[PATCH] x86_64: Don't reserve hotplug CPUs by default

Most users don't need it so no need to waste memory.
This means an user has to specify the appropiate number of
hotplug CPUs on the command line with additional_cpus=...
or fix their BIOS to follow the convention in
Documentation/x86-64/cpu-hotplug-spec

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/Documentation/x86_64/boot-options.txt b/Documentation/x86_64/boot-options.txt
index e566aff..72ab9b9 100644
--- a/Documentation/x86_64/boot-options.txt
+++ b/Documentation/x86_64/boot-options.txt
@@ -125,7 +125,7 @@
   cpumask=MASK   only use cpus with bits set in mask
 
   additional_cpus=NUM Allow NUM more CPUs for hotplug
-		 (defaults are specified by the BIOS or half the available CPUs)
+		 (defaults are specified by the BIOS, see Documentation/x86_64/cpu-hotplug-spec)
 
 NUMA