Re: [LTP] [PATCH 4/8][RT] matrix_mult.c: better prio and scheduler settings

[Timothy R. C. <tim...@li...>]

Hi Gilles,

On Thu, 2008-10-16 at 11:22 +0200, Gilles Carry wrote:
> Before doing any disk I/O, put back thread to SCHED_OTHER/prio 0.
> ---
>  testcases/realtime/func/matrix_mult/matrix_mult.c |   13 ++++++++-----
>  1 files changed, 8 insertions(+), 5 deletions(-)
> 
> diff --git a/testcases/realtime/func/matrix_mult/matrix_mult.c b/testcases/realtime/func/matrix_mult/matrix_mult.c
> index 18c3e47..3576427 100644
> --- a/testcases/realtime/func/matrix_mult/matrix_mult.c
> +++ b/testcases/realtime/func/matrix_mult/matrix_mult.c
> @@ -75,10 +75,6 @@ stats_container_t shist, chist;
>  static pthread_barrier_t mult_start;
>  static pthread_mutex_t mutex_cpu;
> 
> -int gettid(void)
> -{
> -	return syscall(__NR_gettid);
> -}

Does this change belong here?

I'll let someone comment on the rest... looks fine to me though.

> 
>  void usage(void)
>  {
> @@ -283,12 +279,16 @@ void main_thread(void)
>  	/* run matrix mult operation sequentially */
>  	curdat = &sdat;
>  	printf("\nRunning sequential operations\n");
> +	set_priority(PRIO);
>  	start = rt_gettime();
>  	for (i = 0; i < iterations; i++)
>  		matrix_mult_record(MATRIX_SIZE, i);
>  	end = rt_gettime();
>  	delta = (long)((end - start)/NS_PER_US);
> 
> +	/* Go back to normal prio before doing any disk activity */
> +	set_priority_other(0);
> +
>  	savg = delta/iterations; /* don't use the stats record, use the total time recorded */
>  	smin = stats_min(&sdat);
>  	smax = stats_max(&sdat);
> @@ -309,6 +309,7 @@ void main_thread(void)
>  		fprintf(stderr, "Warning: could not save sequential mults stats\n");
>  	}
> 
> +	set_priority(PRIO);
>  	/* Create numcpus-1 concurrent threads */
>  	for (j = 0; j < (numcpus-1); j++) {
>  		tids[j] = create_fifo_thread(concurrent_thread, (void *)(intptr_t)j, PRIO);
> @@ -339,6 +340,9 @@ void main_thread(void)
>  		pthread_mutex_unlock(&t->mutex);
>  	}
> 
> +	/* Go back to normal prio before doing any disk activity */
> +	set_priority_other(0);
> +
>  	cavg = delta/iterations; /* don't use the stats record, use the total time recorded */
>  	cmin = stats_min(&cdat);
>  	cmax = stats_max(&cdat);
> @@ -406,7 +410,6 @@ int main(int argc, char *argv[])
>  		printf("jvmsim disabled\n");
>  	}
> 
> -	set_priority(PRIO);
>  	main_thread();
> 
>  	join_threads();
-- 
-tim