Re: another must-fix: major PS/2 mouse problem

[Albert Cahalan <albert@users.sf.net>]

On Sat, 2003-07-26 at 11:16, Zwane Mwaikambo wrote:
> On Fri, 25 Jul 2003, Andrew Morton wrote:
> 
> > But did your instrumentation account for nested interrupts?  What happens
> > if a slow i8042 interrupt happens in the middle of a 3c59x interrupt?
> 
> Just to verify that, he could remove the local_irq_enable for 
> !SA_INTERRUPT.

OK, I did this. Now, in microseconds, I get:

------------------------
IRQ use      min     max
--- -------- --- -------   
  0 timer     40  103968
  1 i8042     14    1138 (was 389773)
  2 cascade    -       -
  3 -          -       -
  4 serial    29      56
  5 uhci-hcd   -       -
  6 -        690     690
  7 -         40      40
  8 -          -       -
  9 -          -       -
 10 -          -       -
 11 eth0      73   31332 (was 1535331)
 12 i8042     18     215 (was 102895)
 13 -          -       -
 14 ide0       7   43846
 15 ide1       7      12 
------------------------
   
boomerang_interrupt itself takes 4 to 59 microseconds.

Then I switched to 2.6.0-test2. Testing more, I get the
problem with or without SMP and with or without
preemption. Here's a chunk of my log file:

Loosing too many ticks!
TSC cannot be used as a timesource. (Are you running with SpeedStep?)
Falling back to a sane timesource.
psmouse.c: Lost synchronization, throwing 3 bytes away.
psmouse.c: Lost synchronization, throwing 1 bytes away.

Arrrrgh! The TSC is my only good time source!

Remember that this is a pretty normal system. I have
a Red Hat 8 install w/ required upgrades, ext3, IDE,
a 1-GHz Pentium III, a boring VIA chipset, etc.

To reproduce, I do some PS/2 mouse movement while
doing one of:

a. Lots of concurrent write() and sync() activity to ext3.
b. Lots of NFSv3 traffic.