[S390] cpu topology: introduce kernel parameter

Introduce a topology=[on|off] kernel parameter which allows to switch
cpu topology on/off. Default will be off, since it looks like that for
some workloards this doesn't behave very well (on s390).

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index c9115c1b672c..09ede6c90ad7 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2252,6 +2252,14 @@ and is between 256 and 4096 characters. It is defined in the file
                         See comment before function dc390_setup() in
                         drivers/scsi/tmscsim.c.
 
+        topology=       [S390]
+                        Format: {off | on}
+                        Specify if the kernel should make use of the cpu
+                        topology informations if the hardware supports these.
+                        The scheduler will make use of these informations and
+                        e.g. base its process migration decisions on it.
+                        Default is off.
+
         tp720=          [HW,PS2]
 
         trix=           [HW,OSS] MediaTrix AudioTrix Pro