2.4.x: spinlock problem

[Ulrich Windl]

Hello,

I had reported this before: In 2.4.0 getting exact system time from 
interrupt handlers seems inaccurate (in 2.2.18 it works fine). I have 
applied the same modifications to the 2.4 code base as to 2.2.

With 2.4.1 the kernel is incredibly slow, so you can watch the 
individual lines of kernel boot be printed on the screen.

I checked the spinlocks, but could not find a problem. Before I start 
removing the new spinlocks for timer, PIC and RTC, I'd like to hear 
what the gurus might think.

I also tried to find out how I can profile the kernel or trace the 
spinlocks, but that seems to be hardly documented.

Any hints?

Regards,
Ulrich