BCC - Tools for BPF-based Linux IO analysis, networking, monitoring, and more
BCC - Tools for BPF-based Linux IO analysis, networking, monitoring, and more
BCC is a toolkit for creating efficient kernel tracing and manipulation programs, and includes several useful tools and examples. It makes use of extended BPF (Berkeley Packet Filters), formally known as eBPF, a new feature that was first added to Linux 3.15. Much of what BCC uses requires Linux 4.1 and above.
eBPF was described by Ingo Molnár as:
One of the more interesting features in this cycle is the ability to attach eBPF programs (user-defined, sandboxed bytecode executed by the kernel) to kprobes. This allows user-defined instrumentation on a live kernel image that can never crash, hang or interfere with the kernel negatively.
BCC makes BPF programs easier to write, with kernel instrumentation in C (and includes a C wrapper around LLVM), and front-ends in Python and lua. It is suited for many tasks, including performance analysis and network traffic control.
This example traces a disk I/O kernel function, and populates an in-kernel power-of-2 histogram of the I/O size. For efficiency, only the histogram summary is returned to user-level.
…
The above output shows a bimodal distribution, where the largest mode of 800 I/O was between 128 and 255 Kbytes in size.
See the source: bitehist.py. What this traces, what this stores, and how the data is presented, can be entirely customized. This shows only some of many possible capabilities.
See INSTALL.md for installation steps on your platform.
See FAQ.txt for the most common troubleshoot questions.
See docs/reference_guide.md for the reference guide to the bcc and bcc/BPF APIs.
Some of these are single files that contain both C and Python, others have a pair of .c and .py files, and some are directories of files.