Re: [PATCH 1/2] sched: topology: Fix topology validation error

[Peter Zijlstra]

On Mon, Aug 25, 2025 at 08:48:29AM +0530, K Prateek Nayak wrote:
> Hello Tim, Vinicius,
> 
> On 8/23/2025 1:44 AM, Tim Chen wrote:
> > --- a/kernel/sched/topology.c
> > +++ b/kernel/sched/topology.c
> > @@ -2394,6 +2394,14 @@ static bool topology_span_sane(const struct cpumask *cpu_map)
> >  	for_each_sd_topology(tl) {
> >  		int tl_common_flags = 0;
> >  
> > +#ifdef CONFIG_NUMA
> > +		/*
> > +		 * sd_numa_mask() (one of the possible values of
> > +		 * tl->mask()) depends on the current level to work
> > +		 * correctly.
> > +		 */
> > +		sched_domains_curr_level = tl->numa_level;
> > +#endif
> 
> A similar solution was proposed in [1] and after a few iterations, we
> arrived at [2] as a potential solution to this issue. Now that the merge
> window is behind us, Peter would it be possible to pick one of these up?
> 
> P.S. Leon has confirmed this solved the splat of their deployments too
> on an earlier version [3].
> 
> [1] https://lore.kernel.org/lkml/20250624041235.1589-1-kprateek.nayak@xxxxxxx/
> [2] https://lore.kernel.org/lkml/20250715040824.893-1-kprateek.nayak@xxxxxxx/
> [3] https://lore.kernel.org/lkml/20250720104136.GI402218@unreal/

I'm sure that's stuck somewhere in my holiday backlog ... Let me go try
and find it.