On Thu 2009-05-14 19:49:52, Rafael J. Wysocki wrote: > On Thursday 14 May 2009, Pavel Machek wrote: > > > > > > > > The main point (I thought) was to remove shrink_all_memory(). Instead, > > > > > > we're retaining it and adding even more stuff? > > > > > > > > > > The idea is that afterwards we can drop shrink_all_memory() once the > > > > > performance problem has been resolved. Also, we now allocate memory for the > > > > > image using GFP_KERNEL instead of doing it with GFP_ATOMIC after freezing > > > > > devices. I'd think that's an improvement? > > > > > > > > Dunno. GFP_KERNEL might attempt to do writeback/swapout/etc, which > > > > could be embarrassing if the devices are frozen. > > > > > > They aren't, because the preallocation is done upfront, so once the OOM killer > > > has been taken care of, it's totally safe. :-) > > > > As is GFP_ATOMIC. Except that GFP_KERNEL will cause catastrophic > > consequences when accounting goes wrong. (New kernel's idea of what is > > on disk will differ from what is _really_ on disk.) > > > > If accounting is right, GFP_ATOMIC and GFP_KERNEL is equivalent. > > > > If accounting is wrong, GFP_ATOMIC will fail with NULL, while > > GFP_KERNEL will do something bad. > > > > I'd keep GFP_ATOMIC (or GFP_NOIO or similar). > > Repeating myself: with this and the next patch applied, we preallocate memory > for the image _before_ freezing devices and therefore it is safe to use > GFP_KERNEL, because the OOM killer has been taken care of by [3/6]. Aha, I misparsed the sentecnes above. Acked-by: Pavel Machek <pavel@xxxxxx> 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
