Your subject is wrong; this is 100% a sched patch.
On Fri, Jan 22, 2021 at 04:11:57AM +0800, wu860403-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org wrote:
From: Liming Wu <redacted>
Now we can rely on PSI to reflect whether there is contention in
the task group, but it cannot reflect the details of the contention.
Through this metric, we can get avg latency of task group contention
from the dimension of scheduling.
delta(wait_usec)/delta(nr_waits)
Only if all tasks have the same weight. So in general this is useless.
Also change wait_sum to wait_usec.
Also patches should do 1 thing, also you can't do that, you'll break
everybody that expect the current value.