On Tuesday, 10 July 2007 01:34, Pavel Machek wrote: > Hi! > > > From: Rafael J. Wysocki <rjw@xxxxxxx> > > > > The freezer fails if there are uninterruptible tasks waiting for some frozen > > tasks to let them continue. Moreover, in that case try_to_freeze_tasks() loops > > uselessly until the timeout expires which is wasteful, so in principle we should > > make the freezer fail as soon as all the tasks that refuse to freeze are > > uninterruptible. However, instead of failing the freezer we can try to use the > > time left and thaw the tasks that have already been frozen without > > clearing the > > No, we can't do that: > > Imagine we have single uninterruptible task that waits for disk. It > would exit uninterruptible state in 10msec, *but* you give up and > unfreeze all. Now, another task goes uninterruptible waiting for > disk and situation repeats. Livelock. For how many times would that have to repeat before 30s of timeout expires? Sorry, but I don't buy this argument. :-) > Yes, this might play with races in interresting ways and help fuse, > but we do not want the livelock in the first place. I think that the "livelock" will never happen. Besides, we can add another timeout for breaking the loop from a "locked up" state. Anyway, waiting for 20s (as without the patch) when it is _certain_ that we will fail doesn't make sense ... Greetings, Rafael -- "Premature optimization is the root of all evil." - Donald Knuth _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
