12 Commits

Author SHA1 Message Date
Len Brown
15aaa34654 tools turbostat: harden against cpu online/offline
Sometimes users have turbostat running in interval mode
when they take processors offline/online.

Previously, turbostat would survive, but not gracefully.

Tighten up the error checking so turbostat notices
changesn sooner, and print just 1 line on change:

turbostat: re-initialized with num_cpus %d

Signed-off-by: Len Brown <len.brown@intel.com>
2012-03-29 22:27:19 -04:00
Len Brown
88c3281f7b tools turbostat: reduce measurement overhead due to IPIs
turbostat uses /dev/cpu/*/msr interface to read MSRs.
For modern systems, it reads 10 MSR/CPU.  This can
be observed as 10 "Function Call Interrupts"
per CPU per sample added to /proc/interrupts.

This overhead is measurable on large idle systems,
and as Yoquan Song pointed out, it can even trick
cpuidle into thinking the system is busy.

Here turbostat re-schedules itself in-turn to each
CPU so that its MSR reads will always be local.
This replaces the 10 "Function Call Interrupts"
with a single "Rescheduling interrupt" per sample
per CPU.

On an idle 32-CPU system, this shifts some residency from
the shallow c1 state to the deeper c7 state:

 # ./turbostat.old -s
   %c0  GHz  TSC    %c1    %c3    %c6    %c7   %pc2   %pc3   %pc6   %pc7
  0.27 1.29 2.29   0.95   0.02   0.00  98.77  20.23   0.00  77.41   0.00
  0.25 1.24 2.29   0.98   0.02   0.00  98.75  20.34   0.03  77.74   0.00
  0.27 1.22 2.29   0.54   0.00   0.00  99.18  20.64   0.00  77.70   0.00
  0.26 1.22 2.29   1.22   0.00   0.00  98.52  20.22   0.00  77.74   0.00
  0.26 1.38 2.29   0.78   0.02   0.00  98.95  20.51   0.05  77.56   0.00
^C
 i# ./turbostat.new -s
   %c0  GHz  TSC    %c1    %c3    %c6    %c7   %pc2   %pc3   %pc6   %pc7
  0.27 1.20 2.29   0.24   0.01   0.00  99.49  20.58   0.00  78.20   0.00
  0.27 1.22 2.29   0.25   0.00   0.00  99.48  20.79   0.00  77.85   0.00
  0.27 1.20 2.29   0.25   0.02   0.00  99.46  20.71   0.03  77.89   0.00
  0.28 1.26 2.29   0.25   0.01   0.00  99.46  20.89   0.02  77.67   0.00
  0.27 1.20 2.29   0.24   0.01   0.00  99.48  20.65   0.00  78.04   0.00

cc: Youquan Song <youquan.song@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2012-03-29 22:04:58 -04:00
Len Brown
e23da0370f tools turbostat: add summary option
turbostat -s
cuts down on the amount of output, per user request.

also treak some output whitespace and the man page.

Signed-off-by: Len Brown <len.brown@intel.com>
2012-03-29 13:22:06 -04:00
Len Brown
79ba0db69c Merge branches 'einj', 'intel_idle', 'misc', 'srat' and 'turbostat-ivb' into release 2012-01-18 01:15:54 -05:00
Len Brown
553575f1ae tools turbostat: recognize and run properly on IVB
Signed-off-by: Len Brown <len.brown@intel.com>
2011-11-18 03:32:01 -05:00
Len Brown
efb90582c5 Merge branches 'acpi', 'idle', 'mrst-pmu' and 'pm-tools' into next 2011-11-06 22:14:50 -05:00
Len Brown
d30c4b7a87 tools/power turbostat: fit output into 80 columns on snb-ep
Reduce columns for package number to 1.
If you can afford more than 9 packages,
you can also afford a terminal with more than 80 columns:-)

Also shave a column also off the package C-states

Signed-off-by: Len Brown <len.brown@intel.com>
2011-08-02 18:33:31 -04:00
Len Brown
aeae1e92da tools/power turbostat: less verbose debugging
dump only the counters which are active

Signed-off-by: Len Brown <len.brown@intel.com>
2011-07-03 21:41:33 -04:00
Justin P. Mattock
6eab04a876 treewide: remove extra semicolons
Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-04-10 17:01:05 +02:00
Len Brown
a829eb4d7e tools: turbostat: style updates
Follow kernel coding style traditions more closely.
Delete typedef, re-name "per cpu counters" to
simply be counters etc.

This patch changes no functionality.

Suggested-by: Thiago Farina <tfransosi@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2011-02-10 23:58:13 -05:00
Thomas Renninger
8209e054b6 tools: turbostat: fix bitwise and operand
bug could cause false positive on indicating
presence of invarient TSC or APERF support.

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
2011-02-10 23:58:11 -05:00
Len Brown
103a8fea9b tools: create power/x86/turbostat
turbostat is a Linux tool to observe proper operation
of Intel(R) Turbo Boost Technology.

turbostat displays the actual processor frequency
on x86 processors that include APERF and MPERF MSRs.

Note that turbostat is of limited utility on Linux
kernels 2.6.29 and older, as acpi_cpufreq cleared
APERF/MPERF up through that release.

On Intel Core i3/i5/i7 (Nehalem) and newer processors,
turbostat also displays residency in idle power saving states,
which are necessary for diagnosing any cpuidle issues
that may have an effect on turbo-mode.

See the turbostat.8 man page for example usage.

Signed-off-by: Len Brown <len.brown@intel.com>
2011-01-11 22:46:02 -05:00