perf is a userspace interface to the kernel's perf events. Performance
counters are CPU hardware registers that count hardware events
such as instructions executed, cache-misses suffered, or branches
mispredicted. They form a basis for profiling applications to trace
dynamic control flow and identify hotspots.

Optional dependencies: audit, numactl, libunwind

Please note that this build doesn't have any sources in the .info
file, as the sources are already part of the Slackware kernel-source
package. Your running kernel's version should match the kernel-source
version. If it doesn't:

- If your kernel source is located in /usr/src/linux-$VERSION, you
  can export KERNEL=<version> in the script's environment. Example:

  export KERNEL=4.4.240

- If your kernel source is somewhere else, you can export
  KERNEL=</path/to/source>. Example:

  export KERNEL=/home/myuser/kernels/linux-4.2.240

Please note that the package's version number will match the version
of the kernel source, *not* necessarily what's in the perf.info file.
