On Wed 2008-05-07 20:41:19, Rafael J. Wysocki wrote: > On Wednesday, 7 of May 2008, Matthew Wilcox wrote: > > On Wed, May 07, 2008 at 12:07:55AM +0200, Rafael J. Wysocki wrote: > > > The introduction of TASK_KILLABLE allows the freezer to work in some situation > > > that it could not handle before. > > > > > > Make the freezer handle killable tasks and add try_to_freeze() in some places > > > where it is safe to freeze a (killable) task. Introduce the > > > wait_event_killable_freezable() macro to be used wherever the freezing of > > > a waiting killable task is desirable. > > > > Why do you say that TASK_KILLABLE allows the freezer to work in some > > situations where it couldn't before? If something's using one of the > > killable functions, it means that it knows how to clean up and unwind > > gracefully if the task receives a fatal signal. I don't understand what > > connection there is to the freezer. > > The reason why we don't freeze uninterruptible tasks is that we don't know > why they are in that state. If one of tasks is uninterruptible for a > relatively long time, that may indicate a non-recoverable error making it > dangerous to put the system into a sleep state. If the task is killable, > though, the situation is recoverable. ....but the task may still hold some locks, so we can't "just freeze it". Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
