mem-hotplug: fix potential race while building zonelist for new populated zone

[pandora-kernel.git] / kernel / cpu.c

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 3e8b3ba..124ad9d 100644 (file)
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -357,8 +357,11 @@ int __cpuinit cpu_up(unsigned int cpu)
                return -ENOMEM;
        }
 
-       if (pgdat->node_zonelists->_zonerefs->zone == NULL)
+       if (pgdat->node_zonelists->_zonerefs->zone == NULL) {
+               mutex_lock(&zonelists_mutex);
                build_all_zonelists(NULL);
+               mutex_unlock(&zonelists_mutex);
+       }
 #endif
 
        cpu_maps_update_begin();