mm/compaction: Disable compact_unevictable_allowed on RT

Since commit 5bbe3547aa3ba ("mm: allow compaction of unevictable pages")
it is allowed to examine mlocked pages and compact them by default.  On
-RT even minor pagefaults are problematic because it may take a few 100us
to resolve them and until then the task is blocked.

Make compact_unevictable_allowed = 0 default and issue a warning on RT if
it is changed.

[[email protected]: v5]
  Link: https://lore.kernel.org/linux-mm/[email protected]/
  Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Sebastian Andrzej Siewior <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Reviewed-by: Andrew Morton <[email protected]>
Acked-by: Mel Gorman <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Luis Chamberlain <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Iurii Zaikin <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Link: https://lore.kernel.org/linux-mm/[email protected]/
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions