mm/memory_hotplug.c: move register_memory_resource out of the lock_memory_hotplug
We don't need to do register_memory_resource() under
lock_memory_hotplug() since it has its own lock and doesn't make any
callbacks.
Also register_memory_resource return NULL on failure so we don't have
anything to cleanup at this point.
The reason for this rfc is I was doing some experiments with hotplugging
of memory on some of our larger systems. While it seems to work, it can
be quite slow. With some preliminary digging I found that
lock_memory_hotplug is clearly ripe for breakup.
It could be broken up per nid or something but it also covers the
online_page_callback. The online_page_callback shouldn't be very hard
to break out.
Also there is the issue of various structures(wmarks come to mind) that
are only updated under the lock_memory_hotplug that would need to be
dealt with.
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Hedi <hedi@sgi.com>
Cc: Mike Travis <travis@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index a512a47..a650db2 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1107,17 +1107,18 @@
if (ret)
return ret;
- lock_memory_hotplug();
-
res = register_memory_resource(start, size);
ret = -EEXIST;
if (!res)
- goto out;
+ return ret;
{ /* Stupid hack to suppress address-never-null warning */
void *p = NODE_DATA(nid);
new_pgdat = !p;
}
+
+ lock_memory_hotplug();
+
new_node = !node_online(nid);
if (new_node) {
pgdat = hotadd_new_pgdat(nid, start);