Michal Hocko <mhocko@xxxxxxxxxx> writes: > From: Michal Hocko <mhocko@xxxxxxxx> > > Michael has noticed that the memory offline tries to migrate kernel code > pages when doing > echo 0 > /sys/devices/system/memory/memory0/online > > The current implementation will fail the operation after several failed > page migration attempts but we shouldn't even attempt to migrate > that memory and fail right away because this memory is clearly not > migrateable. This will become a real problem when we drop the retry loop > counter resp. timeout. > > The real problem is in has_unmovable_pages in fact. We should fail if > there are any non migrateable pages in the area. In orther to guarantee > that remove the migrate type checks because MIGRATE_MOVABLE is not > guaranteed to contain only migrateable pages. It is merely a heuristic. > Similarly MIGRATE_CMA does guarantee that the page allocator doesn't > allocate any non-migrateable pages from the block but CMA allocations > themselves are unlikely to migrateable. Therefore remove both checks. > > Reported-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> > Signed-off-by: Michal Hocko <mhocko@xxxxxxxx> Thanks, that works for me. Tested-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> cheers -- 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>
