Re: 2.6.xSMP and IPv4 issues (ifconfig(s))

[Bill Davidsen]

Maurice wrote:
> Denis Vlasenko <vda@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
>
> > You should connect your box to another one and verify that
> > network is ok (it is working under non-SMP kernel, right?).
> > Most probably you already did this. :)
> >
> > Then, do this ping test again, and while ping is running, do
> >
> > tcpdump -nleieth0 -s0 -vvv
> >
> > on both boxes. You will see what is happening on the wire.
> > For example, does other box actually hear anything?
> >
> >
> > > New! Netscape Toolbar for Internet Explorer
> >
> > Heh.
> > --
> > vda
>
>
> Not to switch gears on you, but...
>
> I have a "fix", through some feedback from the fedora-legacy-project list I was directed to send the command 'noapic' at boot time.  To see if this would have some effect on the IPv4 problem.
>
> This allowed IPv4 to operate with the SMP kernel!!!
>
> So, can anyone explane what is going on with this...
> Is it my motherboard/bios having communication issues with the SMP kernel, but not with the non-SMP kernel?

I suspect that the on-CPU interrupt controllers are not getting 
initialized correctly. Using noapic can slow the communication between 
processors, although I've never been able to measure it.

--
   -bill davidsen (davidsen@xxxxxxx)
"The secret to procrastination is to put things off until the
 last possible moment - but no longer"  -me
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