diff options
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 4c847cc57ca..33b1a4762a7 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2836,7 +2836,8 @@ static void setup_zone_migrate_reserve(struct zone *zone) { unsigned long start_pfn, pfn, end_pfn; struct page *page; - unsigned long reserve, block_migratetype; + unsigned long block_migratetype; + int reserve; /* Get the start pfn, end pfn and the number of blocks to reserve */ start_pfn = zone->zone_start_pfn; @@ -2844,6 +2845,15 @@ static void setup_zone_migrate_reserve(struct zone *zone) reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >> pageblock_order; + /* + * Reserve blocks are generally in place to help high-order atomic + * allocations that are short-lived. A min_free_kbytes value that + * would result in more than 2 reserve blocks for atomic allocations + * is assumed to be in place to help anti-fragmentation for the + * future allocation of hugepages at runtime. + */ + reserve = min(2, reserve); + for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) { if (!pfn_valid(pfn)) continue; |