Not to beat a dead horse, but ...

[John-Mark Gurney]

George Mitchell wrote this message on Sun, Jun 08, 2014 at 14:15 -0400:
> When I run this command on 10-STABLE on a uniprocessor system while
> running the misc/dnetc port:
> 
> cd /usr/src
> time make buildworld && time make buildkernel && time make installkernel
> 
> On revision 266422 with SCHED_ULE, I get (showing the time lines only):
> 
> 7045.988u 897.681s 4:00:33.89 55.0%     29430+492k 27927+17003io 
> 30943pf+519w
> 1155.683u 149.422s 52:49.60 41.1%       25418+410k 7452+20843io 12166pf+248w
> 7.101u 4.838s 8:03.57 2.4%      5905+221k 1179+9461io 1345pf+67w
> 
> On revision 267211 with SCHED_4BSD:
> 
> 6950.087u 665.074s 2:40:36.19 79.0%     29929+502k 33651+17368io 
> 31151pf+151w
> 1148.066u 134.312s 26:40.95 80.1%       26234+426k 9681+24613io 11917pf+106w
> 6.774u 4.369s 0:33.90 32.8%     3110+320k 1388+10979io 1514pf+3w
> 
> Since the majority of my systems are uniprocessors and I like to
> run dnetc, SCHED_ULE has been a dealbreaker for me since day one.
> Consequently I can't use freebsd_update.
> 
> The party line seems to be, "Well, everybody knows SCHED_ULE sucks
> on uniprocessors."  Hello?  Not everybody has upgraded to multiple
> core or hyperthreaded processors yet.  Do we really want to write
> off every uniprocessor piece of hardware out here?
> 
> The other assertion I hear is that SCHED_ULE really excels on some
> unspecified workload or other.  I'd love to see exactly how much
> better it does than 4BSD on these mythological loads.    -- George

Were you running dnetc at the same time as buildworld?  If you are,
then did you also measure how much work dnetc did durning the same
period of time?

If you were running dnetc, your complaint is that one processor
hog wasn't able to hog the processor as much as another processor
hog?  If the numbers above are to be believed, _ULE is doing a
better job than _4BSD since it more evenly shared the processor
w/ the other processor hog, in that they both got ~50% of the
cpu...  If this is the case, then you need to use nice w/ buildworld
to give it higher priority...

Also, you did not say if you've applied the various sysctl changes
that have been suggested on the mailing list...

-- 
  John-Mark Gurney				Voice: +1 415 225 5579

     "All that I will do, has been done, All that I have, has not."