Please explain.

Julian Elischer julian at
Sun Sep 19 00:51:38 PDT 2004

I never saw this email from timh so I'm replying to this reply instead..

> --- timh at wrote:
>> processor affinity design issue..  
>>i.e.. processes stay on the cpu they are
>>spawned on..which is a big problem for mysql which explains why it
>>performs better on other systems.

yes We ALL know what processor affinity is.
What makes you say we have not done anything aout this.?

We have are working on a new scheduler (ULE) that is designed to
implement processor affinity as a basic part of its functionality.
When we are happy wih it we'll make it standard.

>>Furthermore, the SMP issue is a common problem among many FreeBSD
>>developers whom have told me the same, there is alot of this 
 >>information all over the
>>internet. FreeBSD is unable to perform good on multiple CPUs, 
 >>the fixes are just work arounds.

What have they told you? SMP in FreeBSD is coming along quite nicely
as far as I see.. We now have native SMP scaleable threading
in the default system, and larger and larger parts of the system
ara able to take advantage of Multiple processors to parallelise their

>>Unless if the freebsd community has just started to fix the
>>multithreading issue, it's a huge problem.

We've been working hard at it for 4 years (where did you get 6?)
and we are seeing real results..  It sounds to me like you haven't
actually tried it out yet. We hav elots to do yet,
but there's been a lot of progress.

BTW there is something going on with linux and mysql..
It looks like they have some optimisations in there that are not SMP
related as their uniprocessor numbers are also better, and I've
heard that when you run a linux mysql binary under freeBSD you
also get similar improvements so
My money is on the compile options or something ;-)

>> Darwin does not 

>>have this problem whatsoever.

Dawin was designed from the beginning for SMP. Mach was SMP capable from the
firt release I ever worked on which was 2.0.

>>Why do I care? This is a silly question. I have 2 windows PCs here, I
>>have 9
>>other workstations that all run unix. I am a server manager and I do
>>consulting work for freebsd/linux. Windows came free so why not? I
>>don't do business on it.

>>I've been a really huge FreeBSD supporter.. but I am really concerned
>>about this issue which has been an issue for so long.

I suggest that you follow what is actually going on rather than listenning to
"the internet".

>>tim h.


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