On Saturday, 14 July 2007 01:43, Pavel Machek wrote: > Hi! > > > There is the problem with try_to_freeze_tasks() that it always loops until the > > timeout expires, even if it is certain to fail much earlier. Namely, if there > > are uninterruptible tasks waiting for some frozen tasks to let them continue, > > try_to_freeze_tasks() will certainly fail and it shouldn't waste time in that > > cases. > > > > To detect such situations, we can check if the number of tasks that haven't > > frozen yet changes between subsequent iterations of the main loop in > > try_to_freeze_tasks(). If this number hasn't been changing for sufficiently > > long time (say, 250 ms), then most probably some uninterruptible tasks are > > blocked by some frozen tasks and we should break out of this stalemate. Thus, > > it seems reasonable to thaw the tasks that have already been frozen without > > clearing the freeze requests of the tasks that are refusing to freeze. This > > way, if these tasks are really blocked by the frozen ones, they will get extra > > chance to freeze themselves after we have thawed the other tasks and before we > > request those tasks to freeze again. Next, the freezing loop can be repeated > > and so on, until all tasks are frozen or the timeout expires. > > I still don't quite like this patch... it is kind of trick we should > not have to play. Can we at least get confirmation it helps in the > FUSE case? Well, anyone having problems with FUSE vs the freezer please check. :-) I think I'll send the series to Andrew without this patch. Would that be OK? 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
