diff options
| -rw-r--r-- | include/linux/mmzone.h | 1 | ||||
| -rw-r--r-- | mm/page_alloc.c | 19 | ||||
| -rw-r--r-- | mm/vmscan.c | 35 |
3 files changed, 54 insertions, 1 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 0a86b2890a16..b2f40d64bc4b 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -647,6 +647,7 @@ enum zone_flags { ZONE_BOOSTED_WATERMARK, /* zone recently boosted watermarks. * Cleared when kswapd is woken. */ + ZONE_RECLAIM_ACTIVE, /* kswapd may be scanning the zone. */ }; static inline unsigned long zone_managed_pages(struct zone *zone) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index e1d1825a2611..adf35ccfd8e5 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3302,6 +3302,23 @@ static int nr_pcp_free(struct per_cpu_pages *pcp, int high, int batch) return batch; } +static int nr_pcp_high(struct per_cpu_pages *pcp, struct zone *zone) +{ + int high = READ_ONCE(pcp->high); + + if (unlikely(!high)) + return 0; + + if (!test_bit(ZONE_RECLAIM_ACTIVE, &zone->flags)) + return high; + + /* + * If reclaim is active, limit the number of pages that can be + * stored on pcp lists + */ + return min(READ_ONCE(pcp->batch) << 2, high); +} + static void free_unref_page_commit(struct page *page, unsigned long pfn, int migratetype) { @@ -3313,7 +3330,7 @@ static void free_unref_page_commit(struct page *page, unsigned long pfn, pcp = this_cpu_ptr(zone->per_cpu_pageset); list_add(&page->lru, &pcp->lists[migratetype]); pcp->count++; - high = READ_ONCE(pcp->high); + high = nr_pcp_high(pcp, zone); if (pcp->count >= high) { int batch = READ_ONCE(pcp->batch); diff --git a/mm/vmscan.c b/mm/vmscan.c index f96d62159720..d7c3cb8688dd 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3722,6 +3722,38 @@ static bool kswapd_shrink_node(pg_data_t *pgdat, return sc->nr_scanned >= sc->nr_to_reclaim; } +/* Page allocator PCP high watermark is lowered if reclaim is active. */ +static inline void +update_reclaim_active(pg_data_t *pgdat, int highest_zoneidx, bool active) +{ + int i; + struct zone *zone; + + for (i = 0; i <= highest_zoneidx; i++) { + zone = pgdat->node_zones + i; + + if (!managed_zone(zone)) + continue; + + if (active) + set_bit(ZONE_RECLAIM_ACTIVE, &zone->flags); + else + clear_bit(ZONE_RECLAIM_ACTIVE, &zone->flags); + } +} + +static inline void +set_reclaim_active(pg_data_t *pgdat, int highest_zoneidx) +{ + update_reclaim_active(pgdat, highest_zoneidx, true); +} + +static inline void +clear_reclaim_active(pg_data_t *pgdat, int highest_zoneidx) +{ + update_reclaim_active(pgdat, highest_zoneidx, false); +} + /* * For kswapd, balance_pgdat() will reclaim pages across a node from zones * that are eligible for use by the caller until at least one zone is @@ -3774,6 +3806,7 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int highest_zoneidx) boosted = nr_boost_reclaim; restart: + set_reclaim_active(pgdat, highest_zoneidx); sc.priority = DEF_PRIORITY; do { unsigned long nr_reclaimed = sc.nr_reclaimed; @@ -3907,6 +3940,8 @@ restart: pgdat->kswapd_failures++; out: + clear_reclaim_active(pgdat, highest_zoneidx); + /* If reclaim was boosted, account for the reclaim done in this pass */ if (boosted) { unsigned long flags; |