Re: [PATCH rt-tests 2/2] oslat: Use cpuset size as upper bound

[Peter Xu <peterx@redhat.com>]

On Wed, Feb 10, 2021 at 11:28:16PM -0500, John Kacur wrote:
> 
> 
> On Wed, 10 Feb 2021, Daniel Wagner wrote:
> 
> > To assign the threads to the correct CPU we need to use the cpuset
> > size as upper bound for the loop and not the number of threads.
> > 
> > Fixes: 85b0763dacd9 ("oslat: Use parse_cpumask() from rt-numa.h")
> > Reported-by: Peter Xu <peterx@redhat.com>
> > Signed-off-by: Daniel Wagner <dwagner@suse.de>
> > ---
> >  src/oslat/oslat.c | 7 +++++--
> >  1 file changed, 5 insertions(+), 2 deletions(-)
> > 
> > diff --git a/src/oslat/oslat.c b/src/oslat/oslat.c
> > index d3f659b218b0..62b82098419a 100644
> > --- a/src/oslat/oslat.c
> > +++ b/src/oslat/oslat.c
> > @@ -742,9 +742,12 @@ int main(int argc, char *argv[])
> >  	n_cores = numa_bitmask_weight(cpu_set);
> >  
> >  	TEST(threads = calloc(1, n_cores * sizeof(threads[0])));
> > -	for (i = 0; i < n_cores; ++i)
> > -		if (numa_bitmask_isbitset(cpu_set, i) && move_to_core(i) == 0)
> > +	for (i = 0; n_cores && i < cpu_set->size; i++) {
> > +		if (numa_bitmask_isbitset(cpu_set, i) && move_to_core(i) == 0) {
> >  			threads[g.n_threads_total++].core_i = i;
> > +			n_cores--;
> > +		}
> > +	}
> >  
> >  	if (numa_bitmask_isbitset(cpu_set, 0) && g.rtprio)
> >  		printf("WARNING: Running SCHED_FIFO workload on CPU 0 may hang the thread\n");
> > -- 
> > 2.30.0
> > 
> > 
> 
> This looks okay, but we are waiting for Pradipta's testing to confirm 
> before I push it.

After the reporter's confirmation there seems to have two issues.  Daniel's
patch should be a valid fix of at least one of the problem.  The other problem
is still under investigation and I think it's not affecting the upstream
branch.  So I think we don't need to wait for that anymore:

Reviewed-by: Peter Xu <peterx@redhat.com>
Tested-by: Peter Xu <peterx@redhat.com>

Thanks,

-- 
Peter Xu