Writing an invalid schemata with no domain values (e.g., "(L3|MB):"),
results in a silent failure, i.e. the last_cmd_status returns OK,
Check for an empty value and set the result string with a proper error
message and return -EINVAL.
Before the fix:
# mkdir /sys/fs/resctrl/p1
# echo "L3:" > /sys/fs/resctrl/p1/schemata
(silent failure)
# cat /sys/fs/resctrl/info/last_cmd_status
ok
# echo "MB:" > /sys/fs/resctrl/p1/schemata
(silent failure)
# cat /sys/fs/resctrl/info/last_cmd_status
ok
After the fix:
# mkdir /sys/fs/resctrl/p1
# echo "L3:" > /sys/fs/resctrl/p1/schemata
-bash: echo: write error: Invalid argument
# cat /sys/fs/resctrl/info/last_cmd_status
Missing 'L3' value
# echo "MB:" > /sys/fs/resctrl/p1/schemata
-bash: echo: write error: Invalid argument
# cat /sys/fs/resctrl/info/last_cmd_status
Missing 'MB' value
[ Tony: This is an unintended side effect of the patch earlier to allow the
user to just write the value they want to change. While allowing
user to specify less than all of the values, it also allows an
empty value. ]
Fixes: c4026b7b95 ("x86/intel_rdt: Implement "update" mode when writing schemata file")
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lkml.kernel.org/r/20171110191624.20280-1-tony.luck@intel.com
About the only tricky case is trying to move a task into a monitor
group that is a subdirectory of a different control group. But cover
the simple cases too.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vikas Shivappa <vikas.shivappa@intel.com>
Cc: Boris Petkov <bp@suse.de>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lkml.kernel.org/r/f1841cce6a242aed37cb926dee8942727331bf78.1506382469.git.tony.luck@intel.com
Save helpful descriptions of what went wrong when writing a
schemata file.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vikas Shivappa <vikas.shivappa@intel.com>
Cc: Boris Petkov <bp@suse.de>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lkml.kernel.org/r/9d6cef757dc88639c8ab47f1e7bc1b081a84bb88.1506382469.git.tony.luck@intel.com
Add a mon_data directory for the root rdtgroup and all other rdtgroups.
The directory holds all of the monitored data for all domains and events
of all resources being monitored.
The mon_data itself has a list of directories in the format
mon_<domain_name>_<domain_id>. Each of these subdirectories contain one
file per event in the mode "0444". Reading the file displays a snapshot
of the monitored data for the event the file represents.
For ex, on a 2 socket Broadwell with llc_occupancy being
monitored the mon_data contents look as below:
$ ls /sys/fs/resctrl/p1/mon_data/
mon_L3_00
mon_L3_01
Each domain directory has one file per event:
$ ls /sys/fs/resctrl/p1/mon_data/mon_L3_00/
llc_occupancy
To read current llc_occupancy of ctrl_mon group p1
$ cat /sys/fs/resctrl/p1/mon_data/mon_L3_00/llc_occupancy
33789096
[This patch idea is based on Tony's sample patches to organise data in a
per domain directory and have one file per event (and use the fp->priv to
store mon data bits)]
Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: ravi.v.shankar@intel.com
Cc: tony.luck@intel.com
Cc: fenghua.yu@intel.com
Cc: peterz@infradead.org
Cc: eranian@google.com
Cc: vikas.shivappa@intel.com
Cc: ak@linux.intel.com
Cc: davidcc@google.com
Cc: reinette.chatre@intel.com
Link: http://lkml.kernel.org/r/1501017287-28083-20-git-send-email-vikas.shivappa@linux.intel.com
Xiaochen Shen