Commit Graph

45 Commits

Author SHA1 Message Date
Kristen Carlson Accardi ca58710f3a tools/power turbostat: display C8, C9, C10 residency
Display residency in the new C-states, C8, C9, C10.

C8, C9, C10 are present on some:
"Fourth Generation Intel(R) Core(TM) Processors",
which are based on Intel(R) microarchitecture code name Haswell.

Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2013-04-17 19:23:26 -04:00
Len Brown 149c2319c6 tools/power turbostat: additional Haswell CPU-id
There is an additional HSW CPU-id, 0x46,
which has C-states exactly like CPU-id 0x45.

Signed-off-by: Len Brown <len.brown@intel.com>
2013-03-15 11:05:26 -04:00
Len Brown 1ed51011af tools/power turbostat: display SMI count by default
The SMI counter is popular -- so display it by default
rather than requiring an option.  What the heck,
we've blown the 80 column budget on many systems already...

Note that the value displayed is the delta
during the measurement interval.
The absolute value of the counter can still be seen with
the generic 32-bit MSR option, ie.  -m 0x34

Signed-off-by: Len Brown <len.brown@intel.com>
2013-02-13 18:22:12 -05:00
Len Brown 6792041834 tools/power turbostat: decode MSR_IA32_POWER_CTL
When verbose is enabled, print the C1E-Enable
bit in MSR_IA32_POWER_CTL.

also delete some redundant tests on the verbose variable.

Signed-off-by: Len Brown <len.brown@intel.com>
2013-02-08 19:26:16 -05:00
Len Brown 70b43400bc tools/power turbostat: support Haswell
This patch enables turbostat to run properly on the
next-generation Intel(R) Microarchitecture, code named "Haswell" (HSW).

HSW supports the BCLK and counters found in SNB.

Signed-off-by: Len Brown <len.brown@intel.com>
2013-02-08 19:25:57 -05:00
Linus Torvalds 6842d98de7 Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux
Pull powertool update from Len Brown:
 "This updates the tree w/ the latest version of turbostat, which
  reports temperature and - on SNB and later - Watts."

Fix up semantic merge conflict as per Len.

* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux:
  tools: Allow tools to be installed in a user specified location
  tools/power: turbostat: make Makefile a bit more capable
  tools/power x86_energy_perf_policy: close /proc/stat in for_every_cpu()
  tools/power turbostat: v3.0: monitor Watts and Temperature
  tools/power turbostat: fix output buffering issue
  tools/power turbostat: prevent infinite loop on migration error path
  x86 power: define RAPL MSRs
  tools/power/x86/turbostat: share kernel MSR #defines
2012-12-18 12:34:29 -08:00
Josh Boyer 55f1f545f7 tools: Allow tools to be installed in a user specified location
When building x86_energy_perf_policy or turbostat within the confines of
a packaging system such as RPM, we need to be able to have it install to
the buildroot and not the root filesystem of the build machine.  This
adds a DESTDIR variable that when set will act as a prefix for the
install location of these tools.

Signed-off-by: Josh Boyer <jwboyer@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2012-11-30 01:09:45 -05:00
Mark Asselstine ee0778a301 tools/power: turbostat: make Makefile a bit more capable
The turbostat Makefile is pretty simple, its output is placed in the
same directory as the source, the install rule has no concept of a
prefix or sysroot, and you can set CC to use a specific compiler but
not use the more familiar CROSS_COMPILE. By making a few minor changes
these limitations are removed while leaving the default behavior
matching what it used to be.

Example build with these changes:
make CROSS_COMPILE=i686-wrs-linux-gnu- DESTDIR=/tmp install

or from the tools directory
make CROSS_COMPILE=i686-wrs-linux-gnu- DESTDIR=/tmp turbostat_install

Signed-off-by: Mark Asselstine <mark.asselstine@windriver.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2012-11-30 01:09:45 -05:00
Colin Ian King 84764a415c tools/power x86_energy_perf_policy: close /proc/stat in for_every_cpu()
Instead of returning out of for_every_cpu() we should break out of the loop=
 which will then tidy up correctly by closing the file /proc/stat.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2012-11-30 01:09:44 -05:00
Len Brown 889facbee3 tools/power turbostat: v3.0: monitor Watts and Temperature
Show power in Watts and temperature in Celsius
when hardware support is present.

Intel's Sandy Bridge and Ivy Bridge processor generations support RAPL
(Run-Time-Average-Power-Limiting).  Per the Intel SDM
(Intel® 64 and IA-32 Architectures Software Developer Manual)
RAPL provides hardware energy counters and power control MSRs
(Model Specific Registers).  RAPL MSRs are designed primarily
as a method to implement power capping.  However, they are useful
for monitoring system power whether or not power capping is used.

In addition, Turbostat now shows temperature from DTS
(Digital Thermal Sensor) and PTM (Package Thermal Monitor) hardware,
if present.

As before, turbostat reads MSRs, and never writes MSRs.

New columns are present in turbostat output:

The Pkg_W column shows Watts for each package (socket) in the system.
On multi-socket systems, the system summary on the 1st row shows the sum
for all sockets together.

The Cor_W column shows Watts due to processors cores.
Note that Core_W is included in Pkg_W.

The optional GFX_W column shows Watts due to the graphics "un-core".
Note that GFX_W is included in Pkg_W.

The optional RAM_W column on server processors shows Watts due to DRAM DIMMS.
As DRAM DIMMs are outside the processor package, RAM_W is not included in Pkg_W.

The optional PKG_% and RAM_% columns on server processors shows the % of time
in the measurement interval that RAPL power limiting is in effect on the
package and on DRAM.

Note that the RAPL energy counters have some limitations.

First, hardware updates the counters about once every milli-second.
This is fine for typical turbostat measurement intervals > 1 sec.
However, when turbostat is used to measure events that approach
1ms, the counters are less useful.

Second, the 32-bit energy counters are subject to wrapping.
For example, a counter incrementing 15 micro-Joule units
on a 130 Watt TDP server processor could (in theory)
roll over in about 9 minutes.  Turbostat detects and handles
up to 1 counter overflow per measurement interval.
But when the measurement interval exceeds the guaranteed
counter range, we can't detect if more than 1 overflow occured.
So in this case turbostat indicates that the results are
in question by replacing the fractional part of the Watts
in the output with "**":

Pkg_W  Cor_W GFX_W
  3**    0**   0**

Third, the RAPL counters are energy (Joule) counters -- they sum up
weighted events in the package to estimate energy consumed.  They are
not analong power (Watt) meters.  In practice, they tend to under-count
because they don't cover every possible use of energy in the package.
The accuracy of the RAPL counters will vary between product generations,
and between SKU's in the same product generation, and with temperature.

turbostat's -v (verbose) option now displays more power and thermal configuration
information -- as shown on the turbostat.8 manual page.
For example, it now displays the Package and DRAM Thermal Design Power (TDP):

cpu0: MSR_PKG_POWER_INFO: 0x2f064001980410 (130 W TDP, RAPL 51 - 200 W, 0.045898 sec.)
cpu0: MSR_DRAM_POWER_INFO,: 0x28025800780118 (35 W TDP, RAPL 15 - 75 W, 0.039062 sec.)
cpu8: MSR_PKG_POWER_INFO: 0x2f064001980410 (130 W TDP, RAPL 51 - 200 W, 0.045898 sec.)
cpu8: MSR_DRAM_POWER_INFO,: 0x28025800780118 (35 W TDP, RAPL 15 - 75 W, 0.039062 sec.)

Signed-off-by: Len Brown <len.brown@intel.com>
2012-11-30 01:09:44 -05:00
Len Brown ddac0d6872 tools/power turbostat: fix output buffering issue
In periodic mode, turbostat writes to stdout,
but users were un-able to re-direct stdout, eg.

turbostat > outputfile

would result in an empty outputfile.

Signed-off-by: Len Brown <len.brown@intel.com>
2012-11-30 01:09:43 -05:00
Len Brown e52966c084 tools/power turbostat: prevent infinite loop on migration error path
Turbostat assumed if it can't migrate to a CPU, then the CPU
must have gone off-line and turbostat should re-initialize
with the new topology.

But if turbostat can not migrate because it is restricted by
a cpuset, then it will fail to migrate even after re-initialization,
resulting in an infinite loop.

Spit out a warning when we can't migrate
and endure only 2 re-initialize cycles in a row
before giving up and exiting.

Signed-off-by: Len Brown <len.brown@intel.com>
2012-11-27 00:03:06 -05:00
Len Brown 9c63a650bb tools/power/x86/turbostat: share kernel MSR #defines
Now that turbostat is built in the kernel tree,
it can share MSR #defines with the kernel.

Signed-off-by: Len Brown <len.brown@intel.com>
Cc: x86@kernel.org
2012-11-23 21:40:04 -05:00
Len Brown d91bb17c2a tools/power turbostat: graceful fail on garbage input
When invald MSR's are specified on the command line,
turbostat should simply print an error and exit.

Signed-off-by: Len Brown <len.brown@intel.com>
2012-11-01 00:22:00 -04:00
Len Brown 39300ffb9b tools/power turbostat: Repair Segmentation fault when using -i option
Fix regression caused by commit 8e180f3cb6
(tools/power turbostat: add [-d MSR#][-D MSR#] options to print counter
deltas)

Signed-off-by: Len Brown <len.brown@intel.com>
2012-11-01 00:21:43 -04:00
Len Brown f9240813e6 tools/power/turbostat: add option to count SMIs, re-name some options
Counting SMIs is popular, so add a dedicated "-s" option to do it,
and juggle some of the other option letters.

-S is now system summary (was -s)
-c is 32 bit counter (was -d)
-C is 64-bit counter (was -D)
-p is 1st thread in core (was -c)
-P is 1st thread in package (was -p)

bump the minor version number

Signed-off-by: Len Brown <len.brown@intel.com>
2012-10-06 15:26:31 -04:00
Len Brown 8e180f3cb6 tools/power turbostat: add [-d MSR#][-D MSR#] options to print counter deltas
# turbostat -d 0x34
is useful for printing the number of SMI's within an interval
on Nehalem and newer processors.

where
 # turbostat -m 0x34
will simply print out the total SMI count since reset.

Suggested-by: Andi Kleen
Signed-off-by: Len Brown <len.brown@intel.com>
2012-09-27 22:04:56 -04:00
Len Brown 2f32edf12c tools/power turbostat: add [-m MSR#] option
-m MSR# prints the specified MSR in 32-bit format
-M MSR# prints the specified MSR in 64-bit format

Signed-off-by: Len Brown <len.brown@intel.com>
2012-09-26 18:17:21 -04:00
Len Brown 130ff304f6 tools/power turbostat: make -M output pretty
The -M option dumps the specified 64-bit MSR with every sample.

Previously it was output at the end of each line.
However, with the v2 style of printing, the lines are now staggered,
making MSR output hard to read.

So move the MSR output column to the left where things are aligned.

Signed-off-by: Len Brown <len.brown@intel.com>
2012-09-26 18:17:21 -04:00
Len Brown 6574a5d505 tools/power turbostat: print more turbo-limit information
The "turbo-limit" is the maximum opportunistic processor
speed, assuming no electrical or thermal constraints.
For a given processor, the turbo-limit varies, depending
on the number of active cores.  Generally, there is more
opportunity when fewer cores are active.

Under the "-v" verbose option, turbostat would
print the turbo-limits for the four cases
of 1 to 4 cores active.

Expand that capability to cover the cases of turbo
opportunities with up to 16 cores active.

Note that not all hardware platforms supply this information,
and that sometimes a valid limit may be specified for
a core which is not actually present.

Signed-off-by: Len Brown <len.brown@intel.com>
2012-09-26 18:15:48 -04:00
Len Brown d7db690165 tools/power turbostat: delete unused line
MSR_TSC is no longer needed because
we now use RDTSC directly.

Signed-off-by: Len Brown <len.brown@intel.com>
2012-09-26 18:11:48 -04:00
Len Brown 1300651b40 tools/power turbostat: run on IVB Xeon
This fix is required to run on IVB Xeon,
which previously had an incorrect cpuid model number listed.

Signed-off-by: Len Brown <len.brown@intel.com>
2012-09-26 18:11:31 -04:00
Len Brown c3ae331d1c tools/power: turbostat: fix large c1% issue
Under some conditions, c1% was displayed as very large number,
much higher than 100%.

c1% is not measured, it is derived as "that, which is left over"
from other counters.  However, the other counters are not collected
atomically, and so it is possible for c1% to be calaculagted as
a small negative number -- displayed as very large positive.

There was a check for mperf vs tsc for this already,
but it needed to also include the other counters
that are used to calculate c1.

Signed-off-by: Len Brown <len.brown@intel.com>
2012-07-19 22:26:33 -04:00
Len Brown c98d5d9444 tools/power: turbostat v2 - re-write for efficiency
Measuring large profoundly-idle configurations
requires turbostat to be more lightweight.
Otherwise, the operation of turbostat itself
can interfere with the measurements.

This re-write makes turbostat topology aware.
Hardware is accessed in "topology order".
Redundant hardware accesses are deleted.
Redundant output is deleted.
Also, output is buffered and
local RDTSC use replaces remote MSR access for TSC.

From a feature point of view, the output
looks different since redundant figures are absent.
Also, there are now -c and -p options -- to restrict
output to the 1st thread in each core, and the 1st
thread in each package, respectively.  This is helpful
to reduce output on big systems, where more detail
than the "-s" system summary is desired.
Finally, periodic mode output is now on stdout, not stderr.

Turbostat v2 is also slightly more robust in
handling run-time CPU online/offline events,
as it now checks the actual map of on-line cpus rather
than just the total number of on-line cpus.

Signed-off-by: Len Brown <len.brown@intel.com>
2012-07-19 22:26:14 -04:00
Len Brown 650a37f32d tools/power turbostat: fix IVB support
Initial IVB support went into turbostat in Linux-3.1:
553575f1ae
(tools turbostat: recognize and run properly on IVB)

However, when running on IVB, turbostat would fail
to report the new couters added with SNB, c7, pc2 and pc7.
So in scenarios where these counters are non-zero on IVB,
turbostat would report erroneous residencey results.

In particular c7 time would be added to c1 time,
since c1 time is calculated as "that which is left over".

Also, turbostat reports MHz capabilities when passed
the "-v" option, and it would incorrectly report 133MHz
bclk instead of 100MHz bclk for IVB, which would inflate
GHz reported with that option.

This patch is a backport of a fix already included in turbostat v2.

Signed-off-by: Len Brown <len.brown@intel.com>
2012-06-03 23:47:49 -04:00
Len Brown d15cf7c129 tools/power turbostat: fix un-intended affinity of forked program
Linux 3.4 included a modification to turbostat to
lower cross-call overhead by using scheduler affinity:

15aaa34654
(tools turbostat: reduce measurement overhead due to IPIs)

In the use-case where turbostat forks a child program,
that change had the un-intended side-effect of binding
the child to the last cpu in the system.

This change removed the binding before forking the child.

This is a back-port of a fix already included in turbostat v2.

Signed-off-by: Len Brown <len.brown@intel.com>
2012-06-03 23:24:00 -04:00
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
Linus Torvalds 507a03c1cb Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux
This includes initial support for the recently published ACPI 5.0 spec.
In particular, support for the "hardware-reduced" bit that eliminates
the dependency on legacy hardware.

APEI has patches resulting from testing on real hardware.

Plus other random fixes.

* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux: (52 commits)
  acpi/apei/einj: Add extensions to EINJ from rev 5.0 of acpi spec
  intel_idle: Split up and provide per CPU initialization func
  ACPI processor: Remove unneeded variable passed by acpi_processor_hotadd_init V2
  ACPI processor: Remove unneeded cpuidle_unregister_driver call
  intel idle: Make idle driver more robust
  intel_idle: Fix a cast to pointer from integer of different size warning in intel_idle
  ACPI: kernel-parameters.txt : Add intel_idle.max_cstate
  intel_idle: remove redundant local_irq_disable() call
  ACPI processor: Fix error path, also remove sysdev link
  ACPI: processor: fix acpi_get_cpuid for UP processor
  intel_idle: fix API misuse
  ACPI APEI: Convert atomicio routines
  ACPI: Export interfaces for ioremapping/iounmapping ACPI registers
  ACPI: Fix possible alignment issues with GAS 'address' references
  ACPI, ia64: Use SRAT table rev to use 8bit or 16/32bit PXM fields (ia64)
  ACPI, x86: Use SRAT table rev to use 8bit or 32bit PXM fields (x86/x86-64)
  ACPI: Store SRAT table revision
  ACPI, APEI, Resolve false conflict between ACPI NVS and APEI
  ACPI, Record ACPI NVS regions
  ACPI, APEI, EINJ, Refine the fix of resource conflict
  ...
2012-01-18 15:51:48 -08:00
Len Brown 79ba0db69c Merge branches 'einj', 'intel_idle', 'misc', 'srat' and 'turbostat-ivb' into release 2012-01-18 01:15:54 -05:00
Arun Thomas 9b6cf1a012 tools/power turbostat: update fields in manpage
Field names were shortened: "pkg" is now "pk", "core" is now "cr"

Signed-off-by: Arun Thomas <arun.thomas@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-12-15 16:34:20 +01:00
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 e4c0d0e22c tools/power x86_energy_perf_policy: fix print of uninitialized string
Looks like I was going to stick the brand string
in the verbose ouput, but didn't get around to it.

Signed-off-by: Len Brown <len.brown@intel.com>
2011-07-15 23:39:00 -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
Jiri Kosina 07f9479a40 Merge branch 'master' into for-next
Fast-forwarded to current state of Linus' tree as there are patches to be
applied for files that didn't exist on the old branch.
2011-04-26 10:22:59 +02:00
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
Lucas De Marchi 25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
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 eca0bdd326 Merge branches 'turbostat' and 'x86_energy_perf_policy' into tools 2011-01-11 23:06:28 -05:00
Len Brown d5532ee7b4 tools: create power/x86/x86_energy_perf_policy
MSR_IA32_ENERGY_PERF_BIAS first became available on Westmere Xeon.
It is implemented in all Sandy Bridge processors -- mobile, desktop and server.
It is expected to become increasingly important in subsequent generations.

x86_energy_perf_policy is a user-space utility to set the
hardware energy vs performance policy hint in the processor.
Most systems would benefit from "x86_energy_perf_policy normal"
at system startup, as the hardware default is maximum performance
at the expense of energy efficiency.

See x86_energy_perf_policy.8 man page for more information.

Background:

Linux-2.6.36 added "epb" to /proc/cpuinfo to indicate
if an x86 processor supports MSR_IA32_ENERGY_PERF_BIAS,
without actually modifying the MSR.

In March, 2010, Venkatesh Pallipadi proposed a small driver
that programmed MSR_IA32_ENERGY_PERF_BIAS, based on
the cpufreq governor in use.  It also offered
a boot-time cmdline option to override.
http://lkml.org/lkml/2010/3/4/457
But hiding the hardware policy behind the
governor choice was deemed "kinda icky".

In June, 2010, I proposed a generic user/kernel API to
generalize the power/performance policy trade-off.
"RFC: /sys/power/policy_preference"
http://lkml.org/lkml/2010/6/16/399
That is my preference for implementing this capability,
but I received no support on the list.

So in September, 2010, I sent x86_energy_perf_policy.c to LKML,
a user-space utility that scribbles directly to the MSR.
http://lkml.org/lkml/2010/9/28/246

Here is that same utility, after responding to some review feedback,
to live in tools/power/, where it is easily found.

Signed-off-by: Len Brown <len.brown@intel.com>
2011-01-11 23:02:21 -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