3 files changed, 29 insertions, 0 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 9a72cc78e6b8..d3c8ae7c8015 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1058,6 +1058,8 @@ extern void setup_per_cpu_pageset(void);
 static inline void setup_per_cpu_pageset(void) {}
 #endif
 
+extern void zone_pcp_update(struct zone *zone);
+
 /* nommu.c */
 extern atomic_long_t mmap_pages_allocated;
 
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index e4412a676c88..616236e6343f 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -422,6 +422,7 @@ int online_pages(unsigned long pfn, unsigned long nr_pages)
         zone->present_pages += onlined_pages;
         zone->zone_pgdat->node_present_pages += onlined_pages;
 
+        zone_pcp_update(zone);
         setup_per_zone_wmarks();
         calculate_zone_inactive_ratio(zone);
         if (onlined_pages) {
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index f4e929e356db..1a3a893ef50e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3142,6 +3142,32 @@ int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
         return 0;
 }
 
+static int __zone_pcp_update(void *data)
+{
+        struct zone *zone = data;
+        int cpu;
+        unsigned long batch = zone_batchsize(zone), flags;
+
+        for (cpu = 0; cpu < NR_CPUS; cpu++) {
+                struct per_cpu_pageset *pset;
+                struct per_cpu_pages *pcp;
+
+                pset = zone_pcp(zone, cpu);
+                pcp = &pset->pcp;
+
+                local_irq_save(flags);
+                free_pages_bulk(zone, pcp->count, &pcp->list, 0);
+                setup_pageset(pset, batch);
+                local_irq_restore(flags);
+        }
+        return 0;
+}
+
+void zone_pcp_update(struct zone *zone)
+{
+        stop_machine(__zone_pcp_update, zone, NULL);
+}
+
 static __meminit void zone_pcp_init(struct zone *zone)
 {
         int cpu;