[PATCH v9 9/9] x86/resctrl: Document the new "mba_MBps_event" file

[Tony Luck <tony.luck@intel.com>]

Add a section to document a new read/write file that shows/sets the memory
bandwidth event used to control bandwidth used by each ctrl_mon group.

Signed-off-by: Tony Luck <tony.luck@intel.com>
---
 Documentation/arch/x86/resctrl.rst | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst
index a824affd741d..6768fc1fad16 100644
--- a/Documentation/arch/x86/resctrl.rst
+++ b/Documentation/arch/x86/resctrl.rst
@@ -384,6 +384,16 @@ When monitoring is enabled all MON groups will also contain:
 	Available only with debug option. The identifier used by hardware
 	for the monitor group. On x86 this is the RMID.
 
+When the "mba_MBps" mount option is used all CTRL_MON groups will also contain:
+
+"mba_MBps_event":
+	Reading this file shows which memory bandwidth event is used
+	as input to the software feedback loop that keeps memory bandwidth
+	below the value specified in the schemata file. Writing the
+	name of one of the supported memory bandwidth events found in
+	/sys/fs/resctrl/info/L3_MON/mon_features changes the input
+	event.
+
 Resource allocation rules
 -------------------------
 
-- 
2.47.0