[LTP] [PATCH] sched/starvation: Choose from available cpus

[Edward Liaw]

On Wed, Jun 5, 2024 at 4:39 PM Wei Gao <wegao@suse.com> wrote:
>
> On Wed, Jun 05, 2024 at 06:05:36PM +0000, Edward Liaw via ltp wrote:
> > Use the first available cpu in the sched_getaffinity set.
> >
> > This test was failing as a 32bit test for some arm architectures where
> > cpu 0 does not support 32bit applications.
> >
> > Signed-off-by: Edward Liaw <edliaw@google.com>
> > ---
> >  .../kernel/sched/cfs-scheduler/starvation.c     | 17 ++++++++++++++++-
> >  1 file changed, 16 insertions(+), 1 deletion(-)
> >
> > diff --git a/testcases/kernel/sched/cfs-scheduler/starvation.c b/testcases/kernel/sched/cfs-scheduler/starvation.c
> > index eb9fd6ff5..e0ea30d19 100644
> > --- a/testcases/kernel/sched/cfs-scheduler/starvation.c
> > +++ b/testcases/kernel/sched/cfs-scheduler/starvation.c
> > @@ -49,13 +49,28 @@ again:
> >  static void setup(void)
> >  {
> >       cpu_set_t mask;
> > +     int cpu = 0;
> > +     long ncpus = tst_ncpus_conf();
> >
> >       CPU_ZERO(&mask);
> >
> > -     CPU_SET(0, &mask);
> > +     /* Restrict test to a single cpu */
> > +     TST_EXP_POSITIVE(sched_getaffinity(0, sizeof(mask), &mask));
> s/TST_EXP_POSITIVE/TST_EXP_PASS

Will do.

> > +
> > +     if (CPU_COUNT(&mask) == 0)
> > +             tst_brk(TCONF, "No cpus available");
> I suppose this should a bug happen if cpu count is 0, so i suggest
> s/TCONF/TBROK. What do you think?

Yeah that makes more sense.  Will send a v2.

>
> > +
> > +     while (CPU_ISSET(cpu, &mask) == 0 && cpu < ncpus)
> > +             cpu++;
> > +
> > +     CPU_ZERO(&mask);
> > +
> > +     CPU_SET(cpu, &mask);
> >
> >       TST_EXP_POSITIVE(sched_setaffinity(0, sizeof(mask), &mask));
> s/TST_EXP_POSITIVE/TST_EXP_PASS
> >
> > +     tst_res(TINFO, "Set affinity to CPU %d", cpu);
> > +
> >       if (tst_parse_long(str_loop, &loop, 1, LONG_MAX))
> >               tst_brk(TBROK, "Invalid number of loop number '%s'", str_loop);
> >
> Others LGTM. Thanks for your nice patch!

Thanks!