Commit 1da58ee2 authored Dec 10, 2014 by Jamie Liu Committed by Linus Torvalds Dec 10, 2014

mm: vmscan: count only dirty pages as congested



shrink_page_list() counts all pages with a mapping, including clean pages,
toward nr_congested if they're on a write-congested BDI.
shrink_inactive_list() then sets ZONE_CONGESTED if nr_dirty ==
nr_congested.  Fix this apples-to-oranges comparison by only counting
pages for nr_congested if they count for nr_dirty.

Signed-off-by: Jamie Liu <jamieliu@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Greg Thelen <gthelen@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent ab1f306f

mm/vmscan.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -874,7 +874,8 @@ static unsigned long shrink_page_list(struct list_head *page_list,
		* end of the LRU a second time.
		*/
		mapping = page_mapping(page);
		if ((mapping && bdi_write_congested(mapping->backing_dev_info)) \|\|
		if (((dirty \|\| writeback) && mapping &&
		bdi_write_congested(mapping->backing_dev_info)) \|\|
		(writeback && PageReclaim(page)))
		nr_congested++;

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