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-rw-r--r--mm/page_alloc.c27
1 files changed, 14 insertions, 13 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 845b91749a4..3c5cf664abd 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2397,13 +2397,18 @@ void setup_per_zone_pages_min(void)
}
for_each_zone(zone) {
+ unsigned long tmp;
spin_lock_irqsave(&zone->lru_lock, flags);
+ tmp = (pages_min * zone->present_pages) / lowmem_pages;
if (is_highmem(zone)) {
/*
- * Often, highmem doesn't need to reserve any pages.
- * But the pages_min/low/high values are also used for
- * batching up page reclaim activity so we need a
- * decent value here.
+ * __GFP_HIGH and PF_MEMALLOC allocations usually don't
+ * need highmem pages, so cap pages_min to a small
+ * value here.
+ *
+ * The (pages_high-pages_low) and (pages_low-pages_min)
+ * deltas controls asynch page reclaim, and so should
+ * not be capped for highmem.
*/
int min_pages;
@@ -2414,19 +2419,15 @@ void setup_per_zone_pages_min(void)
min_pages = 128;
zone->pages_min = min_pages;
} else {
- /* if it's a lowmem zone, reserve a number of pages
+ /*
+ * If it's a lowmem zone, reserve a number of pages
* proportionate to the zone's size.
*/
- zone->pages_min = (pages_min * zone->present_pages) /
- lowmem_pages;
+ zone->pages_min = tmp;
}
- /*
- * When interpreting these watermarks, just keep in mind that:
- * zone->pages_min == (zone->pages_min * 4) / 4;
- */
- zone->pages_low = (zone->pages_min * 5) / 4;
- zone->pages_high = (zone->pages_min * 6) / 4;
+ zone->pages_low = zone->pages_min + tmp / 4;
+ zone->pages_high = zone->pages_min + tmp / 2;
spin_unlock_irqrestore(&zone->lru_lock, flags);
}
}