xen: document balloon driver sysfs files

Add ABI documentation for the balloon driver's sysfs files.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Daniel Kiper <dkiper@net-space.pl>
[v2: Added comments from Daniel]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

1 files changed, 77 insertions, 0 deletions

diff --git a/Documentation/ABI/stable/sysfs-devices-system-xen_memory b/Documentation/ABI/stable/sysfs-devices-system-xen_memory
new file mode 100644
index 000000000000..caa311d59ac1
--- /dev/null
+++ b/Documentation/ABI/stable/sysfs-devices-system-xen_memory
@@ -0,0 +1,77 @@
+What:           /sys/devices/system/xen_memory/xen_memory0/max_retry_count
+Date:           May 2011
+KernelVersion:  2.6.39
+Contact:        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+                The maximum number of times the balloon driver will
+                attempt to increase the balloon before giving up.  See
+                also 'retry_count' below.
+                A value of zero means retry forever and is the default one.
+
+What:           /sys/devices/system/xen_memory/xen_memory0/max_schedule_delay
+Date:           May 2011
+KernelVersion:  2.6.39
+Contact:        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+                The limit that 'schedule_delay' (see below) will be
+                increased to. The default value is 32 seconds.
+
+What:           /sys/devices/system/xen_memory/xen_memory0/retry_count
+Date:           May 2011
+KernelVersion:  2.6.39
+Contact:        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+                The current number of times that the balloon driver
+                has attempted to increase the size of the balloon.
+                The default value is one. With max_retry_count being
+                zero (unlimited), this means that the driver will attempt
+                to retry with a 'schedule_delay' delay.
+
+What:           /sys/devices/system/xen_memory/xen_memory0/schedule_delay
+Date:           May 2011
+KernelVersion:  2.6.39
+Contact:        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+                The time (in seconds) to wait between attempts to
+                increase the balloon.  Each time the balloon cannot be
+                increased, 'schedule_delay' is increased (until
+                'max_schedule_delay' is reached at which point it
+                will use the max value).
+
+What:           /sys/devices/system/xen_memory/xen_memory0/target
+Date:           April 2008
+KernelVersion:  2.6.26
+Contact:        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+                The target number of pages to adjust this domain's
+                memory reservation to.
+
+What:           /sys/devices/system/xen_memory/xen_memory0/target_kb
+Date:           April 2008
+KernelVersion:  2.6.26
+Contact:        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+                As target above, except the value is in KiB.
+
+What:           /sys/devices/system/xen_memory/xen_memory0/info/current_kb
+Date:           April 2008
+KernelVersion:  2.6.26
+Contact:        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+                Current size (in KiB) of this domain's memory
+                reservation.
+
+What:           /sys/devices/system/xen_memory/xen_memory0/info/high_kb
+Date:           April 2008
+KernelVersion:  2.6.26
+Contact:        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+                Amount (in KiB) of high memory in the balloon.
+
+What:           /sys/devices/system/xen_memory/xen_memory0/info/low_kb
+Date:           April 2008
+KernelVersion:  2.6.26
+Contact:        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+                Amount (in KiB) of low (or normal) memory in the
+                balloon.