mm: vmscan: have kswapd writeback pages based on dirty pages encountered, not priority

Currently kswapd queues dirty pages for writeback if scanning at an
elevated priority but the priority kswapd scans at is not related to the
number of unqueued dirty encountered.  Since commit "mm: vmscan: Flatten
kswapd priority loop", the priority is related to the size of the LRU
and the zone watermark which is no indication as to whether kswapd
should write pages or not.

This patch tracks if an excessive number of unqueued dirty pages are
being encountered at the end of the LRU.  If so, it indicates that dirty
pages are being recycled before flusher threads can clean them and flags
the zone so that kswapd will start writing pages until the zone is
balanced.

Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Reviewed-by: Michal Hocko <[email protected]>
Cc: KAMEZAWA Hiroyuki <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: Valdis Kletnieks <[email protected]>
Tested-by: Zlatko Calusic <[email protected]>
Cc: dormando <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions