Re: SMP performance on drgonfly

[Erik Wikström <erik-wikstrom@xxxxxxxxx>]

On 2007-05-19 01:58, Kris Kennaway wrote:
> 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.

You should be able to build a new install CD, with the needed kernel 
options, on the computer where you got it running. Check out the 
nrelease framework for more details.

--
Erik Wikström