Re: BFS vs. mainline scheduler benchmarks and measurements

[Jens Axboe]

On Mon, Sep 07 2009, Ingo Molnar wrote:
> 
> * Jens Axboe <jens.axboe@xxxxxxxxxx> wrote:
> 
> > On Mon, Sep 07 2009, Jens Axboe wrote:
> > > Scheduler       Runtime         Max lat     Avg lat     Std dev
> > > ----------------------------------------------------------------
> > > CFS             100             951         462         267
> > > CFS-x2          100             983         484         308
> > > BFS
> > > BFS-x2
> > 
> > Those numbers are buggy, btw, it's not nearly as bad. But 
> > responsiveness under compile load IS bad though, the test app just 
> > didn't quantify it correctly. I'll see if I can get it working 
> > properly.
> 
> What's the default latency target on your box:
> 
>   cat /proc/sys/kernel/sched_latency_ns
> 
> ?

It's off right now, but it is set to whatever is the default. I don't
touch it.

> And yes, it would be wonderful to get a test-app from you that would 
> express the kind of pain you are seeing during compile jobs.

I was hoping this one would, but it's not showing anything. I even added
support for doing the ping and wakeup over a socket, to see if the pipe
test was doing well because of the sync wakeup we do there. The net
latency is a little worse, but still good. So no luck in making that app
so far.

-- 
Jens Axboe

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