/ 
Linux-libperf-Simple-1.001
/ Linux::libperf::Simple

NAME

Linux::libperf::Simple - simple wrapper around libperf

SYNOPSIS

use Linux::libperf::Simple;

my $p = Linux::libperf::Simple->new;
$p->enable;
# perform in-process task to measure
$p->disable;
my $result = $p->results;

DESCRIPTION

This module is a simple wrapper around Linux libperf.

It is intended for use in measuring in-process execution time for precise benchmarking, whether it will actually be useful for that remains to be seen.

You will need to install the package (Redhat-ish) or build from source (Debian-ish at this time). libperf is supplied as part of the Linux source tree, it is not theonewolf/libperf from Github.

To build from source extract the linux sources, the more recent the better:

cd tools/lib/perf
make prefix=/where/to/install install

To actually use this module you will either need to be root, or kernel.perf_event_paranoid may need to be set to a lower value than the default, look this up before using it.

METHODS

new()

Create a new object, no parameters (yet).

enable()
disable()

Enable or disable stats collection.

You can enable and disable multiple times. Statistics are cumulative.

results()

Returns a hash reference where the keys are (intended to be) the keys used by the perf tool, and the values are each a hash ref with the following possible keys (some are currently never used):

  • val - the value of the captured statistic

  • enabled

  • id

  • lost

  • run

EXPORTABLE FUNCTIONS

run(CODEREF)
use Linux::libperf::Simple "run";
my $results = run(sub { code to check });

Run CODEREF and returning the timing from running it. Returns a hashref as per results() above.

report(CODEREF)
use Linux::libperf::Simple "report";
report(sub { code to check });

Run CODEREF and produces a simple report to standard output.

TROUBLESHOOTING

Unfortunately libperf's reporting isn't very good, if libperf fails to initialize try using strace to see details on which system call actually failed, eg you might try:

strace -o trace.txt perl -MLinux::libperf::Simple=run -e 'run(sub {})'

and look over trace.txt to see why it failed.

BUGS

Everything is subject to change.

AUTHOR

Tony Cook <tony@develop-help.com>