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.

Please note that this SBo doesn't have any sources in the DOWNLOAD
setting, as the sources are already part of a full slackware install.

Optional dependencies: audit, numactl
Another optional dependency is libunwind, but it's unsupported for now
since it requires elfutils which we don't have yet on SBO.
