cpu-hotplug: refcount based cpu hotplug
This patch implements a Refcount + Waitqueue based model for
cpu-hotplug.
Now, a thread which wants to prevent cpu-hotplug, will bump up a global
refcount and the thread which wants to perform a cpu-hotplug operation
will block till the global refcount goes to zero.
The readers, if any, during an ongoing cpu-hotplug operation are blocked
until the cpu-hotplug operation is over.
Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Paul Jackson <pj@sgi.com> [For !CONFIG_HOTPLUG_CPU ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/init/main.c b/init/main.c
index 80b04b6..f287ca5 100644
--- a/init/main.c
+++ b/init/main.c
@@ -607,6 +607,7 @@
vfs_caches_init_early();
cpuset_init_early();
mem_init();
+ cpu_hotplug_init();
kmem_cache_init();
setup_per_cpu_pageset();
numa_policy_init();