Re: Time measuring on an SBC2440-II (ARM920T) board

["Ravi Sankar" <ravisankar.g@xxxxxxxxx>]

>I try to measure the execution time of a function in a c program. With
>the header "sys/time.h" it is possible to measure the time in
>microseconds, but I need more precise information.

>Is there a way to read out the clock count of the processor or to
>access the timers under arm linux?

To get the accurate time consumed by the function use clock() instead of
gettimeifday().
gettimeofday() gives you wall clock time elapsed instead of execution time
of a function.
To get the value in micro sec use below code

pseudo code to get function() execution time
------------------------------------------------------
#include <clock.h>
#define NLOOP 1000000
clock_t c0, c1;
double i, time_in_micro;

co =clock();

for(i=0; i< NLOOP; i++)
      function();

c1 = clock();

time_in_micro = (c1 - c0)*(1/CLOCK_PER_SEC);

--------------------------------------------------------

Hope this helps you.
Ravi Sankar Guntur.

On Fri, Nov 28, 2008 at 8:10 PM, Malte Wienecke <Malte.Wienecke@xxxxxx>wrote:

> Hi,
>
> I try to measure the execution time of a function in a c program. With
> the header "sys/time.h" it is possible to measure the time in
> microseconds, but I need more precise information.
>
> Is there a way to read out the clock count of the processor or to
> access the timers under arm linux?
>
> I hope you can help me.
>
>
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-- 
--,
BR,
Ravi Sankar Guntur.
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