Messages in this thread | | | Date | Thu, 9 Oct 2003 00:43:40 +0100 | From | Jamie Lokier <> | Subject | Re: [PATCH] Poll-based IDE driver |
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Alan Cox wrote: > On Mer, 2003-10-08 at 13:14, Srivatsa Vaddagiri wrote: > > 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.
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