mm: convert "movable" flag in page->mapping to a page flag

Instead, let's use a page flag.  As the page flag can result in
false-positives, glue it to the page types for which we support/implement
movable_ops page migration.

We are reusing PG_uptodate, that is for example used to track file system
state and does not apply to movable_ops pages.  So warning in case it is
set in page_has_movable_ops() on other page types could result in
false-positive warnings.

Likely we could set the bit using a non-atomic update: in contrast to
page->mapping, we could have others trying to update the flags
concurrently when trying to lock the folio.  In
isolate_movable_ops_page(), we already take care of that by checking if
the page has movable_ops before locking it.  Let's start with the atomic
variant, we could later switch to the non-atomic variant once we are sure
other cases are similarly fine.  Once we perform the switch, we'll have to
introduce __SETPAGEFLAG_NOOP().

[[email protected]: add missing `:' in kerneldoc]
  Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Reviewed-by: Zi Yan <[email protected]>
Reviewed-by: Lorenzo Stoakes <[email protected]>
Cc: Alistair Popple <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Brendan Jackman <[email protected]>
Cc: Byungchul Park <[email protected]>
Cc: Chengming Zhou <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Eugenio Pé rez <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Gregory Price <[email protected]>
Cc: Harry Yoo <[email protected]>
Cc: "Huang, Ying" <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Jason Wang <[email protected]>
Cc: Jerrin Shaji George <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: John Hubbard <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Joshua Hahn <[email protected]>
Cc: Liam Howlett <[email protected]>
Cc: Madhavan Srinivasan <[email protected]>
Cc: Mathew Brost <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Miaohe Lin <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: "Michael S. Tsirkin" <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Qi Zheng <[email protected]>
Cc: Rakie Kim <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Sergey Senozhatsky <[email protected]>
Cc: Shakeel Butt <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Xuan Zhuo <[email protected]>
Cc: xu xin <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions