mm/sparse.c: introduce a new function clear_subsection_map()

Factor out the code which clear subsection map of one memory region from
section_deactivate() into clear_subsection_map().

And also add helper function is_subsection_map_empty() to check if the
current subsection map is empty or not.

Signed-off-by: Baoquan He <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Acked-by: Pankaj Gupta <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Wei Yang <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions