011-08-20  8:10     ` Tejun Heo
2011-08-20  8:39       ` Rafael J. Wysocki
2011-08-19 14:16 ` [PATCH 08/16] freezer: use dedicated lock instead of task_lock() + memory barrier Tejun Heo
2011-08-28 17:51   ` Oleg Nesterov
2011-08-28 18:21     ` Oleg Nesterov
2011-08-29  7:20     ` Tejun Heo
2011-08-19 14:16 ` [PATCH 09/16] freezer: make freezing indicate freeze condition in effect Tejun Heo
2011-08-28 17:56   ` Oleg Nesterov
2011-08-29  7:31     ` Tejun Heo
2011-08-29 17:44     ` Oleg Nesterov
2011-08-19 14:16 ` [PATCH 10/16] freezer: fix set_freezable[_with_signal]() race Tejun Heo
2011-08-28 18:01   ` Oleg Nesterov
2011-08-29  7:38     ` Tejun Heo
2011-08-19 14:16 ` [PATCH 11/16] freezer: kill PF_FREEZING Tejun Heo
2011-08-19 14:16 ` [PATCH 12/16] freezer: clean up freeze_processes() failure path Tejun Heo
2011-08-28 18:09   ` Oleg Nesterov
2011-08-29  7:28     ` Tejun Heo
2011-08-29  7:40       ` Rafael J. Wysocki
2011-08-19 14:16 ` [PATCH 13/16] cgroup_freezer: prepare for removal of TIF_FREEZE Tejun Heo
2011-08-19 15:40   ` Paul Menage
2011-08-28 17:39   ` Oleg Nesterov [this message]
2011-08-29  6:30     ` Tejun Heo
2011-08-19 14:16 ` [PATCH 14/16] freezer: make freezing() test freeze conditions in effect instead " Tejun Heo
2011-08-19 15:43   ` Paul Menage
2011-08-29 15:49   ` Oleg Nesterov
2011-08-29 15:56     ` Oleg Nesterov
2011-08-29 16:30       ` Oleg Nesterov
2011-08-29 16:17     ` Oleg Nesterov
2011-08-19 14:16 ` [PATCH 15/16] freezer: remove now unused TIF_FREEZE Tejun Heo
2011-08-19 14:16 ` [PATCH 16/16] freezer: remove should_send_signal() and update frozen() Tejun Heo
2011-08-19 14:23 ` [PATCHSET] freezer: fix various bugs and simplify implementation Tejun Heo
2011-08-19 15:34   ` Paul Menage
2011-08-19 16:25   ` Tejun Heo
2011-08-24  1:10     ` Matt Helsley
2011-08-19 21:00 ` Rafael J. Wysocki
2011-08-20  8:14   ` Tejun Heo
2011-09-05  8:52   ` [BUG] CPU hotplug, freezer: Freezing of tasks failed after 20.00 seconds Srivatsa S. Bhat
2011-09-05 14:15     ` Tejun Heo
2011-09-06  5:08       ` Tejun Heo
2011-09-06  6:01         ` Rafael J. Wysocki
2011-10-02 19:13           ` Srivatsa S. Bhat
2011-10-02 19:33             ` Rafael J. Wysocki

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