diff options
author | Ralph Campbell <rcampbell@nvidia.com> | 2019-08-13 15:37:04 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-08-13 16:06:52 -0700 |
commit | 76470ccd62f18bfa0954bec10f2329339f793914 (patch) | |
tree | 72d5ecefb991a588c39bf47eca9ad178337ff459 /mm/rmap.c | |
parent | d45331b00ddb179e291766617259261c112db872 (diff) | |
download | linux-76470ccd62f18bfa0954bec10f2329339f793914.tar.gz linux-76470ccd62f18bfa0954bec10f2329339f793914.tar.bz2 linux-76470ccd62f18bfa0954bec10f2329339f793914.zip |
mm: document zone device struct page field usage
Patch series "mm/hmm: fixes for device private page migration", v3.
Testing the latest linux git tree turned up a few bugs with page
migration to and from ZONE_DEVICE private and anonymous pages.
Hopefully it clarifies how ZONE_DEVICE private struct page uses the same
mapping and index fields from the source anonymous page mapping.
This patch (of 3):
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.
Link: http://lkml.kernel.org/r/20190724232700.23327-2-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/rmap.c')
0 files changed, 0 insertions, 0 deletions