[PATCH] s390: possible_cpus parameter

Introduce possible_cpus command line option.  Hard sets the number of bits set
in cpu_possible_map.  Unlike the additional_cpus parameter this one guarantees
that num_possible_cpus() will stay constant even if the system gets rebooted
and a different number of cpus are present at startup.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/Documentation/cpu-hotplug.txt b/Documentation/cpu-hotplug.txt
index 4d3355da0e26..e71bc6cbbc5e 100644
--- a/Documentation/cpu-hotplug.txt
+++ b/Documentation/cpu-hotplug.txt
@@ -58,6 +58,12 @@ mark such hot-pluggable cpus as disabled entries, one could use this
 parameter "additional_cpus=x" to represent those cpus in the cpu_possible_map.
 
 
+possible_cpus=n         [s390 only] use this to set hotpluggable cpus.
+                        This option sets possible_cpus bits in
+                        cpu_possible_map. Thus keeping the numbers of bits set
+                        constant even if the machine gets rebooted.
+                        This option overrides additional_cpus.
+
 CPU maps and such
 -----------------
 [More on cpumaps and primitive to manipulate, please check