This set of scripts run a benchmark test on the kernel load balancer.

What we analyze is the maximum time the load_balance function takes when called from the newidle_balance (the CPU is about to sleep, then the scheduler calls newidle_balance to try to pick running tasks from other CPUs).

Since the load balancer runs with interrupts disabled, it may impose significant latency times when there are a reasonable big number of CPUs and under the perfect storm.

We use ktest to run the benchmark in several kernel versions and number of CPUs.

Source tree

• configs/: this folder contains the base kernel config files.

• templates/: contains the jinja2 template files.

• scripts/: utility scripts

• repos/: upstream repos submodules.

• lb_bench.py: this is the script that runs the benchmark and saves the the results in a json file.

• gen-kconf.py: generate the configuration filew to use with ktest

• kconf.yml: input data file for the jinja template.

Running

On the host machine:

• git submodule update --init

• ./gen-kconf.py --machine <target-machine-name>

• ./ktest.pl ktest_confs/<ktest-file>