Commit 7553e8f2 authored Jun 22, 2011 by David Rientjes Committed by Linus Torvalds Jun 22, 2011

mm, hotplug: fix error handling in mem_online_node()



The error handling in mem_online_node() is incorrect: hotadd_new_pgdat()
returns NULL if the new pgdat could not have been allocated and a pointer
to it otherwise.

mem_online_node() should fail if hotadd_new_pgdat() fails, not the
inverse.  This fixes an issue when memoryless nodes are not onlined and
their sysfs interface is not registered when their first cpu is brought
up.

The bug was introduced by commit cf23422b ("cpu/mem hotplug: enable
CPUs online before local memory online") iow v2.6.35.

Signed-off-by: David Rientjes <rientjes@google.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent b1d7dd80

mm/memory_hotplug.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -521,7 +521,7 @@ int mem_online_node(int nid)

		lock_memory_hotplug();
		pgdat = hotadd_new_pgdat(nid, 0);
		if (pgdat) {
		if (!pgdat) {
		ret = -ENOMEM;
		goto out;
		}

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