summaryrefslogtreecommitdiff
path: root/mm/swap.c
diff options
context:
space:
mode:
Diffstat (limited to 'mm/swap.c')
-rw-r--r--mm/swap.c32
1 files changed, 27 insertions, 5 deletions
diff --git a/mm/swap.c b/mm/swap.c
index 2dc7d392642f..4dff2123f695 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -282,11 +282,33 @@ void lru_note_cost(struct page *page)
{
struct lruvec *lruvec = mem_cgroup_page_lruvec(page, page_pgdat(page));
- /* Record new data point */
- if (page_is_file_lru(page))
- lruvec->file_cost++;
- else
- lruvec->anon_cost++;
+ do {
+ unsigned long lrusize;
+
+ /* Record cost event */
+ if (page_is_file_lru(page))
+ lruvec->file_cost++;
+ else
+ lruvec->anon_cost++;
+
+ /*
+ * Decay previous events
+ *
+ * Because workloads change over time (and to avoid
+ * overflow) we keep these statistics as a floating
+ * average, which ends up weighing recent refaults
+ * more than old ones.
+ */
+ lrusize = lruvec_page_state(lruvec, NR_INACTIVE_ANON) +
+ lruvec_page_state(lruvec, NR_ACTIVE_ANON) +
+ lruvec_page_state(lruvec, NR_INACTIVE_FILE) +
+ lruvec_page_state(lruvec, NR_ACTIVE_FILE);
+
+ if (lruvec->file_cost + lruvec->anon_cost > lrusize / 4) {
+ lruvec->file_cost /= 2;
+ lruvec->anon_cost /= 2;
+ }
+ } while ((lruvec = parent_lruvec(lruvec)));
}
static void __activate_page(struct page *page, struct lruvec *lruvec,