Re: Why do so many machines need "noapic"?

[Ingo Oeser <ioe-lkml@rameria.de>]

On Saturday 15 September 2007, Andrew Morton wrote:
> There are 48 bugs in bugzilla which mention "noapic"
> 
> http://bugzilla.kernel.org/buglist.cgi?query_format=advanced&short_desc_type=allwordssubstr&short_desc=&long_desc_type=substring&long_desc=noapic&kernel_version_type=allwordssubstr&kernel_version=&bug_status=NEW&bug_status=REOPENED&bug_status=ASSIGNED&emailassigned_to1=1&emailtype1=substring&email1=&emailassigned_to2=1&emailreporter2=1&emailcc2=1&emailtype2=substring&email2=&bugidtype=include&bug_id=&chfieldfrom=&chfieldto=Now&chfieldvalue=&regression=both&cmdtype=doit&order=Reuse+same+sort+as+last+time&field0-0-0=noop&type0-0-0=noop&value0-0-0=
> 
> And there are 173,000 on the internet ;)
> http://www.google.com/search?hl=en&q=linux+noapic&btnG=Google+Search
> 
> We screwed this pooch a long time ago - years.  Perhaps if some of the many
> noapic users could run a bisection search to work out when it broke we
> could start fixing things.  But they all have a workaround so there's no
> motivation.

I have 2 SMP-Boards and both need noapic. One is from 2001 (AUSUS CUR-DLS),
one is from June 2006 (Gigabyte M57SLI-S4).

There are many reasons:

1. Bugs which have such a simple workaround don't get much attention.

2. Usually SMP boards are used for machines, which just HAVE to work,
   since they have been expensive. These are not consumer boards.

3. I usually had only USB problems (no IRQ), if ommiting noapic.
   USB technology is a cosumer grade technology and enterprise
   grade developers don't have much interest in it (until now?).

4. IRQ routing setup is often a BIOS issue. You might be able
   to fix that by upgrading your BIOS. That often needs a Windows
   tool. Linux people not always (want to) have access to Windows :-)

I reported the all the problems (starting 2001), no developer 
seemed interested.

I can report them against the latest RC6 kernel tomorrow and put them
into bugzilla, if we now REALLY care.


Best Regards

Ingo Oeser