Messages in this thread | | | Date | Mon, 22 Oct 2012 21:25:06 +0200 | From | Oleg Nesterov <> | Subject | Re: [PATCH 5/7] cgroup_freezer: allow moving tasks in and out of a frozen cgroup |
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Tha last question ;)
On 10/16, Tejun Heo wrote: > > @@ -190,12 +201,12 @@ static void freezer_fork(struct task_struct *task) > goto out; > > spin_lock_irq(&freezer->lock); > - BUG_ON(freezer->state == CGROUP_FROZEN); > - > - /* Locking avoids race with FREEZING -> THAWED transitions. */ > - if (freezer->state == CGROUP_FREEZING) > + /* > + * @task might have been just migrated into a FROZEN cgroup.
Confused. If it was migrated, then freezer_attach() should take care do freeze_task?
IOW,
> Test > + * equality with THAWED. Read the comment in freezer_attach(). > + */ > + if (freezer->state != CGROUP_THAWED) > freeze_task(task); > -
This can only happen in the "normal" case, when a CGROUP_FREEZING task forks the new child. So we could even do BUG_ON(state = CGROUP_FROZEN).
Or there could be another reason?
Oleg.
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