On Mon 06-11-17 20:13:36, Maxim Levitsky wrote: > Yes, I tested git head from mainline and few kernels from ubuntu repos > since I was lazy to compile them too. OK, so this hasn't worked realiably as I've suspected. > Do you have an idea what can I do about this issue? Do you think its > feasable to fix this? Well, I think that giga pages need quite some love to be usable reliably. The current implementation is more towards "make it work if there is enough unused memory". > And if not using moveable zone, how would it even be possible to have > guaranreed allocation of 1g pages Having a guaranteed giga pages is something the kernel is not yet ready to offer. Abusing zone movable might look like the right direction but that is not really the case until we make sure those pages are migratable. There has been a simple patch which makes PUD (1GB) pages migrateable http://lkml.kernel.org/r/20170913101047.GA13026@xxxxxxxxx but I've had concerns that it really didn't consider the migration path much http://lkml.kernel.org/r/20171003073301.hydw7jf2wztsx2om%40dhcp22.suse.cz I still believe the patch is not complete but maybe it is not that far away from being so. E.g. the said pfn_range_valid_gigantic can be enhanced to make the migration much more reliable or get rid of it altogether because the pfn based allocator already knows how to do migration and other stuff. I can help some with that. -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
