Re: [PATCH] ia64: disable preemption in udelay()

From: Luck, Tony
Date: Thu Dec 15 2005 - 20:04:21 EST


On Thu, Dec 15, 2005 at 02:50:40PM -0800, Luck, Tony wrote:
> This does make the function a bit big for an "inline" though. Does
> it really need to be inline? Do we care how fast our delay loops
> are?

Moving the current slim-line udelay() out of line would save 41 Kbytes
of text in the generic vmlinux, plus making any modules that use
udelay smaller too. Savings run from a 128-160 bytes for drivers
with just one call to a max of 9 Kbytes for qla2xxx.ko.

Being out-of-line would reduce accuracy, but this would only be
significant when the sleep is for a very small number of microseconds.

So if we need to add more code to udelay(), I think that it
should be moved out-of-line too (into arch/ia64/kernel/time.c).

alpha, m68knommu, powerpc and sh64 already have out of line udelay().

-Tony
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