Re: ULE/SCHED_SMP diff for 7.0, buildkernel & thanks.

From: <youshi10_at_u.washington.edu>
Date: Tue, 17 Jul 2007 12:41:58 -0700 (PDT)
On Tue, 17 Jul 2007, Attilio Rao wrote:

> 2007/7/17, Abdullah Ibn Hamad Al-Marri <almarrie_at_gmail.com>:
>> 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?
>
> Just look at the link Jeff posted, it seems very well explaining :).
>
> Attilio
>
>
> -- 
> Peace can only be achieved by understanding - A. Einstein

Unfortunately those results are still based on 2.6.20, not 2.6.22 (2 minor patch revision difference).

I assume that that's for a vanilla Linux kernel?

-Garrett
Received on Tue Jul 17 2007 - 17:41:59 UTC

This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:39:14 UTC