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-rw-r--r--mm/page_alloc.c33
-rw-r--r--mm/vmscan.c64
2 files changed, 92 insertions, 5 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 40169f0b7e9..3c0f69ded6b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -724,6 +724,14 @@ int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
return 1;
}
+static inline int
+should_reclaim_zone(struct zone *z, unsigned int gfp_mask)
+{
+ if (!z->reclaim_pages)
+ return 0;
+ return 1;
+}
+
/*
* This is the 'heart' of the zoned buddy allocator.
*/
@@ -760,17 +768,32 @@ __alloc_pages(unsigned int __nocast gfp_mask, unsigned int order,
classzone_idx = zone_idx(zones[0]);
- restart:
+restart:
/* Go through the zonelist once, looking for a zone with enough free */
for (i = 0; (z = zones[i]) != NULL; i++) {
-
- if (!zone_watermark_ok(z, order, z->pages_low,
- classzone_idx, 0, 0))
- continue;
+ int do_reclaim = should_reclaim_zone(z, gfp_mask);
if (!cpuset_zone_allowed(z))
continue;
+ /*
+ * If the zone is to attempt early page reclaim then this loop
+ * will try to reclaim pages and check the watermark a second
+ * time before giving up and falling back to the next zone.
+ */
+zone_reclaim_retry:
+ if (!zone_watermark_ok(z, order, z->pages_low,
+ classzone_idx, 0, 0)) {
+ if (!do_reclaim)
+ continue;
+ else {
+ zone_reclaim(z, gfp_mask, order);
+ /* Only try reclaim once */
+ do_reclaim = 0;
+ goto zone_reclaim_retry;
+ }
+ }
+
page = buffered_rmqueue(z, order, gfp_mask);
if (page)
goto got_pg;
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 6379ddbffd9..7da846960d8 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1323,3 +1323,67 @@ static int __init kswapd_init(void)
}
module_init(kswapd_init)
+
+
+/*
+ * Try to free up some pages from this zone through reclaim.
+ */
+int zone_reclaim(struct zone *zone, unsigned int gfp_mask, unsigned int order)
+{
+ struct scan_control sc;
+ int nr_pages = 1 << order;
+ int total_reclaimed = 0;
+
+ /* The reclaim may sleep, so don't do it if sleep isn't allowed */
+ if (!(gfp_mask & __GFP_WAIT))
+ return 0;
+ if (zone->all_unreclaimable)
+ return 0;
+
+ sc.gfp_mask = gfp_mask;
+ sc.may_writepage = 0;
+ sc.may_swap = 0;
+ sc.nr_mapped = read_page_state(nr_mapped);
+ sc.nr_scanned = 0;
+ sc.nr_reclaimed = 0;
+ /* scan at the highest priority */
+ sc.priority = 0;
+
+ if (nr_pages > SWAP_CLUSTER_MAX)
+ sc.swap_cluster_max = nr_pages;
+ else
+ sc.swap_cluster_max = SWAP_CLUSTER_MAX;
+
+ shrink_zone(zone, &sc);
+ total_reclaimed = sc.nr_reclaimed;
+
+ return total_reclaimed;
+}
+
+asmlinkage long sys_set_zone_reclaim(unsigned int node, unsigned int zone,
+ unsigned int state)
+{
+ struct zone *z;
+ int i;
+
+ if (node >= MAX_NUMNODES || !node_online(node))
+ return -EINVAL;
+
+ /* This will break if we ever add more zones */
+ if (!(zone & (1<<ZONE_DMA|1<<ZONE_NORMAL|1<<ZONE_HIGHMEM)))
+ return -EINVAL;
+
+ for (i = 0; i < MAX_NR_ZONES; i++) {
+ if (!(zone & 1<<i))
+ continue;
+
+ z = &NODE_DATA(node)->node_zones[i];
+
+ if (state)
+ z->reclaim_pages = 1;
+ else
+ z->reclaim_pages = 0;
+ }
+
+ return 0;
+}