On Sunday 14 July 2002 12:06, rwhron@... wrote:
> > I have recently been experimenting with 2.4.19-rc1-aa2, and it is my
> > understanding that Andrea has his own IRQbalance in this kernel (I am=
not
> > sure exactly when/what version it appeared).
>
> Andrea's irq-balance appeared in 2.4.19pre10aa3.
>
> > At some point I will try netbench with that version with IRQbalance
> > on/off.
>
> That would be great. BTW, was your test netperf or netbench?
Netbench only. Netbench is a CIFS benchmark which happens to generate a=20
resonable amount of network traffic.=20
> > Any chance you could try it with your benchmarks?
>
> Let's see what my benchmarks show with just using the irqrate and
> irqbalance from pre10-jam2 on pre10aa2. Based on that, it will be clea=
rer
> whether my benchmarks are useful for measuring the effect.
>
> > Anyway, I still don't understand how Ingo's IRQbalance is making a
> > difference.
>
> It's apparently subtle. I selected those latency metric differences in=
jam
> and aa because they are large, and aa/jam share mostly the same codebas=
e.
OK, sounds good. I was just thinking, if Andrea's version of irqbalance=20
neither hurts my performance, and helps your performance, than maybe we h=
ave=20
a winnner. But you are right, in your case, the first step is to identif=
y=20
the responsible patch, then we can move to step 2.
> >> networked or loopback?
> >
> > network
>
> Excellent. That's definitely a better environment for measuring IRQs.
> Was the test on a switch?
For Netperf, there is no switch, just point to point to clients. =20
For Netbench, I do have a 2 switchs, vlan'd for 4 network subnets. Each=20
subnet has a Gbps to the server and 12 100Mbps to 12 clients, for a total=
of=20
4 Gbps on the server and 48 clients. =20
> BTW, 2.4.19-pre10-mjc1 had a few metrics that stood apart from most oth=
er
> pre10 kernels. pre10-mjc1 didn't have irqrate or irqbalance. The mjc
> tree is based off Alan Cox tree.
>
> The differences between mjc and ac is greater than the difference betwe=
en
> jam and aa, so may be harder to find. This is an SMP or hardware
> phenomenon as well; my older k6/2 uniprocessor box doesn't have these
> differences. Here are a few of the interesting ones:
Sorry if you mentined this already, but is this being run on the 4-way xe=
on=20
system with the SMP kernel config option? I have a 2-way PIII here, mayb=
e I=20
can get together some results here and we can compare. =20
-Andrew Theurer
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