cvs commit: src/sys/amd64/amd64 mp_machdep.c src/sys/i386/i386 mp_machdep.c

[Colin Percival]

Maxim Sobolev wrote:
> For what it is worth I think Nate has the correct point. We should not
> force this setting upon each and every user if it can realistically
> affect only 0.0001% of our userbase.

We're not forcing anything -- it's configurable via loader.conf.  All
we're talking about is changing the default value.

> By the way, I wonder how sun4v (aka Niagara) fares in this respect. As
> long as I know, they use similar concept, when 8 physical cores can run
> 32 threads. Should we disable it by default there as well? ;-)

I haven't seen any experiments done on sun4v, but I'm less concerned about
it since I believe sun4v boxes are used more often for large computing jobs
rather than for interactive logins with many untrusted users.  Of course,
if/when we have scheduler support for keeping different users on separate
cores, this should be applied to sun4v as well.

Colin Percival