Subject: Re: Bad count of CPUs -- On Hyper Threading
To: None <current-users@NetBSD.org>
From: Joseph A. Dacuma <jadacuma@ched.gov.ph>
List: current-users
Date: 10/12/2006 20:56:54
> On Thu, Oct 12, 2006 at 04:01:40AM +0800, Joseph A. Dacuma wrote:
>>
>> Is it wise to enable HT? I came across various sites where they say
>> Hyper
>> Threading makes a system unstable.
>
> s/unstable/slow/
>
> Unless your scheduler completely understands HT, and assigns processes
> accordingly, and unless all the idle loops and busy-wait loops are
> HT correct, you could easily be better off disabling HT.
>
> To some extent HT is a win under windows because its scheduler is so bad
> at handling spinning processes.
>
> 	David
>
Dear Sirs,

Thank you very much for all the info on HT. My last question is, does
NetBSD completely understand HT? Or will one be better off disabling it
completely since the performance gains is not that glaring compared to the
risks involved when enabled for common systems.