On Fri 14-01-22 18:03:04, Xiongwei Song wrote: > HI Michal, > > On Thu, Jan 13, 2022 at 11:31 PM Michal Hocko <mhocko@xxxxxxxx> wrote: > > > > On Wed 12-01-22 22:35:17, sxwjean@xxxxxx wrote: > > > From: Xiongwei Song <sxwjean@xxxxxxxxx> > > > > > > When requesting pages info by /proc/kpage*, the pages in ZONE_DEVICE were > > > ignored. > > > > > > The pfn_to_devmap_page() function can help to get page that belongs to > > > ZONE_DEVICE. > > > > Why is this needed? Who would consume that information and what for? > > It's for debug purpose, which checks page flags in system wide. No any other > special thought. But it looks like it's not appropriate to expose now from my > understand, which is from David's comment. > https://lore.kernel.org/linux-mm/20220110141957.259022-1-sxwjean@xxxxxx/T/#m4eccbb2698dbebc80ec00be47382b34b0f64b4fc yes, I do agree with David. This is the reason I am asking because I do remember we have deliberately excluded those pages. If there is no real user to use that information then I do not think we want to make the code more complex and check for memmap and other peculiarities. Thanks! -- Michal Hocko SUSE Labs
