On Fri, Jun 30, 2017 at 04:19:25PM -0700, Evgeny Baskakov wrote: > Hi Jerome, > > It seems that the kernel can pass 0 in src_pfns for pages that it cannot > migrate (i.e. the kernel knows that they cannot migrate prior to calling > alloc_and_copy). > > So, a zero in src_pfns can mean either "the page is not allocated yet" or > "the page cannot migrate". > > Can migrate_vma set the MIGRATE_PFN_MIGRATE flag for not allocated pages? On > the driver side it is difficult to differentiate between the cases. So this is what is happening in v24. For thing that can not be migrated you get 0 and for things that are not allocated you get MIGRATE_PFN_MIGRATE like the updated comments in migrate.h explain. Cheers, Jérôme -- 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>
