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

[Bill Davidsen <davidsen@tmr.com>]

Maurice wrote:
> Denis Vlasenko <vda@port.imtp.ilyichevsk.odessa.ua> 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@tmr.com)
"The secret to procrastination is to put things off until the
  last possible moment - but no longer"  -me