Re: Improved UDP performance using 2.6.21-rc5-rt10
From: dave_sperry@xxxxxxxx
Date: Tue Apr 03 2007 - 09:26:44 EST
rt10 shows a big improvement over rt8
##################################################
etup Thruput CPU%
Nvidia
2.6.21-rc5-rt8 938 65%
netperf @51
hardirq @50
softirq @50
Nvidia
2.6.21-rc5-rt10 938 32%
netperf @51
hardirq @50
softirq @50
very nice for a "work in progress"
I ran the netperf test a few times and one of the times the netperf test would no longer talk to the server. I had to reboot the rt client to get netperf to talk again. I did have cycle soak running which may have contributed to the problem.
Also when netperf is not running the hard IRQs associated with the NIC use a constant 2% load.
Thanks,
Dave
-------------- Original message ----------------------
From: Ingo Molnar <mingo@xxxxxxx>
>
> * David Sperry <dave_sperry@xxxxxxxx> wrote:
>
> > > there are a few other things i'm working on to improve this. I've
> > > uploaded -rt9 which is the current state of affairs. Note that using
> > > -rt9 you'll likely only see IRQ-8406 overhead in the system, because
> > > i've added an optimization to do process the softirq-net-tx workload
> > > in the hardirq thread if the priority of the two is the same (which
> > > is the default behavior). But -rt9 is still work in progress that is
> > > not fully finished yet: in some cases i'm seeing 'fluctuating
> > > performance' problems on forcedeth that werent there before.
> >
> > I tried -rt9 and saw some odd 'fluctuating performance'. I'll try it
> > again tomorrow when I am much closer to the box's power button.
>
> could you try -rt10? I've improved hardirq/softirq threading performance
> some more, and have tuned the forcedeth driver too.
>
> Ingo
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