mm: page allocator: adjust the per-cpu counter threshold when memory is low

[pandora-kernel.git] / mm / page_alloc.c

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 826ba69..22a1bb7 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1460,24 +1460,24 @@ static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
 #endif /* CONFIG_FAIL_PAGE_ALLOC */
 
 /*
- * Return 1 if free pages are above 'mark'. This takes into account the order
+ * Return true if free pages are above 'mark'. This takes into account the order
  * of the allocation.
  */
-int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
-                     int classzone_idx, int alloc_flags)
+static bool __zone_watermark_ok(struct zone *z, int order, unsigned long mark,
+                     int classzone_idx, int alloc_flags, long free_pages)
 {
        /* free_pages my go negative - that's OK */
        long min = mark;
-       long free_pages = zone_nr_free_pages(z) - (1 << order) + 1;
        int o;
 
+       free_pages -= (1 << order) + 1;
        if (alloc_flags & ALLOC_HIGH)
                min -= min / 2;
        if (alloc_flags & ALLOC_HARDER)
                min -= min / 4;
 
        if (free_pages <= min + z->lowmem_reserve[classzone_idx])
-               return 0;
+               return false;
        for (o = 0; o < order; o++) {
                /* At the next order, this order's pages become unavailable */
                free_pages -= z->free_area[o].nr_free << o;
@@ -1486,9 +1486,28 @@ int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
                min >>= 1;
 
                if (free_pages <= min)
-                       return 0;
+                       return false;
        }
-       return 1;
+       return true;
+}
+
+bool zone_watermark_ok(struct zone *z, int order, unsigned long mark,
+                     int classzone_idx, int alloc_flags)
+{
+       return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
+                                       zone_page_state(z, NR_FREE_PAGES));
+}
+
+bool zone_watermark_ok_safe(struct zone *z, int order, unsigned long mark,
+                     int classzone_idx, int alloc_flags)
+{
+       long free_pages = zone_page_state(z, NR_FREE_PAGES);
+
+       if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
+               free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
+
+       return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
+                                                               free_pages);
 }
 
 #ifdef CONFIG_NUMA
@@ -2442,7 +2461,7 @@ void show_free_areas(void)
                        " all_unreclaimable? %s"
                        "\n",
                        zone->name,
-                       K(zone_nr_free_pages(zone)),
+                       K(zone_page_state(zone, NR_FREE_PAGES)),
                        K(min_wmark_pages(zone)),
                        K(low_wmark_pages(zone)),
                        K(high_wmark_pages(zone)),