NAME

psst - Power Stress and Shaping Tool

SYNOPSIS

psst [options <value>]

DESCRIPTION

The Power Stress and Shaping Tool (PSST) is a controlled power 'virus' for Intel SoC components such as CPU and GPU.
The objective is to subject the SoC at different run-time-varying utilization levels for analysis. This is done by controlled duty-cycling of utilization to specific contour. A simplest contour could be fixed low utilization. This allows simple usage, such as logging of system parameters at fixed low overhead even at small polling intervals (ms). More complex usage, such as study of governors, workloads e.t.c., are possible by applying different power shape contours and options.

OPTIONS

-C --cpumask CPUMASK

CPUMASK is hexadecimal bit mask of cpu selected. (e.g., a1 selects cpu 0, 5, 7. default: every online cpu, maximum 1024)

-p --poll-period pollperiod

pollperiod specifies period for logging in milliseconds (default 500 ms)

-d --duration m

specifies duration m in milliseconds to run psst (default is 3600000; 1 hour)

-l --log-file path

specifies the full path to the logfile (default is /var/log/psst.csv)

-v --verbose

enables verbose mode (default: disabled when args specified)

-V --version

prints version

-T --track-max-cpu

Track the cpu# with maxed freq during poll period

-h --help

prints help

-s --shape-func shape-func,arg

Specifies power shape function and argument:

Shape Function	Argument
single-step,v	where v is load step height [C0%]. (default shape: single-step,0.1)
sinosoid,w,a	where w is wavelength [seconds] and a is the amplitude (max load %)
stair-case,v,u	where v is load step height [C0%], u is step length (sec)
single-pulse,v,u	where v is load step height [C0%], u is step length (sec)
linear-ramp,m	where m is the slope (load/sec)
saw-tooth,m,a	slope m (load/sec); reversed after max a% or min(0.1)%

EXAMPLES

1.: Use psst just for logging various power/thermal parameters:

sudo psst # same as $./psst -s single-step,0.1 -p 500 -v

2.: Linear ramp CPU power with slope 3% usage-per-sec applied for cpu 1 and 3, polling and reporting every 700mS, output on termial, running for 33 seconds:

sudo psst -s linear-ramp,3 -C a -p 700 -d 33000 -v

AUTHOR

Started by Noor Mubeen

COPYRIGHT

Copyright © 2017, Intel Corporation License GPLv2: GNU GPL version 2
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Or, say, there is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.