Re: b44: regression in 2.6.22 (resend)

Gary Zambrano
2007-05-29T15:21:39Z

On Mon, 2007-05-28 at 13:55 -0700, Maximilian Engelhardt wrote:
> On Monday 28 May 2007, Thomas Gleixner wrote:
> > On Mon, 2007-05-28 at 19:44 +0200, Maximilian Engelhardt wrote:
> > > > Can you please keep CONFIG_HIGH_RES_TIMERS and CONFIG_NOHZ and try the
> > > > following combinations on the kernel command line:
> > > >
> > > > 1) highres=off nohz=off (should be the same as your working config)
> > > > 2) highres=off
> > > > 3) nohz=off
> > >
> > > I tested this with my 2.6.22-rc3 kernel, here are the results:
> > >
> > > without any special boot parameters: problem does appear
> > > highres=off nohz=off: problem does not appear
> > > highres=off: problem does not appear
> > > nohz=off: problem does appear
> >
> > Is there any other strange behavior of the high res enabled kernel than
> > the b44 problem ?
>
> I didn't notice anything.
>
> >
> > > I additionally built my 2.6.22-rc2-mm1 kernel without High Resolution
> > > Timer, but the high ping problem is still there.
> >
> > Hmm, that's mysterious. Wild guess is that highres exposes the hidden
> > "feature" in a different way than rc2-mm1 does.
>
> I think the bug in 2.6.21/22-rc3 is a different one that the one in
> 2.6.22-rc2-mm1, but that's also only a wild guess :)
>
> I'll explain this a bit:
> In 2.6.21/22-rc3 is the same b44 driver that has been in the stock kernels for
> some time. With this driver and High Resolution Timer turned on I get
> problems using iperf. The problems are that the systems becomes really slow
> and unresponsive. Michael Buesch thought this could be an IRQ storm which
> sounds logical to me. This bug did never happen to me before I startet the
> iperf test.

Can you please check to see if you notice anything out of the ordinary
using netperf in place of iperf in your high res timer on/off testbed?

Thanks,
Gary