*
* 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.
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);
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);
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;
}