ULE/SCHED_SMP diff for 7.0, buildkernel & thanks.

[Abdullah Ibn Hamad Al-Marri]

On 7/17/07, Jeff Roberson <jroberson at chesapeake.net> wrote:
> With regards to buildkernel times;  I do not want to sacrafice performance
> on other benchmarks to improve buildkernel.  The problem is that 4BSD is
> as agressive as possible at scheduling work on idle cores.  This behavior
> that helps one buildworld hurts on other, in my opinion, more important
> benchmarks.
>
> For example: http://people.freebsd.org/~jeff/sysbench.png
>
> ULE is 33% faster than SCHED_4BSD at this mysql test.  This is a direct
> result of prefering to idle to make more efficient scheduling decisions.
> ULE is also faster at various networking benchmarks for similar reasons.
>
> I also believe that while the real time may be slower on buildworld the
> system and user time will be smaller by a degree greater than the delta in
> real time.  This means that while you're building packages you have a
> little more cpu time leftover to handle other tasks.  Furthermore, as the
> number of cores goes up things start to tip in favor of ULE although this
> is somewhat because it's harder for even 4BSD to keep them busy due to
> disk bandwidth.
>
> Thanks everyone for testing.  Can someone confirm that they have tested
> with x86 rather than amd64?  I will probably commit later today.
>
> Thanks,
> Jeff

Did you compare it to latest Linux fixes? is FreeBSD + ULE + MySQL
still faster than linux?



-- 
Regards,

-Abdullah Ibn Hamad Al-Marri
Arab Portal
http://www.WeArab.Net/