Interbench

Interbench is a cool benchmark application made specifically to test how well Linux handles interactivity. It's all about figuring out how changes in the Linux kernel or system settings impact performance, like when you tweak the I/O scheduler, CPU settings, or filesystem options. By running these benchmarks carefully, you can compare different hardware setups.

How Interbench Works

This tool is designed to mimic how CPU scheduling works for interactive tasks and measures things like scheduling latency and jitter. It first runs tests with just the tasks on their own. Then it adds in various background loads—this can be adjusted using nice levels, and yes, those benchmarked tasks can even be real-time!

Reproducing CPU Usage

The first step is to find out the best way to maintain a fixed percentage of CPU usage on the machine doing the benchmarking. This information gets saved into a file so that it can keep things consistent for all future runs.

Measuring Latency

Interbench kicks off a high-priority timing thread that wakes up the simulated interactive tasks when needed. It measures how long it takes for those tasks to get scheduled after waking up. Since Linux doesn't have super accurate timer-driven scheduling, this timing thread sleeps as accurately as possible within what the Linux kernel supports. The latency is measured from this sleep until the task actually gets scheduled.

Separate Processes for Each Simulation

Each benchmark simulation runs as its own process with its unique threads, which means any background load also operates separately. This setup helps ensure that you get clear results from your testing.

If you're ready to try out Interbench, head over to SoftPas for more details!