mm: vmscan: do not stall on writeback during memory compaction

This patch stops reclaim/compaction entering sync reclaim as this was
only intended for lumpy reclaim and an oversight.  Page migration has
its own logic for stalling on writeback pages if necessary and memory
compaction is already using it.

Waiting on page writeback is bad for a number of reasons but the primary
one is that waiting on writeback to a slow device like USB can take a
considerable length of time.  Page reclaim instead uses
wait_iff_congested() to throttle if too many dirty pages are being
scanned.

Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Rik van Riel <[email protected]>
Acked-by: KOSAKI Motohiro <[email protected]>
Cc: Konstantin Khlebnikov <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Ying Han <[email protected]>
Cc: Andy Whitcroft <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions