Re: [rt-tests v1 4/6] cyclictest: Mimik --smp behavior with --affinity

[John Kacur <jkacur@redhat.com>]

On Fri, 18 Dec 2020, Daniel Wagner wrote:

> Let --affinity without an argument behave in the same way as
> --smp. Run a thread on each CPU. This makes cyclictest behave as the
> rest of the rt-tests when --affinity is used.
> 
> Reviewed-by: Daniel Wagner <dwagner@suse.de>
> ---
>  src/cyclictest/cyclictest.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/src/cyclictest/cyclictest.c b/src/cyclictest/cyclictest.c
> index 0e6519125c2f..b9b0eb3575e3 100644
> --- a/src/cyclictest/cyclictest.c
> +++ b/src/cyclictest/cyclictest.c
> @@ -1024,6 +1024,8 @@ static void process_options(int argc, char *argv[], int max_cpus)
>  				    argv[optind][0] == '0' ||
>  				    argv[optind][0] == '!')) {
>  				parse_cpumask(argv[optind], max_cpus, &affinity_mask);
> +			} else {
> +				num_threads = -1;
>  			}
>  
>  			if (verbose)
> -- 
> 2.29.2
> 
> 
Well, --smp historically combined -a -t and threads at the same priority
You could argue that it is reasonable for -a to automatically imply -t
but I have had debates with people about this and we settled on -a just 
specifies the affinity, and the default number of threads is one unless
you use -t.

I'm not sure what you mean by this makes cyclictest behave the way the 
rest of rt-tests does, the rest of rt-tests should match what cyclitest 
does. That said, I did some quick runs of signaltest and -a seems broken,
sigh.