[LTP] [PATCH] sched_football: isolcpus handling

[Petr Vorel]

Hi Attila,

> sched_football expects each player thread is scheduleable
> to all of the physical CPU threads, however for example
> when you are using isolcpus by default you threads are
> not scheduled to some CPU. It leads to the test hangs.
> 591c56b045b2d44a0f4ba1a13545420b23e909b5solved was asimilar issue
nit: missing spaces:
591c56b045b2d44a0f4ba1a13545420b23e909b5 solved was a similar issue
> in realtime/prio-preempt .

> Signed-off-by: Attila Fazekas <afazekas@redhat.com>
> ---
>  .../realtime/func/sched_football/sched_football.c  | 14 +++++++++++++-
>  1 file changed, 13 insertions(+), 1 deletion(-)

> diff --git a/testcases/realtime/func/sched_football/sched_football.c b/testcases/realtime/func/sched_football/sched_football.c
> index 763b41f23..e4ae6a027 100644
> --- a/testcases/realtime/func/sched_football/sched_football.c
> +++ b/testcases/realtime/func/sched_football/sched_football.c
> @@ -133,6 +133,18 @@ void referee(int game_length)
>  	TST_EXP_EXPR(final_ball == 0);
>  }

> +static inline int get_numcpus(void)
> +{
> +	cpu_set_t mask;
> +
> +	CPU_ZERO(&mask);
> +
> +	/* Get the number of cpus accessible to the current process */
> +	sched_getaffinity(getpid(), sizeof(mask), &mask);
> +
> +	return CPU_COUNT(&mask);
> +}

Can't we unify these get_numcpus() functions and move to librttest.[ch]?

Also we have similar code in testcases/kernel/sched/cfs-scheduler/starvation.c
added in 1800e635783b69cacdce9f654ecd730a8f30915b (uses code from
lib/tst_cpu.c), but that's outside of testcases/realtime/, thus let's keep it
untouched.

Kind regards,
Petr

> +
>  static void do_test(void)
>  {
>  	struct sched_param param;
> @@ -140,7 +152,7 @@ static void do_test(void)
>  	int i;

>  	if (players_per_team == 0)
> -		players_per_team = sysconf(_SC_NPROCESSORS_ONLN);
> +		players_per_team = get_numcpus();

>  	tst_atomic_store(0, &players_ready);