Hi!
> Currently, if a task is stopped (ie. it's in the TASK_STOPPED state), it is
> considered by the freezer as unfreezeable. However, there may be a race
> between the freezer and the delivery of the continuation signal to the task
> resulting in the task running after we have finished freezing other tasks.
> This, in turn, may lead to undesirable effects up to and including a
> corruption of data.
>
> To prevent this from happening we first need to make the freezer consider
> stopped tasks as freezeable. For this purpose we need to make freezeable()
> stop returning 0 for these tasks. We must remember, however, that the
> stopped tasks need not receive the continuation signal before thaw_processes()
> is called, so as soon as PF_FREEZE is set for them try_to_freeze_tasks()
> should stop counting them as the ones to wait for. Additionally, if there's a
> traced task (ie. a task in the TASK_TRACED state) the parent of which has
> PF_FREEZE set and is stopped, try_to_freeze_tasks() should not wait for it.
> Moreover, if there are some stopped tasks that haven't received the
> continuation
> signal before thaw_processes() is called, we must clear PF_FREEZE for them so
> that they don't go to the refrigerator when it's no longer desirable.
>
> Still if a stopped tasks receives the continuation signal after the freezer
> has returned, it should immediately go to the refrigerator. For this reason
> we need to place the call to try_to_freeze() in get_signal_to_deliver() right
> after the relock label.
>
> It is also reasonable to change the error paths so that the names of stopped
> or traced tasks which have not frozen are not reported to the user, because in
> the majority of cases they would be false positives.
>
> Signed-off-by: Rafael J. Wysocki <[EMAIL PROTECTED]>
Okay, lets go ahead with this one. (ACK) I still think we should be
able to find some simpler solution, I'll take a look.
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures)
http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
-------------------------------------------------------------------------
Take Surveys. Earn Cash. Influence the Future of IT
Join SourceForge.net's Techsay panel and you'll get the chance to share your
opinions on IT & business topics through brief surveys - and earn cash
http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV
_______________________________________________
Suspend-devel mailing list
Suspend-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/suspend-devel
