On Wed 2009-12-02 22:07:18, Mel Gorman wrote: > On Wed, Dec 02, 2009 at 10:11:07PM +0100, Pavel Machek wrote: > > On Wed 2009-12-02 14:28:12, Alan Jenkins wrote: > > > The original in-kernel suspend (swsusp) frees the in-memory hibernation > > > image before powering off the machine. s2disk doesn't, so there is > > > _much_ less free memory when it tries to power off. > > > > > > This is a gratuitous difference. The userspace suspend interface > > > /dev/snapshot only allows the hibernation image to be read once. > > > Once the s2disk program has read the last page, we can free the entire > > > image. > > > > > > This avoids a hang after writing the hibernation image which was > > > triggered by commit 5f8dcc21211a3d4e3a7a5ca366b469fb88117f61 > > > "page-allocator: split per-cpu list into one-list-per-migrate-type": > > > > Yes, you work around page-allocator hang. But is it right thing to do? > > > > What's wrong with it? The hang is likely because the allocator has no > memory to work with. The patch in question makes small changes to the > amount of available memory but it shouldn't matter on uni-core. Some > structures are slightly larger but it's extremely borderline. I'm at a > loss to explain actually why it makes a difference untill things were > extremely borderline to begin with. We reserve 4MB, for such purposes, and we already wrote image to disk with such constrains, so memory should not be _too_ tight. Can you try increasing PAGES_FOR_IO to 8MB or something like that? 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
