On Wed, Jul 24, 2019 at 04:26:58PM -0700, Ralph Campbell wrote: > Struct page for ZONE_DEVICE private pages uses the page->mapping and > and page->index fields while the source anonymous pages are migrated to > device private memory. This is so rmap_walk() can find the page when > migrating the ZONE_DEVICE private page back to system memory. > ZONE_DEVICE pmem backed fsdax pages also use the page->mapping and > page->index fields when files are mapped into a process address space. > > Add comments to struct page and remove the unused "_zd_pad_1" field > to make this more clear. > > Signed-off-by: Ralph Campbell <rcampbell@xxxxxxxxxx> > Reviewed-by: John Hubbard <jhubbard@xxxxxxxxxx> > Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> > Cc: Vlastimil Babka <vbabka@xxxxxxx> > Cc: Christoph Lameter <cl@xxxxxxxxx> > Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> > Cc: Jérôme Glisse <jglisse@xxxxxxxxxx> > Cc: "Kirill A . Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> > Cc: Lai Jiangshan <jiangshanlai@xxxxxxxxx> > Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> > Cc: Pekka Enberg <penberg@xxxxxxxxxx> > Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> > Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> > Cc: Christoph Hellwig <hch@xxxxxx> > Cc: Jason Gunthorpe <jgg@xxxxxxxxxxxx> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > include/linux/mm_types.h | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) Ralph, you marked some of thes patches as mm/hmm, but I feel it is best if Andrew takes them through the normal -mm path. They don't touch hmm.c or mmu notifiers so I don't forsee conflicts, and I don't feel comfortable to review this code. Regards, Jason
