tools/power/cpupower/man/cpupower-monitor.1 - linux - Git at Google

 .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 interval.
 .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

 .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"
 https://support.amd.com/us/Processor_TechDocs/43170.pdf

 "What Is Intel® Turbo Boost Technology?"
 https://www.intel.com/content/www/us/en/gaming/resources/turbo-boost.html

 "Power Management - Technology Overview"
 https://cdrdv2.intel.com/v1/dl/getContent/637748

 "Intel® 64 and IA-32 Architectures Software Developer's Manual
 Volume 3B: System Programming Guide"
 https://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>
	.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 interval.
	.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

	.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"
	https://support.amd.com/us/Processor_TechDocs/43170.pdf

	"What Is Intel® Turbo Boost Technology?"
	https://www.intel.com/content/www/us/en/gaming/resources/turbo-boost.html

	"Power Management - Technology Overview"
	https://cdrdv2.intel.com/v1/dl/getContent/637748

	"Intel® 64 and IA-32 Architectures Software Developer's Manual
	Volume 3B: System Programming Guide"
	https://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>