Re: It hurts when I shoot myself in the foot

[Alan Cox]

> Couldn't that be solved in one of the following ways?
> 
> 1) Disable pre-emption while reading TSC and CPU nr.
> 2) Use affinity for processes pre-empted in kernel mode.
> 3) Disable pre-emption for SMP systems.

You can solve it by disabling pre-emption (and given its questionable
value doing so permanently might not be a bad idea). However if you simply
disable pre-emption during udelay() calls then you've just screwed yourself
by removing 99% of the use pre-emption had.

Given all the pain its probably better to not use the TSC