Documentation: ABI: /sys/devices/system/cpu/ topology files

Add brief descriptions for the following sysfs files:

	/sys/devices/system/cpu/kernel_max
	/sys/devices/system/cpu/offline
	/sys/devices/system/cpu/online
	/sys/devices/system/cpu/possible
	/sys/devices/system/cpu/present

Excerpted the relevant information from Documentation/cputopology.txt
and pointed back to cputopology.txt as the authoritative source of
information.

Cc: Mike Travis <travis@sgi.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 28 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu
index 86126b187ae6..871acdbeed1a 100644
--- a/Documentation/ABI/testing/sysfs-devices-system-cpu
+++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
@@ -10,6 +10,34 @@ Description:
                 /sys/devices/system/cpu/cpu#/
 
 
+What:           /sys/devices/system/cpu/kernel_max
+                /sys/devices/system/cpu/offline
+                /sys/devices/system/cpu/online
+                /sys/devices/system/cpu/possible
+                /sys/devices/system/cpu/present
+Date:           December 2008
+Contact:        Linux kernel mailing list <linux-kernel@vger.kernel.org>
+Description:    CPU topology files that describe kernel limits related to
+                hotplug. Briefly:
+
+                kernel_max: the maximum cpu index allowed by the kernel
+                configuration.
+
+                offline: cpus that are not online because they have been
+                HOTPLUGGED off or exceed the limit of cpus allowed by the
+                kernel configuration (kernel_max above).
+
+                online: cpus that are online and being scheduled.
+
+                possible: cpus that have been allocated resources and can be
+                brought online if they are present.
+
+                present: cpus that have been identified as being present in
+                the system.
+
+                See Documentation/cputopology.txt for more information.
+
+
 What:      /sys/devices/system/cpu/cpu*/cache/index*/cache_disable_X
 Date:      August 2008
 KernelVersion:  2.6.27