Questions on the scheduler

Kris Kennaway kris at
Sat Sep 29 10:24:48 PDT 2007

Abdullah Ibn Hamad Al-Marri wrote:
> On 9/29/07, Kris Kennaway <kris at> wrote:
>> Oliver Herold wrote:
>>> Are there any numbers or technical papers? Just out of curiosity.
>> I ran a mysql benchmark against Dragonfly-current and FreeBSD 7 on an
>> 8-core machine (one of the workloads that FreeBSD now performs very well
>> at) and found 0 scaling on dragonfly.  Their developers confirmed that
>> the kernel is still entirely giant locked (as in FreeBSD 4) so no SMP
>> performance benefits are possible.
>> The email thread is here:
>> although the linked graph is offline.  The FreeBSD curve was essentially
>> this one (FreeBSD has improved further since then):
>> with dragonfly a flat line at ~500 tps independent of load.
>> Kris
> How does NetBSD, and OpenBSD scale when it comes to SMP comparing to
> FreeBSD 7.0?

I was unable to boot NetBSD reliably on my hardware (the serial console 
only worked about 1/8 of the time) and did not even bother with OpenBSD 
because there is no reason to think they will be a contender for 

One of the NetBSD developers recently posted a comparison on old 
4*pentium 3 hardware, but their numbers are highly suspicious to me 
since they are way out of line with what I have measured on similar 
FreeBSD systems.  I am waiting to hear back from him about it.


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