diff options
Diffstat (limited to 'mm/swap.c')
| -rw-r--r-- | mm/swap.c | 32 |
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, |