2.2.1 (possibly others as well): loosing 2 ticks even under light load

Ulrich Windl (ulrich.windl@rz.uni-regensburg.de)
Fri, 5 Mar 1999 09:06:02 +0100


Hello, a notifier:

For debugging purposes I added a print statement to show lost ticks
in the i386 kernel. On my Pentium 100 even for very light load the
kernel declares having lost 2 ticks.

I don't know why this happend, but I see a problem: If the kernel
looses 2 ticks on a light load, it might loose more ticks on heavy
load. Unfortunately the non-TSC version of the timeoffset routine
(using the timer chip's register) can only span one tick, possibly
guessing that there's more than one, but not more.

Therefore losing over 1 tick might cause a bad time.

I have no idea how to find the parts that disable interrupts for that
long...

Regards,
Ulrich

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