SMP in 5.1 cant deactivate hyperthreading

Steven Hartland killing at barrysworld.com
Thu Jun 12 17:22:42 PDT 2003


---- Original Message ----- 
From: "John-Mark Gurney" <gurney_j at efn.org>
> > Yes 5.X is still new tech and may not run on all machines but on the ones
> > which it does ( and it runs very well here ) basic tools are required. If
> > it doesn't run on a machine your under know false impressions, if however
> > you users complain of performance issues and you look @ top and it says
> > 50% idle and its really 0% idle its a different matter.
> 
> That's a good way to remind the admin to turn the cpu back on.

Don't by it there just checking sysctl is easy enough.

> Now is there any good reason why you need to keep the cpu disabled?

Its disabled by default due to performance reasons and we keep it that
way. We are talking hyperthreading, logical CPU's, not real physical CPU's.
Its quite easy to see if CPU's are disabled as mentioned above. If you check
the release notes for top then you'll see a similar fix had to be made for sunos5
in beta5 iirc.

    Steve 



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