default or selected kernelversion does not have config value CONFIG_RCU_PERF_TEST_RUNNABLE.
Result is shown for kernelversion 5.4.33

performance tests for RCU runnable by default

configname: CONFIG_RCU_PERF_TEST_RUNNABLE

Linux Kernel Configuration
└─>RCU Debugging
└─>performance tests for RCU runnable by default
In linux kernel since version 4.7 (release Date: 2016-07-24)  
This option provides a way to build the RCU performance tests
directly into the kernel without them starting up at boot time.
You can use /sys/module to manually override this setting.
This /proc file is available only when the RCU performance
tests have been built into the kernel.

Say Y here if you want the RCU performance tests to start during
boot (you probably don't).
Say N here if you want the RCU performance tests to start only
after being manually enabled via /sys/module.