On Wed, 19 Jan 2000, Richard B. Johnson wrote:
And my $0.25 - why the shared memory is always reported as 0 bytes? Is it
something mentioned somewhere in FAQs? Please give me directions if it is.
>
> In linux 2.3.39, if the CPU is given up by calling sched_yield(), even
> though the caller may give up the CPU for many milliseconds, `top`
> still shows that the caller is using 99% of the CPU time.
>
> This shows the problem:
>
>
> #include <stdio.h>
> #include <sys/time.h>
> #define MICRO 1e6
> main()
> {
> struct timeval tv;
> double start;
> double stop;
> double total;
> for(;;)
> {
> gettimeofday(&tv, NULL);
> start = ((double) tv.tv_sec * MICRO) + (double) tv.tv_usec;
> sched_yield();
> sched_yield();
> sched_yield();
> sched_yield();
> sched_yield();
> sched_yield();
> sched_yield();
> sched_yield();
> sched_yield();
> sched_yield();
> gettimeofday(&tv, NULL);
> stop = ((double) tv.tv_sec * MICRO) + (double) tv.tv_usec;
> total = stop - start;
> fprintf(stderr,"TT %8.2f us\n", total);
> }
> }
>
> Now sched_yield(), itself, works well. The problem is that the task
> that gave up the CPU is still being 'Charged' for it!
>
> Cheers,
> Dick Johnson
>
> Penguin : Linux version 2.3.39 on an i686 machine (800.63 BogoMips).
>
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.rutgers.edu
> Please read the FAQ at http://www.tux.org/lkml/
>
===========================================================================
Sergey Kubushin aka the Tamer < > The impossible we do immediately.
e-mail: ksi@ksi-linux.com SK320-RIPE < > Miracles require 24-hour notice.
===========================================================================
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Sun Jan 23 2000 - 21:00:21 EST