Re: [PATCH RFC 5/7] selftests/sched: Add SCHED_DEADLINE bandwidth tests to kselftest

[Juri Lelli]

On 11/03/26 09:31, Christian Loehle wrote:
> On 3/6/26 16:10, Juri Lelli wrote:

...

> > +	/* Start one cpuhog per CPU at max bandwidth */
> > +	printf("  Starting %d cpuhog tasks at max bandwidth...\n", num_cpus);
> > +
> > +	for (i = 0; i < num_cpus; i++) {
> > +		pids[i] = dl_create_cpuhog(runtime_ns, deadline_ns, period_ns, 0);
> > +		if (pids[i] < 0) {
> > +			printf("  Task %d failed to start: %s\n",
> > +			       i + 1, strerror(errno));
> > +			goto cleanup;
> > +		}
> > +		started++;
> > +	}
> 
> Would it be okay to just have one task per max-cap CPU to make this pass on HMP?
> Or something more sophisticated?
> 

On HMP we should probably have max bandwidth hogs on big CPUs and then
scale runtime (bandwidth) considering smaller CPUs capacities. Cannot
quickly check atm, but that info (max cap per-CPU) is available
somewhere in sys or proc, is it?

Thanks,
Juri