Messages in this thread | | | Date | Thu, 1 Mar 2007 16:39:08 +0000 | From | Pavel Machek <> | Subject | Re: [PATCH -mm 2/7] Freezer: Close theoretical race between refrigerator and thaw_tasks |
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On Thu 2007-03-01 16:08:12, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rjw@sisk.pl> > > If the freezing of tasks fails and a task is preempted in refrigerator() before > calling frozen_process(), then thaw_tasks() may run before this task is frozen. > In that case the task will freeze and no one will thaw it. > > To fix this race we can call freezing(current) in refrigerator() along with > frozen_process(current) under the task_lock() which also should be taken in > the error path of try_to_freeze_tasks() as well as in thaw_process(). Moreover, > if thaw_process() additionally clears TIF_FREEZE for tasks that are not frozen, > we can be sure that all tasks are thawed and there are no pending "freeze" > requests after thaw_tasks() has run. > > Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
ack. -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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