Re: why kernel implement "udelay" by cpu instructions?

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On Mon, Nov 2, 2009 at 8:43 AM, loody <miloody@xxxxxxxxx> wrote:
Dear all:
I find the kernel use cpu instruction to implement the udelay function
as keeping decrease a big counter by 1.

Actually this is not a CPU instruction, its basically a "timer"  which is scaled at hardware level according to Frequency of Processsor(CPU).

If I search the right place in kernel, why kernel does so?
the precision will be different if cpu runs faster or slower, right?
appreciate your help,
miloody

it does not depend on how faster & slower cpu, if CPU is faster then it scaled down more.
Its implemented as different block in Processor, as timer, not on cpu counter,  if we use processeor counter then it slow down the processor by giving many interrupts..
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