diff options
| -rw-r--r-- | mm/vmscan.c | 80 |
1 files changed, 42 insertions, 38 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index 39589e561c8f..725b5d4784f7 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -101,6 +101,9 @@ struct scan_control { /* One of the zones is ready for compaction */ unsigned int compaction_ready:1; + /* The file pages on the current node are dangerously low */ + unsigned int file_is_tiny:1; + /* Allocation order */ s8 order; @@ -2289,45 +2292,16 @@ static void get_scan_count(struct lruvec *lruvec, struct scan_control *sc, } /* - * Prevent the reclaimer from falling into the cache trap: as - * cache pages start out inactive, every cache fault will tip - * the scan balance towards the file LRU. And as the file LRU - * shrinks, so does the window for rotation from references. - * This means we have a runaway feedback loop where a tiny - * thrashing file LRU becomes infinitely more attractive than - * anon pages. Try to detect this based on file LRU size. + * If the system is almost out of file pages, force-scan anon. + * But only if there are enough inactive anonymous pages on + * the LRU. Otherwise, the small LRU gets thrashed. */ - if (!cgroup_reclaim(sc)) { - unsigned long pgdatfile; - unsigned long pgdatfree; - int z; - unsigned long total_high_wmark = 0; - - pgdatfree = sum_zone_node_page_state(pgdat->node_id, NR_FREE_PAGES); - pgdatfile = node_page_state(pgdat, NR_ACTIVE_FILE) + - node_page_state(pgdat, NR_INACTIVE_FILE); - - for (z = 0; z < MAX_NR_ZONES; z++) { - struct zone *zone = &pgdat->node_zones[z]; - if (!managed_zone(zone)) - continue; - - total_high_wmark += high_wmark_pages(zone); - } - - if (unlikely(pgdatfile + pgdatfree <= total_high_wmark)) { - /* - * Force SCAN_ANON if there are enough inactive - * anonymous pages on the LRU in eligible zones. - * Otherwise, the small LRU gets thrashed. - */ - if (!inactive_list_is_low(lruvec, false, sc, false) && - lruvec_lru_size(lruvec, LRU_INACTIVE_ANON, sc->reclaim_idx) - >> sc->priority) { - scan_balance = SCAN_ANON; - goto out; - } - } + if (sc->file_is_tiny && + !inactive_list_is_low(lruvec, false, sc, false) && + lruvec_lru_size(lruvec, LRU_INACTIVE_ANON, + sc->reclaim_idx) >> sc->priority) { + scan_balance = SCAN_ANON; + goto out; } /* @@ -2754,6 +2728,36 @@ again: nr_reclaimed = sc->nr_reclaimed; nr_scanned = sc->nr_scanned; + /* + * Prevent the reclaimer from falling into the cache trap: as + * cache pages start out inactive, every cache fault will tip + * the scan balance towards the file LRU. And as the file LRU + * shrinks, so does the window for rotation from references. + * This means we have a runaway feedback loop where a tiny + * thrashing file LRU becomes infinitely more attractive than + * anon pages. Try to detect this based on file LRU size. + */ + if (!cgroup_reclaim(sc)) { + unsigned long file; + unsigned long free; + int z; + unsigned long total_high_wmark = 0; + + free = sum_zone_node_page_state(pgdat->node_id, NR_FREE_PAGES); + file = node_page_state(pgdat, NR_ACTIVE_FILE) + + node_page_state(pgdat, NR_INACTIVE_FILE); + + for (z = 0; z < MAX_NR_ZONES; z++) { + struct zone *zone = &pgdat->node_zones[z]; + if (!managed_zone(zone)) + continue; + + total_high_wmark += high_wmark_pages(zone); + } + + sc->file_is_tiny = file + free <= total_high_wmark; + } + shrink_node_memcgs(pgdat, sc); if (reclaim_state) { |