c2adb1877b
System-wide TSC read could cause a drift in C0 percentage calculation.
Because if first TSC is read and then one by one mperf is read for all
cpus, this introduces drift between mperf reading of later CPUs and TSC
reading. To lower this drift read TSC per CPU and also just after mperf
read. This technique improves C0 percentage calculation in Mperf monitor.
Before fix: (System 100% busy)
| Mperf || RAPL || Idle_Stats
PKG|CORE| CPU| C0 | Cx | Freq || pack | core || POLL | C1 | C2
0| 0| 0| 87.15| 12.85| 2695||168659003|3970468|| 0.00| 0.00| 0.00
0| 0| 256| 84.62| 15.38| 2695||168659003|3970468|| 0.00| 0.00| 0.00
0| 1| 1| 87.15| 12.85| 2695||168659003|3970468|| 0.00| 0.00| 0.00
0| 1| 257| 84.08| 15.92| 2695||168659003|3970468|| 0.00| 0.00| 0.00
0| 2| 2| 86.61| 13.39| 2695||168659003|3970468|| 0.00| 0.00| 0.00
0| 2| 258| 83.26| 16.74| 2695||168659003|3970468|| 0.00| 0.00| 0.00
0| 3| 3| 86.61| 13.39| 2695||168659003|3970468|| 0.00| 0.00| 0.00
0| 3| 259| 83.60| 16.40| 2695||168659003|3970468|| 0.00| 0.00| 0.00
0| 4| 4| 86.33| 13.67| 2695||168659003|3970468|| 0.00| 0.00| 0.00
0| 4| 260| 83.33| 16.67| 2695||168659003|3970468|| 0.00| 0.00| 0.00
0| 5| 5| 86.06| 13.94| 2695||168659003|3970468|| 0.00| 0.00| 0.00
0| 5| 261| 83.05| 16.95| 2695||168659003|3970468|| 0.00| 0.00| 0.00
0| 6| 6| 85.51| 14.49| 2695||168659003|3970468|| 0.00| 0.00| 0.00
After fix: (System 100% busy)
| Mperf || RAPL || Idle_Stats
PKG|CORE| CPU| C0 | Cx | Freq || pack | core || POLL | C1 | C2
0| 0| 0| 98.03| 1.97| 2415||163295480|3811189|| 0.00| 0.00| 0.00
0| 0| 256| 98.50| 1.50| 2394||163295480|3811189|| 0.00| 0.00| 0.00
0| 1| 1| 99.99| 0.01| 2401||163295480|3811189|| 0.00| 0.00| 0.00
0| 1| 257| 99.99| 0.01| 2375||163295480|3811189|| 0.00| 0.00| 0.00
0| 2| 2| 99.99| 0.01| 2401||163295480|3811189|| 0.00| 0.00| 0.00
0| 2| 258|100.00| 0.00| 2401||163295480|3811189|| 0.00| 0.00| 0.00
0| 3| 3|100.00| 0.00| 2401||163295480|3811189|| 0.00| 0.00| 0.00
0| 3| 259| 99.99| 0.01| 2435||163295480|3811189|| 0.00| 0.00| 0.00
0| 4| 4|100.00| 0.00| 2401||163295480|3811189|| 0.00| 0.00| 0.00
0| 4| 260|100.00| 0.00| 2435||163295480|3811189|| 0.00| 0.00| 0.00
0| 5| 5| 99.99| 0.01| 2401||163295480|3811189|| 0.00| 0.00| 0.00
0| 5| 261|100.00| 0.00| 2435||163295480|3811189|| 0.00| 0.00| 0.00
0| 6| 6|100.00| 0.00| 2401||163295480|3811189|| 0.00| 0.00| 0.00
0| 6| 262|100.00| 0.00| 2435||163295480|3811189|| 0.00| 0.00| 0.00
Cc: Thomas Renninger <trenn@suse.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Fixes:
|
||
|---|---|---|
| .. | ||
| bench | ||
| debug | ||
| lib | ||
| man | ||
| po | ||
| utils | ||
| .gitignore | ||
| cpupower-completion.sh | ||
| Makefile | ||
| README | ||
| TODO | ||
The cpupower package consists of the following elements:
requirements
------------
On x86 pciutils is needed at runtime (-lpci).
For compilation pciutils-devel (pci/pci.h) and a gcc version
providing cpuid.h is needed.
For both it's not explicitly checked for (yet).
libcpupower
----------
"libcpupower" is a library which offers a unified access method for userspace
tools and programs to the cpufreq core and drivers in the Linux kernel. This
allows for code reduction in userspace tools, a clean implementation of
the interaction to the cpufreq core, and support for both the sysfs and proc
interfaces [depending on configuration, see below].
compilation and installation
----------------------------
make
su
make install
should suffice on most systems. It builds libcpupower to put in
/usr/lib; cpupower, cpufreq-bench_plot.sh to put in /usr/bin; and
cpufreq-bench to put in /usr/sbin. If you want to set up the paths
differently and/or want to configure the package to your specific
needs, you need to open "Makefile" with an editor of your choice and
edit the block marked CONFIGURATION.
THANKS
------
Many thanks to Mattia Dongili who wrote the autotoolization and
libtoolization, the manpages and the italian language file for cpupower;
to Dave Jones for his feedback and his dump_psb tool; to Bruno Ducrot for his
powernow-k8-decode and intel_gsic tools as well as the french language file;
and to various others commenting on the previous (pre-)releases of
cpupower.
Dominik Brodowski