I think Linus might have referred to my 'future plans' entry:
| Future plans:
| - there's ongoing work to reduce 1Hz to 0Hz, to essentially shut
| off the periodic tick altogether when there's a single busy task on a
| CPU. We'd first like 1 Hz to be exposed more widely before we go for
| the 0 Hz target though.
| - once we reach 0 Hz we can and remove the periodic tick assumption from
| nr_running>=2 as well, by essentially interrupting busy tasks only as
| frequently as the sched_latency constraints require us to do - once
| every 4-40 msecs, depending on nr_running.
and indicated that in practice desktop and developer workload will see the
full win from reduced HZ only once we implement those two points and
extend the scope of dynticks even more and make HZ truly variable
regardless of rq->nr_running