Alan Cox wrote:

On Mer, 2003-10-08 at 13:14, Srivatsa Vaddagiri wrote:

quoted

Since my code is supposed to run when system is crashing, I would like 
to avoid calling any function in the kernel as far as possible, since 
the kernel and its data structures may be in a inconsistent state 
and/or corrupted.

For x86 udelay is a tiny piece of code - you could easily inline it

No, because that changes the delay.  Things like whether the
instructions straddle a cache line or page boundary, or ar 4-byte or
16-byte aligned affect the timing on some x86 CPUs.

udelay must reside at a fixed memory location to get the nearest thing
to determinism that we know how to get.

-- Jamie