Date: Wed, 27 Feb 2008 15:13:59 -0500 From: Mike Tancsa <mike@sentex.net> To: Holger Kipp <hk@alogis.com>, freebsd-stable@freebsd.org Subject: Re: [solved!] Re: em very slow, shared irq... on 6.2p8 Message-ID: <200802272016.m1RKG1tl061076@lava.sentex.ca> In-Reply-To: <20080227200923.GA28690@intserv.int1.b.intern> References: <20080227104942.GA14530@intserv.int1.b.intern> <200802271452.m1REqJ6H059687@lava.sentex.ca> <20080227195058.GA27997@intserv.int1.b.intern> <20080227200923.GA28690@intserv.int1.b.intern>
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At 03:09 PM 2/27/2008, Holger Kipp wrote:
>On Wed, Feb 27, 2008 at 08:50:58PM +0100, Holger Kipp wrote:
> > On Wed, Feb 27, 2008 at 09:50:16AM -0500, Mike Tancsa wrote:
> >
> > more details below. as it currently is, polling seems to do
> > the trick, however handling several em-interfaces with the
> > same irq (mind you, it is pci) shouldn't cause delays of
> > up to 1.5 seconds for a simple ping... Therefore I consider
> > using polling for a nearly idle system more a workaround
> > than a solution to this problem :-(
>[...]
> > with msi enabled (via sysctl) I get
> >
> > 33 packets transmitted, 33 packets received, 0% packet loss
> > round-trip min/avg/max/stddev = 1.865/156.421/1339.841/239.375 ms
> >
> > so looks equally bad (I don't consider 30-40 packets a meaningful sample).
> > I don't know if it makes any differences if switched on directly in
> > loader.conf, though.
>
>have now activated msi in loader.conf and get very good results again.
>
>38 packets transmitted, 38 packets received, 0% packet loss
>round-trip min/avg/max/stddev = 0.291/0.425/0.595/0.067 ms
>
>without polling activated. So it was msi after all I needed here.
>Maybe this should go into docu for em or ifconfig?
Hi,
Yes, sorry I should have mentioned, you need to reboot. But
I strongly suggest upgrading to 6.3R as there are a number of em bugs
that are fixed.... Perhaps some IRQ issues as well. But for MSI in
general, I think the Intel guy recommended running that way for the NIC.
---Mike
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