On Monday 28 May 2007, Thomas Gleixner wrote:
quoted text
> 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=3Doff nohz=3Doff (should be the same as your working confi=
g)
quoted text
> > > 2) highres=3Doff
> > > 3) nohz=3Doff
> >
> > I tested this with my 2.6.22-rc3 kernel, here are the results:
> >
> > without any special boot parameters: problem does appear
> > highres=3Doff nohz=3Doff: problem does not appear
> > highres=3Doff: problem does not appear
> > nohz=3Doff: problem does appear
>
> Is there any other strange behavior of the high res enabled kernel than
> the b44 problem ?

I didn't notice anything.

quoted text
>
> > 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=20
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=20
some time. With this driver and High Resolution Timer turned on I get=20
problems using iperf. The problems are that the systems becomes really slow=
=20
and unresponsive.  Michael Buesch thought this could be an IRQ storm which=
=20
sounds logical to me. This bug did never happen to me before I startet the=
=20
iperf test.

The other issue happens only with 2.6.22-rc2-mm1 which includes the b44 ssb=
=20
spilt. It's independed wether High Resolution Timer is turned on or off I=20
always get very varying and high ping times. The iperf-test doesn't show th=
e=20
problems from 2.6.21/22-rc3.

Maxi