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: NLen Brown <len.brown@intel.com>

MSR_TSC is no longer needed because
we now use RDTSC directly.
Signed-off-by: NLen Brown <len.brown@intel.com>

This fix is required to run on IVB Xeon,
which previously had an incorrect cpuid model number listed.
Signed-off-by: NLen Brown <len.brown@intel.com>

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: NLen Brown <len.brown@intel.com>

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: NLen Brown <len.brown@intel.com>

Initial IVB support went into turbostat in Linux-3.1:
553575f1
(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: NLen Brown <len.brown@intel.com>

Linux 3.4 included a modification to turbostat to
lower cross-call overhead by using scheduler affinity:

15aaa346
(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: NLen Brown <len.brown@intel.com>

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: NLen Brown <len.brown@intel.com>

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: NLen Brown <len.brown@intel.com>

turbostat -s
cuts down on the amount of output, per user request.

also treak some output whitespace and the man page.
Signed-off-by: NLen Brown <len.brown@intel.com>

Signed-off-by: NLen Brown <len.brown@intel.com>

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: NLen Brown <len.brown@intel.com>

dump only the counters which are active
Signed-off-by: NLen Brown <len.brown@intel.com>

Signed-off-by: NJustin P. Mattock <justinmattock@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

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: NThiago Farina <tfransosi@gmail.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

bug could cause false positive on indicating
presence of invarient TSC or APERF support.
Signed-off-by: NThomas Renninger <trenn@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

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: NLen Brown <len.brown@intel.com>