mm/page_alloc: cache the result of node_dirty_ok()

To spread dirty pages, nodes are checked whether they have reached the
dirty limit using the expensive node_dirty_ok().  To reduce the frequency
of calling node_dirty_ok(), the last node that hit the dirty limit can be
cached.

Instead of caching the node, caching both the node and its node_dirty_ok()
status can reduce the number of calle to node_dirty_ok().

[[email protected]: rename last_pgdat_dirty_limit to last_pgdat_dirty_ok]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Wonhyuk Yang <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Acked-by: Mel Gorman <[email protected]>
Cc: Donghyeok Kim <[email protected]>
Cc: JaeSang Yoo <[email protected]>
Cc: Jiyoup Kim <[email protected]>
Cc: Ohhoon Kwon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions