diff options
| -rw-r--r-- | mm/vmscan.c | 27 |
1 files changed, 15 insertions, 12 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index 7889f583ced9..910e02c793ff 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3644,19 +3644,18 @@ out: } /* - * pgdat->kswapd_classzone_idx is the highest zone index that a recent - * allocation request woke kswapd for. When kswapd has not woken recently, - * the value is MAX_NR_ZONES which is not a valid index. This compares a - * given classzone and returns it or the highest classzone index kswapd - * was recently woke for. + * The pgdat->kswapd_classzone_idx is used to pass the highest zone index to be + * reclaimed by kswapd from the waker. If the value is MAX_NR_ZONES which is not + * a valid index then either kswapd runs for first time or kswapd couldn't sleep + * after previous reclaim attempt (node is still unbalanced). In that case + * return the zone index of the previous kswapd reclaim cycle. */ static enum zone_type kswapd_classzone_idx(pg_data_t *pgdat, - enum zone_type classzone_idx) + enum zone_type prev_classzone_idx) { if (pgdat->kswapd_classzone_idx == MAX_NR_ZONES) - return classzone_idx; - - return max(pgdat->kswapd_classzone_idx, classzone_idx); + return prev_classzone_idx; + return pgdat->kswapd_classzone_idx; } static void kswapd_try_to_sleep(pg_data_t *pgdat, int alloc_order, int reclaim_order, @@ -3797,7 +3796,7 @@ kswapd_try_sleep: /* Read the new order and classzone_idx */ alloc_order = reclaim_order = pgdat->kswapd_order; - classzone_idx = kswapd_classzone_idx(pgdat, 0); + classzone_idx = kswapd_classzone_idx(pgdat, classzone_idx); pgdat->kswapd_order = 0; pgdat->kswapd_classzone_idx = MAX_NR_ZONES; @@ -3851,8 +3850,12 @@ void wakeup_kswapd(struct zone *zone, gfp_t gfp_flags, int order, if (!cpuset_zone_allowed(zone, gfp_flags)) return; pgdat = zone->zone_pgdat; - pgdat->kswapd_classzone_idx = kswapd_classzone_idx(pgdat, - classzone_idx); + + if (pgdat->kswapd_classzone_idx == MAX_NR_ZONES) + pgdat->kswapd_classzone_idx = classzone_idx; + else + pgdat->kswapd_classzone_idx = max(pgdat->kswapd_classzone_idx, + classzone_idx); pgdat->kswapd_order = max(pgdat->kswapd_order, order); if (!waitqueue_active(&pgdat->kswapd_wait)) return; |