path: root/tools/power/x86/turbostat/turbostat.8

.TH TURBOSTAT 8
.SH NAME
turbostat \- Report processor frequency and idle statistics
.SH SYNOPSIS
.ft B
.B turbostat
.RB [ Options ]
.RB command
.br
.B turbostat
.RB [ Options ]
.RB [ "\--interval seconds" ]
.SH DESCRIPTION
\fBturbostat \fP reports processor topology, frequency,
idle power-state statistics, temperature and power on X86 processors.
There are two ways to invoke turbostat.
The first method is to supply a
\fBcommand\fP, which is forked and statistics are printed
upon its completion.
The second method is to omit the command,
and turbostat displays statistics every 5 seconds.
The 5-second interval can be changed using the --interval option.
.PP
Some information is not available on older processors.
.SS Options
Options can be specified with a single or double '-', and only as much of the option
name as necessary to disambiguate it from others is necessary.  Note that options are case-sensitive.
\fB--Counter MSR#\fP shows the delta of the specified 64-bit MSR counter.
.PP
\fB--counter MSR#\fP shows the delta of the specified 32-bit MSR counter.
.PP
\fB--Dump\fP displays the raw counter values.
.PP
\fB--debug\fP displays additional system configuration information.  Invoking this parameter
more than once may also enable internal turbostat debug information.
.PP
\fB--interval seconds\fP overrides the default 5.0 second measurement interval.
.PP
\fB--out output_file\fP turbostat output is written to the specified output_file.
The file is truncated if it already exists, and it is created if it does not exist.
.PP
\fB--help\fP displays usage for the most common parameters.
.PP
\fB--Joules\fP displays energy in Joules, rather than dividing Joules by time to print power in Watts.
.PP
\fB--MSR MSR#\fP shows the specified 64-bit MSR value.
.PP
\fB--msr MSR#\fP shows the specified 32-bit MSR value.
.PP
\fB--Package\fP limits output to the system summary plus the 1st thread in each Package.
.PP
\fB--processor\fP limits output to the system summary plus the 1st thread in each processor of each package.  Ie. it skips hyper-threaded siblings.
.PP
\fB--Summary\fP limits output to a 1-line System Summary for each interval.
.PP
\fB--TCC temperature\fP sets the Thermal Control Circuit temperature for systems which do not export that value.  This is used for making sense of the Digital Thermal Sensor outputs, as they return degrees Celsius below the TCC activation temperature.
.PP
\fB--version\fP displays the version.
.PP
The \fBcommand\fP parameter forks \fBcommand\fP, and upon its exit,
displays the statistics gathered since it was forked.
.PP
.SH DEFAULT FIELD DESCRIPTIONS
.nf
\fBCPU\fP Linux CPU (logical processor) number.  Yes, it is okay that on many systems the CPUs are not listed in numerical order -- for efficiency reasons, turbostat runs in topology order, so HT siblings appear together.
\fBAVG_MHz\fP number of cycles executed divided by time elapsed.
\fBBusy%\fP percent of the interval that the CPU retired instructions, aka. % of time in "C0" state.
\fBBzy_MHz\fP average clock rate while the CPU was busy (in "c0" state).
\fBTSC_MHz\fP average MHz that the TSC ran during the entire interval.
.fi
.PP
.SH DEBUG FIELD DESCRIPTIONS
.nf
\fBPackage\fP processor package number.
\fBCore\fP processor core number.
Note that multiple CPUs per core indicate support for Intel(R) Hyper-Threading Technology (HT).
\fBCPU%c1, CPU%c3, CPU%c6, CPU%c7\fP show the percentage residency in hardware core idle states.
\fBCoreTmp\fP Degrees Celsius reported by the per-core Digital Thermal Sensor.
\fBPkgTtmp\fP Degrees Celsius reported by the per-package Package Thermal Monitor.
\fBPkg%pc2, Pkg%pc3, Pkg%pc6, Pkg%pc7\fP percentage residency in hardware package idle states.
\fBPkgWatt\fP Watts consumed by the whole package.
\fBCorWatt\fP Watts consumed by the core part of the package.
\fBGFXWatt\fP Watts consumed by the Graphics part of the package -- available only on client processors.
\fBRAMWatt\fP Watts consumed by the DRAM DIMMS -- available only on server processors.
\fBPKG_%\fP percent of the interval that RAPL throttling was active on the Package.
\fBRAM_%\fP percent of the interval that RAPL throttling was active on DRAM.
.fi
.PP
.SH PERIODIC EXAMPLE
Without any parameters, turbostat displays statistics ever 5 seconds.
Periodic output goes to stdout, by default, unless --out is used to specify an output file.
The 5-second interval can be changed with th "-i sec" option.
Or a command may be specified as in "FORK EXAMPLE" below.
.nf
[root@hsw]# ./turbostat
     CPU Avg_MHz   Busy% Bzy_MHz TSC_MHz
       -     488   12.51    3898    3498
       0       0    0.01    3885    3498
       4    3897   99.99    3898    3498
       1       0    0.00    3861    3498
       5       0    0.00    3882    3498
       2       1    0.02    3894    3498
       6       2    0.06    3898    3498
       3       0    0.00    3849    3498
       7       0    0.00    3877    3498

.fi
.SH DEBUG EXAMPLE
The "--debug" option prints additional system information before measurements:

The first row of statistics is a summary for the entire system.
For residency % columns, the summary is a weighted average.
For Temperature columns, the summary is the column maximum.
For Watts columns, the summary is a system total.
Subsequent rows show per-CPU statistics.
.nf
turbostat version 4.1 10-Feb, 2015 - Len Brown <lenb@kernel.org>
CPUID(0): GenuineIntel 13 CPUID levels; family:model:stepping 0x6:3c:3 (6:60:3)
CPUID(6): APERF, DTS, PTM, EPB
RAPL: 3121 sec. Joule Counter Range, at 84 Watts
cpu0: MSR_NHM_PLATFORM_INFO: 0x80838f3012300
8 * 100 = 800 MHz max efficiency
35 * 100 = 3500 MHz TSC frequency
cpu0: MSR_IA32_POWER_CTL: 0x0004005d (C1E auto-promotion: DISabled)
cpu0: MSR_NHM_SNB_PKG_CST_CFG_CTL: 0x1e000400 (UNdemote-C3, UNdemote-C1, demote-C3, demote-C1, UNlocked: pkg-cstate-limit=0: pc0)
cpu0: MSR_TURBO_RATIO_LIMIT: 0x25262727
37 * 100 = 3700 MHz max turbo 4 active cores
38 * 100 = 3800 MHz max turbo 3 active cores
39 * 100 = 3900 MHz max turbo 2 active cores
39 * 100 = 3900 MHz max turbo 1 active cores
cpu0: MSR_IA32_ENERGY_PERF_BIAS: 0x00000006 (balanced)
cpu0: MSR_CORE_PERF_LIMIT_REASONS, 0x31200000 (Active: ) (Logged: Auto-HWP, Amps, MultiCoreTurbo, Transitions, )
cpu0: MSR_GFX_PERF_LIMIT_REASONS, 0x00000000 (Active: ) (Logged: )
cpu0: MSR_RING_PERF_LIMIT_REASONS, 0x0d000000 (Active: ) (Logged: Amps, PkgPwrL1, PkgPwrL2, )
cpu0: MSR_RAPL_POWER_UNIT: 0x000a0e03 (0.125000 Watts, 0.000061 Joules, 0.000977 sec.)
cpu0: MSR_PKG_POWER_INFO: 0x000002a0 (84 W TDP, RAPL 0 - 0 W, 0.000000 sec.)
cpu0: MSR_PKG_POWER_LIMIT: 0x428348001a82a0 (UNlocked)
cpu0: PKG Limit #1: ENabled (84.000000 Watts, 8.000000 sec, clamp DISabled)
cpu0: PKG Limit #2: ENabled (105.000000 Watts, 0.002441* sec, clamp DISabled)
cpu0: MSR_PP0_POLICY: 0
cpu0: MSR_PP0_POWER_LIMIT: 0x00000000 (UNlocked)
cpu0: Cores Limit: DISabled (0.000000 Watts, 0.000977 sec, clamp DISabled)
cpu0: MSR_PP1_POLICY: 0
cpu0: MSR_PP1_POWER_LIMIT: 0x00000000 (UNlocked)
cpu0: GFX Limit: DISabled (0.000000 Watts, 0.000977 sec, clamp DISabled)
cpu0: MSR_IA32_TEMPERATURE_TARGET: 0x00641400 (100 C)
cpu0: MSR_IA32_PACKAGE_THERM_STATUS: 0x88340800 (48 C)
cpu0: MSR_IA32_THERM_STATUS: 0x88340000 (48 C +/- 1)
cpu1: MSR_IA32_THERM_STATUS: 0x88440000 (32 C +/- 1)
cpu2: MSR_IA32_THERM_STATUS: 0x88450000 (31 C +/- 1)
cpu3: MSR_IA32_THERM_STATUS: 0x88490000 (27 C +/- 1)
    Core     CPU Avg_MHz   Busy% Bzy_MHz TSC_MHz     SMI  CPU%c1  CPU%c3  CPU%c6  CPU%c7 CoreTmp  PkgTmp PkgWatt CorWatt GFXWatt
       -       -     493   12.64    3898    3498       0   12.64    0.00    0.00   74.72      47      47   21.62   13.74    0.00
       0       0       4    0.11    3894    3498       0   99.89    0.00    0.00    0.00      47      47   21.62   13.74    0.00
       0       4    3897   99.98    3898    3498       0    0.02
       1       1       7    0.17    3887    3498       0    0.04    0.00    0.00   99.79      32
       1       5       0    0.00    3885    3498       0    0.21
       2       2      29    0.76    3895    3498       0    0.10    0.01    0.01   99.13      32
       2       6       2    0.06    3896    3498       0    0.80
       3       3       1    0.02    3832    3498       0    0.03    0.00    0.00   99.95      28
       3       7       0    0.00    3879    3498       0    0.04
^C

.fi
The \fBmax efficiency\fP frequency, a.k.a. Low Frequency Mode, is the frequency
available at the minimum package voltage.  The \fBTSC frequency\fP is the base
frequency of the processor -- this should match the brand string
in /proc/cpuinfo.  This base frequency
should be sustainable on all CPUs indefinitely, given nominal power and cooling.
The remaining rows show what maximum turbo frequency is possible
depending on the number of idle cores.  Note that not all information is
available on all processors.
.PP
The --debug option adds additional columns to the measurement ouput, including CPU idle power-state residency processor temperature sensor readinds.
See the field definitions above.
.SH FORK EXAMPLE
If turbostat is invoked with a command, it will fork that command
and output the statistics gathered after the command exits.
In this case, turbostat output goes to stderr, by default.
Output can instead be saved to a file using the --out option.
eg. Here a cycle soaker is run on 1 CPU (see %c0) for a few seconds
until ^C while the other CPUs are mostly idle:

.nf
root@hsw: turbostat cat /dev/zero > /dev/null
^C
     CPU Avg_MHz   Busy% Bzy_MHz TSC_MHz
       -     482   12.51    3854    3498
       0       0    0.01    1960    3498
       4       0    0.00    2128    3498
       1       0    0.00    3003    3498
       5    3854   99.98    3855    3498
       2       0    0.01    3504    3498
       6       3    0.08    3884    3498
       3       0    0.00    2553    3498
       7       0    0.00    2126    3498
10.783983 sec

.fi
Above the cycle soaker drives cpu5 up its 3.9 GHz turbo limit.
The first row shows the average MHz and Busy% across all the processors in the system.

Note that the Avg_MHz column reflects the total number of cycles executed
divided by the measurement interval.  If the Busy% column is 100%,
then the processor was running at that speed the entire interval.
The Avg_MHz multiplied by the Busy% results in the Bzy_MHz --
which is the average frequency while the processor was executing --
not including any non-busy idle time.

.SH NOTES

.B "turbostat "
must be run as root.
Alternatively, non-root users can be enabled to run turbostat this way:

# setcap cap_sys_rawio=ep ./turbostat

# chmod +r /dev/cpu/*/msr

.B "turbostat "
reads hardware counters, but doesn't write them.
So it will not interfere with the OS or other programs, including
multiple invocations of itself.

\fBturbostat \fP
may work poorly on Linux-2.6.20 through 2.6.29,
as \fBacpi-cpufreq \fPperiodically cleared the APERF and MPERF MSRs
in those kernels.

AVG_MHz = APERF_delta/measurement_interval.  This is the actual
number of elapsed cycles divided by the entire sample interval --
including idle time.  Note that this calculation is resilient
to systems lacking a non-stop TSC.

TSC_MHz = TSC_delta/measurement_interval.
On a system with an invariant TSC, this value will be constant
and will closely match the base frequency value shown
in the brand string in /proc/cpuinfo.  On a system where
the TSC stops in idle, TSC_MHz will drop
below the processor's base frequency.

Busy% = MPERF_delta/TSC_delta

Bzy_MHz = TSC_delta/APERF_delta/MPERF_delta/measurement_interval

Note that these calculations depend on TSC_delta, so they
are not reliable during intervals when TSC_MHz is not running at the base frequency.

Turbostat data collection is not atomic.
Extremely short measurement intervals (much less than 1 second),
or system activity that prevents turbostat from being able
to run on all CPUS to quickly collect data, will result in
inconsistent results.

The APERF, MPERF MSRs are defined to count non-halted cycles.
Although it is not guaranteed by the architecture, turbostat assumes
that they count at TSC rate, which is true on all processors tested to date.

.SH REFERENCES
Volume 3B: System Programming Guide"
http://www.intel.com/products/processor/manuals/

.SH FILES
.ta
.nf
/dev/cpu/*/msr
.fi

.SH "SEE ALSO"
msr(4), vmstat(8)
.PP
.SH AUTHOR
.nf
Written by Len Brown <len.brown@intel.com>