VPP/cpel
From fd.io
CPEL Performance Event Log Files
This page describes the CPEL file format. Over the last decade, we've constructed a set of tools to collect, display and report fine-grained performance event data. As the toolset has grown, limitations inherent in previous file formats have become an issue.
CPEL files consist of a set of sections, similar to ELF-files. Specific tools may or may not understand a particular section. Sections are TLV's: (tag, length, value) tuples. Specific tools can skip or copy sections without needing to know anything about the data therein.