x86/intel_rdt: Add documentation for "info/last_cmd_status"

New file in the "info" directory helps diagnose what went wrong
when using the /sys/fs/resctrl file system

Signed-off-by: Tony Luck <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: Fenghua Yu <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Vikas Shivappa <[email protected]>
Cc: Boris Petkov <[email protected]>
Cc: Reinette Chatre <[email protected]>
Link: https://lkml.kernel.org/r/387e78e444582403c2454479e576caf5721a363f.1506382469.git.tony.luck@intel.com
This commit is contained in:
Tony Luck 2017-09-25 16:39:38 -07:00 • committed by Thomas Gleixner
commit 165d3ad884

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@ -87,6 +87,17 @@ with the following files:
bytes) at which a previously used LLC_occupancy
counter can be considered for re-use.
Finally, in the top level of the "info" directory there is a file
named "last_cmd_status". This is reset with every "command" issued
via the file system (making new directories or writing to any of the
control files). If the command was successful, it will read as "ok".
If the command failed, it will provide more information that can be
conveyed in the error returns from file operations. E.g.
# echo L3:0=f7 > schemata
bash: echo: write error: Invalid argument
# cat info/last_cmd_status
mask f7 has non-consecutive 1-bits
Resource alloc and monitor groups
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