Re: How to measure time accurately.

[Chris Friesen]

krishna wrote:
> Hi All,
>
> Can any one tell me how to measure time accurately for a block of C code 
> in device drivers.
> For example, If I want to measure the time duration of firmware download.

Most cpus have some way of getting at a counter or decrementer of 
various frequencies.  Usually it requires low-level hardware knowledge 
and often it needs assembly code.


On ppc you'd use the mftbu/mftbl instructions, as suggested by Lee on 
x86 you'd use the rdtsc instruction.

Chris
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