On 2019/11/08 18:18, Michal Hocko wrote: > On Fri 08-11-19 00:08:03, Toshiki Fukasawa wrote: >> This patch set tries to make pfn walker support ZONE_DEVICE. >> This idea is from the TODO in below patch: >> >> commit aad5f69bc161af489dbb5934868bd347282f0764 >> Author: David Hildenbrand <david@xxxxxxxxxx> >> Date: Fri Oct 18 20:19:20 2019 -0700 >> >> fs/proc/page.c: don't access uninitialized memmaps in fs/proc/page.c >> >> pfn walker's ZONE_DEVICE support requires capability to identify >> that a memmap has been initialized. The uninitialized cases are >> as follows: >> >> a) pages reserved for ZONE_DEVICE driver >> b) pages currently initializing >> >> This patch set solves both of them. > > Why do we want this? What is the usecase? We are writing a test program for hwpoison, which is a use case. Without this patch, we can't see the HWPOISON flag on the ZONE_DEVICE page. Thanks, Toshiki Fukasawa
