Hi! > > Freezer is not needed for snapshot -- it is needed so that we can > > write out the snapshot to disk without the need for special > > drivers/block/simple-ide-for-suspend.c. (We are doing snapshot, then > > write to disk from userland code in uswsusp). > > Yes. > > BTW, this patch: > > http://www.sisk.pl/kernel/hibernation_and_suspend/2.6.22-rc7/patches/15-freezer-make-kernel-threads-nonfreezable-by-default.patch > > that's queued up in -mm contains a freezer documentation update, in which the > reasons of using it, as well as its limitations, are described. > > To summarize what was previously said in this thread: > > * Apparently, we agree that the freezer is _generally_ not needed for suspend > (ie. any transition to a system sleep state other than hibernation), but some > of us (eg. me) think that it wouldn't be reasonable to drop the freezer from > the suspend code path _right_ _now_ . > > * Some of us, including you, Nigel and me, think that the freezer is needed > for hibernation (please see the document in the patch above for details). > In the (very) long run this might be avoided too, but (IMO) certainly not at > this point. > > * We seem to agree that in order to remove the freezer from the suspend code > path some work needs to be done on device drivers, driver midlayers and the > PM core. We also need to do some work on the PM core in order to introduce > a separate hibernation framework and IMO it would be reasonable to > synchronize these efforts. > > * We are now to decide what to do so that the freezer can be safely removed > from the suspend code path and how to integrate that change with the > hibernation code path (if possible and reasonable). Nice summary, thanks. > * The freezer vs FUSE issue that started this thread remains unresolved, so > it would be desirable to provide a short-term fix (need not be very nice). Actually there are _2_ freezer vs FUSE issues, and one of them should be simple to solve, once we have sysrq-t of the deadlock. (Or did I miss it somewhere with discussion going on 10 lists in parallel?) 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
