HTT/SMP
Stephen Montgomery-Smith
stephen at math.missouri.edu
Tue Mar 1 00:55:41 GMT 2005
Kris Kennaway wrote:
> On Mon, Feb 28, 2005 at 06:39:21PM -0600, Stephen Montgomery-Smith wrote:
>
>>I have a dual Xeon system, for which I had hyperthreading enabled. I
>>was running a CPU intensive floating point program (specifically using
>>the fftw3 port with threads). I found that using 4 (hyper) processors
>>really did give me a speed advantage, even though I do find web sites
>>that suggested this advantage was minimal. (So for example, 4 processes
>>on this system seemed to run at the equivalent of 2GHz on these 3GHz
>>computers, so the advantage was about 1.3 times.)
>>
>>But then after about a day the computer had a panic. I found that 4
>>CPU's under FreeBSD 5.3 is apparently unstable, and there were
>>statements to the effect that this would be fixed in FreeBSD 5.4. Is
>>this going to happen? I am currently running a rather recent version of
>>FreeBSD 5.3-Stable, maybe a week or two old, so I am concerned that
>>maybe this won't get committed.
>
>
> Depends on the panic. What was it?
>
> Kris
I'm sorry, but I didn't write it down. Something about a page being
messed up or something. Since I had already seen messages to the effect
that HTT on dual processors had problems, I assumed that it was just
that. I can tell you that I now have HTT disabled, and it is not
panicing at all.
Was there some fix committed (which would suggest that maybe this is
some other problem)? If so, I could reenable HTT and wait for another
panic to occur, and then write it down.
Thanks, Stephen
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