Page reclaim determines whether a pgdat is unreclaimable by examining how
many pages have been scanned since a page was freed and comparing that
to the LRU sizes. Skipped pages are not considered reclaim candidates but
contribute to scanned. This can prematurely mark a pgdat as unreclaimable
and trigger an OOM kill.
While this does not fix an OOM kill message reported by Joonsoo Kim,
it did stop pgdat being marked unreclaimable.
Signed-off-by: Mel Gorman <mgor...@techsingularity.net>
---
mm/vmscan.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 22aec2bcfeec..b16d578ce556 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1415,7 +1415,7 @@ static unsigned long isolate_lru_pages(unsigned long
nr_to_scan,
LIST_HEAD(pages_skipped);
for (scan = 0; scan < nr_to_scan && nr_taken < nr_to_scan &&
- !list_empty(src); scan++) {
+ !list_empty(src);) {
struct page *page;
page = lru_to_page(src);
@@ -1429,6 +1429,9 @@ static unsigned long isolate_lru_pages(unsigned long
nr_to_scan,
continue;
}
+ /* Pages skipped do not contribute to scan */
+ scan++;
+
switch (__isolate_lru_page(page, mode)) {
case 0:
nr_pages = hpage_nr_pages(page);
--
2.6.4
