[$] Fixing SCHED_IDLE

The Linux kernel scheduler is a complicated beastand a lot of effort goes into improving it during every kernel releasecycle. The 5.4 kernel release includes a few improvements to the existingSCHED_IDLE scheduling policy that can help users improve thescheduling latency of their high-priority (interactive) tasks if they usethe SCHED_IDLE policy for the lowest-priority (background)tasks. Read on for a description of this work contributed by Viresh Kumar.