diff --git a/mm/vmscan.c b/mm/vmscan.c index 2f45c0520f43fb..8ad39bbc79e67e 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1449,7 +1449,7 @@ static __always_inline void update_lru_sizes(struct lruvec *lruvec, * * Appropriate locks must be held before calling this function. * - * @nr_to_scan: The number of pages to look through on the list. + * @nr_to_scan: The number of eligible pages to look through on the list. * @lruvec: The LRU vector to pull pages from. * @dst: The temp list to put pages on to. * @nr_scanned: The number of pages that were scanned. @@ -1469,11 +1469,13 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan, unsigned long nr_zone_taken[MAX_NR_ZONES] = { 0 }; unsigned long nr_skipped[MAX_NR_ZONES] = { 0, }; unsigned long skipped = 0; - unsigned long scan, nr_pages; + unsigned long scan, total_scan, nr_pages; LIST_HEAD(pages_skipped); - for (scan = 0; scan < nr_to_scan && nr_taken < nr_to_scan && - !list_empty(src); scan++) { + scan = 0; + for (total_scan = 0; + scan < nr_to_scan && nr_taken < nr_to_scan && !list_empty(src); + total_scan++) { struct page *page; page = lru_to_page(src); @@ -1487,6 +1489,13 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan, continue; } + /* + * Do not count skipped pages because that makes the function + * return with no isolated pages if the LRU mostly contains + * ineligible pages. This causes the VM to not reclaim any + * pages, triggering a premature OOM. + */ + scan++; switch (__isolate_lru_page(page, mode)) { case 0: nr_pages = hpage_nr_pages(page); @@ -1524,9 +1533,9 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan, skipped += nr_skipped[zid]; } } - *nr_scanned = scan; + *nr_scanned = total_scan; trace_mm_vmscan_lru_isolate(sc->reclaim_idx, sc->order, nr_to_scan, - scan, skipped, nr_taken, mode, lru); + total_scan, skipped, nr_taken, mode, lru); update_lru_sizes(lruvec, lru, nr_zone_taken); return nr_taken; }