fdmonbench - File Descriptor Monitoring Benchmark

Collect performance results for Linux file descriptor monitoring APIs.

The benchmark sends a message to one or more threads that monitor for file descriptor activity. When a file descriptor becomes readable the message is read and sent back as a reply. The next message is sent to a random file descriptor when the reply is received.

This ping-pong test simulates an application that is monitoring one or more file descriptors and one of them becomes ready at a time.

Supported APIs:

• select(2)
• poll(2)
• epoll(7)
• io_uring
• io_uring AIO (for comparison with kernel asynchronous I/O)
• threads (for comparison with threaded architectures)

Metrics

• Duration (seconds) - wall clock time, may vary slightly from the desired duration
• Total Roundtrips - number of times a message was sent and a reply was received
• Roundtrips/second - the main performance metric, indicating the rate at which messages were transferred
• CPU usage (seconds) - total user and system CPU usage of the benchmark process
• Roundtrips/CPU seconds - efficiency metric, indicating how many messages are transferred per unit of CPU time

Usage

$ fdmonbench
Usage: fdmonbench [OPTION]...
Perform file descriptor monitoring benchmarking.

  --duration-secs=<int>  run for number of seconds (default: 30)
  --engine=epoll|io_uring|io_uring-aio|poll|select|threads
                         set fd monitoring engine (default: select)
  --exclusive=0|1        use EPOLLEXCLUSIVE (default: 0)
  --help                 print this help
  --msg-size             number of bytes per message (default: 1)
  --num-engines          number of engine instances (default: 1)
  --num-fds              number of file descriptors (default: 1)

This software is licensed under the GNU General Public License v3.0 or later.

Please contact Stefan Hajnoczi stefanha@gmail.com for questions about this software.