mpx (mpx.delete@this.nomail.pl) on May 12, 2013 12:04 pm wrote:
>
> It's about supporting cores with different number of threads changing dynamically
> during runtime.

Bullshit.

That's just stupid. Any reasonable SMT will just re-purpose most of the resources for the single thread if there aren't enough threads to actually do SMT.

If Sparc T4 doesn't do that, and instead has a static partitioning based on some system-visible mode, then that is not at all an indication that anybody sane should care. It is an indication of one thing, and one thing only: sparc hardware designers aren't very good, and can't afford the effort to do a better job.

Big surprise.

And guess what? It's not like it's worth spending any effort on it as long as it's just Sparc that has that odd behavior. Yeah, some other variations on that kind of theme (ie big.little) may end up getting more effort put into it, but I don't understand how anybody intelligent would use Sparc as an argument for anything at all. Christ.

Linus