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authorPrarit Bhargava <prarit@redhat.com>2014-04-24 18:32:07 +0400
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-05-07 02:19:06 +0400
commite091abc7f92b45010992df1ceb5da023d8faf13b (patch)
tree526d39f91334dbbf2c1d9600a546bd3cbae127f2 /tools/power/cpupower/man
parent3482124a6a22c631df23958df497f000ba0e1667 (diff)
downloadlinux-e091abc7f92b45010992df1ceb5da023d8faf13b.tar.xz
PM / tools: cpupower: add option to display values without round offs
The command "cpupower frequency-info" can be used when using cpupower to monitor and test processor behaviour to determine if the processor is behaving as expected. This data can be compared to the output of /proc/cpuinfo or the output of /sys/devices/system/cpu/cpuX/cpufreq/scaling_available_frequencies to determine if the cpu is in an expected state. When doing this I noticed comparison test failures due to the way the data is displayed in cpupower. For example, [root@intel-s3e37-02 cpupower]# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies 2262000 2261000 2128000 1995000 1862000 1729000 1596000 1463000 1330000 1197000 1064000 compared to [root@intel-s3e37-02 cpupower]# cpupower frequency-info analyzing CPU 0: driver: acpi-cpufreq CPUs which run at the same hardware frequency: 0 CPUs which need to have their frequency coordinated by software: 0 maximum transition latency: 10.0 us. hardware limits: 1.06 GHz - 2.26 GHz available frequency steps: 2.26 GHz, 2.26 GHz, 2.13 GHz, 2.00 GHz, 1.86 GHz, 1.73 GHz, 1.60 GHz, 1.46 GHz, 1.33 GHz, 1.20 GHz, 1.06 GHz available cpufreq governors: conservative, userspace, powersave, ondemand, performance current policy: frequency should be within 1.06 GHz and 2.26 GHz. The governor "performance" may decide which speed to use within this range. current CPU frequency is 2.26 GHz (asserted by call to hardware). boost state support: Supported: yes Active: yes shows very different values for the available frequency steps. The cpupower output rounds off values at 2 decimal points and this causes problems with test scripts. For example, with the data above, 1.064 is 1.06 1.197 is 1.20 1.596 is 1.60 1.995 is 2.00 2.128 is 2.13 and most confusingly, 2.261 is 2.26 2.262 is 2.26 Truncating these values serves no real purpose other than making the output pretty. Since the default has been to round off these values I am adding a -n/--no-rounding option to the cpupower utility that will display the data without rounding off the still significant digits. After patch, analyzing CPU 0: driver: acpi-cpufreq CPUs which run at the same hardware frequency: 0 CPUs which need to have their frequency coordinated by software: 0 maximum transition latency: 10.000 us. hardware limits: 1.064000 GHz - 2.262000 GHz available frequency steps: 2.262000 GHz, 2.261000 GHz, 2.128000 GHz, 1.995000 GHz, 1.862000 GHz, 1.729000 GHz, 1.596000 GHz, 1.463000 GHz, 1.330000 GHz, 1.197000 GHz, 1.064000 GHz available cpufreq governors: conservative, userspace, powersave, ondemand, performance current policy: frequency should be within 1.064000 GHz and 2.262000 GHz. The governor "performance" may decide which speed to use within this range. current CPU frequency is 2.262000 GHz (asserted by call to hardware). boost state support: Supported: yes Active: yes Acked-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Prarit Bhargava <prarit@redhat.com> [rjw: Subject] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'tools/power/cpupower/man')
-rw-r--r--tools/power/cpupower/man/cpupower-frequency-info.13
1 files changed, 3 insertions, 0 deletions
diff --git a/tools/power/cpupower/man/cpupower-frequency-info.1 b/tools/power/cpupower/man/cpupower-frequency-info.1
index 4a1918ea8f9c..9c85a382e355 100644
--- a/tools/power/cpupower/man/cpupower-frequency-info.1
+++ b/tools/power/cpupower/man/cpupower-frequency-info.1
@@ -50,6 +50,9 @@ Prints out information like provided by the /proc/cpufreq interface in 2.4. and
\fB\-m\fR \fB\-\-human\fR
human\-readable output for the \-f, \-w, \-s and \-y parameters.
.TP
+\fB\-n\fR \fB\-\-no-rounding\fR
+Output frequencies and latencies without rounding off values.
+.TP
.SH "REMARKS"
.LP
By default only values of core zero are displayed. How to display settings of