2.6.24 says "serial8250: too much work for irq4" a lot.

[Rob Landley <rob@landley.net>]

When running a 2.6.24 kernel built for x86-64 under qemu via serial console, 
doing CPU-intensive things that also produce a lot of output (such as 
compiling software) tends to produce the error message in the title.

Anybody have a clue why?  It doesn't seem to cause an actual problem, but it's 
kind of annoying.

(If it's a qemu issue, I can go bother them.  It's possible that qemu isn't 
delivering interrupts as often as it expects, since that's limited by the 
granularity of the host timer; I know the clock in qemu can run a bit slow 
because it only gets clock interrupts when the host system isn't too busy to 
schedule the emulator.  But this doesn't usually cause a problem.  I _think_ 
the message is just a "this should never happen" type warning, which is 
happening to me.  But I break stuff. :)

Rob
-- 
"One of my most productive days was throwing away 1000 lines of code."
  - Ken Thompson.