linux/tools
Prarit Bhargava e091abc7f9 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>
2014-05-07 00:19:06 +02:00
..
cgroup cgroups: fix cgroup_event_listener error handling 2013-01-08 10:00:44 -08:00
firewire tools/firewire: nosy-dump: check for allocation failure 2012-12-02 20:10:18 +01:00
hv Tools: hv: Handle the case when the target file exists correctly 2014-04-16 14:10:36 -07:00
include perf tools: Move hash.h header 2014-02-18 09:34:49 -03:00
lguest tools/lguest: offer VIRTIO_F_ANY_LAYOUT for net device. 2013-07-15 11:18:32 +09:30
lib perf tools: Remove extra '/' character in events file path 2014-04-30 17:02:24 +02:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-03-14 22:31:55 -04:00
nfsd
perf perf tests x86: Fix stack map lookup in dwarf unwind test 2014-04-30 17:02:31 +02:00
power PM / tools: cpupower: add option to display values without round offs 2014-05-07 00:19:06 +02:00
scripts tools lib traceevent: Add global QUIET_CC_FPIC build output 2013-12-19 16:18:10 -03:00
testing This just contains a single update by Satoru Takeuchi, which adds 2014-04-04 21:27:43 -07:00
thermal/tmon tools/thermal: Introduce tmon, a tool for thermal subsystem 2013-11-07 08:45:34 +08:00
usb usb: tools: fix a regression issue that gcc can't link to pthread 2013-12-04 15:10:54 -08:00
virtio tools/virtio: add a missing ) 2014-03-13 11:23:25 +10:30
vm tools/vm/page-types.c: page-cache sniffing feature 2014-04-07 16:35:52 -07:00
Makefile Adding makefile for tools/hv 2014-02-15 11:52:35 -08:00