SMP performance on drgonfly

Kris Kennaway kris at
Fri May 18 17:32:28 PDT 2007

On Fri, May 18, 2007 at 04:46:27PM -0700, Matthew Dillon wrote:
>     A large chunk of the kernel still runs under the big giant
>     lock, including the light weight processes that libthread_xu
>     uses, so something like mysql is going to hit a lot of BGL
>     contention.

Oh, OK.

What subsystems are out from under the big giant lock, so I can look
for another benchmark to compare with?  Also, what profiling and
contention measurement tools do you have, so I can try to confirm that
this is the issue?

>     You may be able to get DragonFly to run on the machines you
>     were having problems with by compiling it with SMP but 
>     without APIC_IO.  With that combination DragonFly will use
>     the PIC in SMP mode, which usually works.

The issue is that I cannot even install with a UP kernel, so I can't
recompile to test this.  I posted with more details about this problem
a few months ago.

>     I'd use 1.8 for any testing, or 1.9 Preview.


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