[post-factum]

Setting the nice level is not enough. Instead, `SCHED_IDLE` policy should be applied to the workload that is being run in the background.

[1] may help if you run such a workload from CLI.

[1] https://codeberg.org/post-factum/litter

[arakageeta]

SCHED_IDLE is problematic. There is no priority inheritance with SCHED_OTHER threads. SCHED_OTHER threads block for prolonged periods of time when they contend for a mutex in the kernel with a SCHED_IDLE thread. The SCHED_IDLE thread holds the mutex, but it is unable to complete its critical section because it keeps getting preempted.