199 строки
6.5 KiB
Groff
199 строки
6.5 KiB
Groff
.TH CPUPOWER\-MONITOR "1" "22/02/2011" "" "cpupower Manual"
|
||
.SH NAME
|
||
cpupower\-monitor \- Report processor frequency and idle statistics
|
||
.SH SYNOPSIS
|
||
.ft B
|
||
.B cpupower monitor
|
||
.RB "\-l"
|
||
|
||
.B cpupower monitor
|
||
.RB [ -c ] [ "\-m <mon1>," [ "<mon2>,..." ] ]
|
||
.RB [ "\-i seconds" ]
|
||
.br
|
||
.B cpupower monitor
|
||
.RB [ -c ][ "\-m <mon1>," [ "<mon2>,..." ] ]
|
||
.RB command
|
||
.br
|
||
.SH DESCRIPTION
|
||
\fBcpupower-monitor \fP reports processor topology, frequency and idle power
|
||
state statistics. Either \fBcommand\fP is forked and
|
||
statistics are printed upon its completion, or statistics are printed periodically.
|
||
|
||
\fBcpupower-monitor \fP implements independent processor sleep state and
|
||
frequency counters. Some are retrieved from kernel statistics, some are
|
||
directly reading out hardware registers. Use \-l to get an overview which are
|
||
supported on your system.
|
||
|
||
.SH Options
|
||
.PP
|
||
\-l
|
||
.RS 4
|
||
List available monitors on your system. Additional details about each monitor
|
||
are shown:
|
||
.RS 2
|
||
.IP \(bu
|
||
The name in quotation marks which can be passed to the \-m parameter.
|
||
.IP \(bu
|
||
The number of different counters the monitor supports in brackets.
|
||
.IP \(bu
|
||
The amount of time in seconds the counters might overflow, due to
|
||
implementation constraints.
|
||
.IP \(bu
|
||
The name and a description of each counter and its processor hierarchy level
|
||
coverage in square brackets:
|
||
.RS 4
|
||
.IP \(bu
|
||
[T] \-> Thread
|
||
.IP \(bu
|
||
[C] \-> Core
|
||
.IP \(bu
|
||
[P] \-> Processor Package (Socket)
|
||
.IP \(bu
|
||
[M] \-> Machine/Platform wide counter
|
||
.RE
|
||
.RE
|
||
.RE
|
||
.PP
|
||
\-m <mon1>,<mon2>,...
|
||
.RS 4
|
||
Only display specific monitors. Use the monitor string(s) provided by \-l option.
|
||
.RE
|
||
.PP
|
||
\-i seconds
|
||
.RS 4
|
||
Measure intervall.
|
||
.RE
|
||
.PP
|
||
\-c
|
||
.RS 4
|
||
Schedule the process on every core before starting and ending measuring.
|
||
This could be needed for the Idle_Stats monitor when no other MSR based
|
||
monitor (has to be run on the core that is measured) is run in parallel.
|
||
This is to wake up the processors from deeper sleep states and let the
|
||
kernel re
|
||
-account its cpuidle (C-state) information before reading the
|
||
cpuidle timings from sysfs.
|
||
.RE
|
||
.PP
|
||
command
|
||
.RS 4
|
||
Measure idle and frequency characteristics of an arbitrary command/workload.
|
||
The executable \fBcommand\fP is forked and upon its exit, statistics gathered since it was
|
||
forked are displayed.
|
||
.RE
|
||
.PP
|
||
\-v
|
||
.RS 4
|
||
Increase verbosity if the binary was compiled with the DEBUG option set.
|
||
.RE
|
||
|
||
.SH MONITOR DESCRIPTIONS
|
||
.SS "Idle_Stats"
|
||
Shows statistics of the cpuidle kernel subsystem. Values are retrieved from
|
||
/sys/devices/system/cpu/cpu*/cpuidle/state*/.
|
||
The kernel updates these values every time an idle state is entered or
|
||
left. Therefore there can be some inaccuracy when cores are in an idle
|
||
state for some time when the measure starts or ends. In worst case it can happen
|
||
that one core stayed in an idle state for the whole measure time and the idle
|
||
state usage time as exported by the kernel did not get updated. In this case
|
||
a state residency of 0 percent is shown while it was 100.
|
||
|
||
.SS "Mperf"
|
||
The name comes from the aperf/mperf (average and maximum) MSR registers used
|
||
which are available on recent X86 processors. It shows the average frequency
|
||
(including boost frequencies).
|
||
The fact that on all recent hardware the mperf timer stops ticking in any idle
|
||
state it is also used to show C0 (processor is active) and Cx (processor is in
|
||
any sleep state) times. These counters do not have the inaccuracy restrictions
|
||
the "Idle_Stats" counters may show.
|
||
May work poorly on Linux-2.6.20 through 2.6.29, as the \fBacpi-cpufreq \fP
|
||
kernel frequency driver periodically cleared aperf/mperf registers in those
|
||
kernels.
|
||
|
||
.SS "Nehalem" "SandyBridge" "HaswellExtended"
|
||
Intel Core and Package sleep state counters.
|
||
Threads (hyperthreaded cores) may not be able to enter deeper core states if
|
||
its sibling is utilized.
|
||
Deepest package sleep states may in reality show up as machine/platform wide
|
||
sleep states and can only be entered if all cores are idle. Look up Intel
|
||
manuals (some are provided in the References section) for further details.
|
||
The monitors are named after the CPU family where the sleep state capabilities
|
||
got introduced and may not match exactly the CPU name of the platform.
|
||
For example an IvyBridge processor has sleep state capabilities which got
|
||
introduced in Nehalem and SandyBridge processor families.
|
||
Thus on an IvyBridge processor one will get Nehalem and SandyBridge sleep
|
||
state monitors.
|
||
HaswellExtended extra package sleep state capabilities are available only in a
|
||
specific Haswell (family 0x45) and probably also other future processors.
|
||
|
||
.SS "Fam_12h" "Fam_14h"
|
||
AMD laptop and desktop processor (family 12h and 14h) sleep state counters.
|
||
The registers are accessed via PCI and therefore can still be read out while
|
||
cores have been offlined.
|
||
|
||
There is one special counter: NBP1 (North Bridge P1).
|
||
This one always returns 0 or 1, depending on whether the North Bridge P1
|
||
power state got entered at least once during measure time.
|
||
Being able to enter NBP1 state also depends on graphics power management.
|
||
Therefore this counter can be used to verify whether the graphics' driver
|
||
power management is working as expected.
|
||
|
||
.SH EXAMPLES
|
||
|
||
cpupower monitor -l" may show:
|
||
.RS 4
|
||
Monitor "Mperf" (3 states) \- Might overflow after 922000000 s
|
||
|
||
...
|
||
|
||
Monitor "Idle_Stats" (3 states) \- Might overflow after 4294967295 s
|
||
|
||
...
|
||
|
||
.RE
|
||
cpupower monitor \-m "Idle_Stats,Mperf" scp /tmp/test /nfs/tmp
|
||
|
||
Monitor the scp command, show both Mperf and Idle_Stats states counter
|
||
statistics, but in exchanged order.
|
||
|
||
|
||
|
||
.RE
|
||
Be careful that the typical command to fully utilize one CPU by doing:
|
||
|
||
cpupower monitor cat /dev/zero >/dev/null
|
||
|
||
Does not work as expected, because the measured output is redirected to
|
||
/dev/null. This could get workarounded by putting the line into an own, tiny
|
||
shell script. Hit CTRL\-c to terminate the command and get the measure output
|
||
displayed.
|
||
|
||
.SH REFERENCES
|
||
"BIOS and Kernel Developer’s Guide (BKDG) for AMD Family 14h Processors"
|
||
http://support.amd.com/us/Processor_TechDocs/43170.pdf
|
||
|
||
"Intel® Turbo Boost Technology
|
||
in Intel® Core™ Microarchitecture (Nehalem) Based Processors"
|
||
http://download.intel.com/design/processor/applnots/320354.pdf
|
||
|
||
"Intel® 64 and IA-32 Architectures Software Developer's Manual
|
||
Volume 3B: System Programming Guide"
|
||
http://www.intel.com/products/processor/manuals
|
||
|
||
.SH FILES
|
||
.ta
|
||
.nf
|
||
/dev/cpu/*/msr
|
||
/sys/devices/system/cpu/cpu*/cpuidle/state*/.
|
||
.fi
|
||
|
||
.SH "SEE ALSO"
|
||
powertop(8), msr(4), vmstat(8)
|
||
.PP
|
||
.SH AUTHORS
|
||
.nf
|
||
Written by Thomas Renninger <trenn@suse.de>
|
||
|
||
Nehalem, SandyBridge monitors and command passing
|
||
based on turbostat.8 from Len Brown <len.brown@intel.com>
|