Re: [PATCH v4] sched/topology: Enable topology_span_sane check only for debug builds

[Naman Jain]

On 3/6/2025 10:18 PM, Valentin Schneider wrote:
> On 06/03/25 11:23, Naman Jain wrote:
> > diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
> > index c49aea8c1025..666f0a18cc6c 100644
> > --- a/kernel/sched/topology.c
> > +++ b/kernel/sched/topology.c
> > @@ -2359,6 +2359,13 @@ static bool topology_span_sane(struct sched_domain_topology_level *tl,
> >   {
> >        int i = cpu + 1;
> >
> > +	/* Skip the topology sanity check for non-debug, as it is a time-consuming operation */
> > +	if (!sched_debug()) {
> > +		pr_info_once("%s: Skipping topology span sanity check. Use `sched_verbose` boot parameter to enable it.\n",
> > +			     __func__);
>
> FWIW I'm not against this change, however if you want to add messaging
> about sched_verbose I'd put that in e.g. sched_domain_debug() (as a print
> once like you've done here) with something along the lines of:
>
>    "Scheduler topology debugging disabled, add 'sched_verbose' to the cmdline to enable it"


Thank you so much for reviewing.
Please correct me if I misunderstood. Are you proposing below change?

--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -2361,7 +2361,7 @@ static bool topology_span_sane(struct 
sched_domain_topology_level *tl,

        /* Skip the topology sanity check for non-debug, as it is a 
time-consuming operation */
        if (!sched_debug()) {
-               pr_info_once("%s: Skipping topology span sanity check. 
Use `sched_verbose` boot parameter to enable it.\n",
+               pr_info_once("%s: Scheduler topology debugging disabled, 
add 'sched_verbose' to the cmdline to enable it\n",
                             __func__);
                return true;
        }


Regards,
Naman

> > +		return true;
> > +	}
> > +
> >        /* NUMA levels are allowed to overlap */
> >        if (tl->flags & SDTL_OVERLAP)
> >                return true;
> > --
> > 2.34.1