On Mon 06-11-17 19:36:38, Maxim Levitsky wrote: > Isn't this a non backward compatible change? Why to remove an optional non > default option for use cases like mine. Well, strictly speaking it is. The reality is that with the current implementation the option breaks the hotplug usecase. I can see your argument about the opt in and we might need to hold on this patch for merging uut it seems that http://lkml.kernel.org/r/20171003072619.8654-1-mhocko@xxxxxxxxxx is not the problem you are seeing. > I won't argue with you on this, but my question was different, and was why > the kernel can't move other pages from moveable zone in my case. OK, I have re-read your original report where you say : This was tested on 4.14.0-rc5 (my custom compiled) and on several : older kernels (4.10,4.12,4.13) from ubuntu repositories. Does that mean that this a new regression in 4.14-rc5 or you see the problem in other kernels too? If this a new rc5 thing then 79b63f12abcb ("mm, hugetlb: do not allocate non-migrateable gigantic pages from movable zones") might be related. Although it shouldn't if hugepages_treat_as_movable is enabled. I wouldn't be all that surprised if this was an older issue, though. If I look at pfn_range_valid_gigantic it seems that the page count check makes it just too easy to fail even on migratable memory. To be honest I consider the giga pages runtime support rather fragile and that is why I wasn't very much afraid to remove hacks that allow breaking other usecases. -- 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>
