Re: sched: Move SCHED_DEBUG sysctl to debugfs

Christian Borntraeger
2021-04-27T15:00:32Z

Peter,

I just realized that we moved away sysctl tunabled to debugfs in next.
We have seen several cases where it was benefitial to set
sched_migration_cost_ns to a lower value. For example with KVM I can
easily get 50% more transactions with 50000 instead of 500000.
Until now it was possible to use tuned or /etc/sysctl.conf to set
these things permanently.

Given that some people do not want to have debugfs mounted all the time
I would consider this a regression. The sysctl tunable was always
available.

I am ok with the "informational" things being in debugfs, but not
the tunables. So how do we proceed here?

Christian