Subject: Re: [PATCH v5 1/6] powerpc/pseries: rename min_common_depth to primary_domain_index

From: David Gibson <[email-masked]>
Date: Thu, 22 Jul 2021 12:36:46 +1000

On Thu, Jul 22, 2021 at 11:59:15AM +1000, David Gibson wrote:
> On Mon, Jun 28, 2021 at 08:41:12PM +0530, Aneesh Kumar K.V wrote:
> > No functional change in this patch.
> 
> The new name does not match how you describe "primary domain index" in
> the documentation from patch 6/6.  There it comes from the values in
> associativity-reference-points, but here it simply comes from the
> lengths of all the associativity properties.

No, sorry, I misread this code... misled by the old name, so it's a
good thing you're changing it.

But.. I'm still not sure the new name is accurate, either...

[snip]
> >  	if (form1_affinity) {
> > -		depth = of_read_number(distance_ref_points, 1);
> > +		index = of_read_number(distance_ref_points, 1);

AFACIT distance_ref_points hasn't been altered from the
of_get_property() at this point, so isn't this setting depth / index
to the number of entries in ref-points, rather than the value of the
first entry (which is what primary domain index is supposed to be).

> >  	} else {
> >  		if (distance_ref_points_depth < 2) {
> >  			printk(KERN_WARNING "NUMA: "
> > @@ -334,7 +334,7 @@ static int __init find_min_common_depth(void)
> >  			goto err;
> >  		}
> >  
> > -		depth = of_read_number(&distance_ref_points[1], 1);
> > +		index = of_read_number(&distance_ref_points[1], 1);
> >  	}
> >  
> >  	/*
> > @@ -348,7 +348,7 @@ static int __init find_min_common_depth(void)
> >  	}
> >  
> >  	of_node_put(root);
> > -	return depth;
> > +	return index;
> >  
> >  err:
> >  	of_node_put(root);
> > @@ -437,16 +437,16 @@ int of_drconf_to_nid_single(struct drmem_lmb *lmb)
> >  	int nid = default_nid;
> >  	int rc, index;
> >  
> > -	if ((min_common_depth < 0) || !numa_enabled)
> > +	if ((primary_domain_index < 0) || !numa_enabled)
> >  		return default_nid;
> >  
> >  	rc = of_get_assoc_arrays(&aa);
> >  	if (rc)
> >  		return default_nid;
> >  
> > -	if (min_common_depth <= aa.array_sz &&
> > +	if (primary_domain_index <= aa.array_sz &&
> >  	    !(lmb->flags & DRCONF_MEM_AI_INVALID) && lmb->aa_index < aa.n_arrays) {
> > -		index = lmb->aa_index * aa.array_sz + min_common_depth - 1;
> > +		index = lmb->aa_index * aa.array_sz + primary_domain_index - 1;
> >  		nid = of_read_number(&aa.arrays[index], 1);
> >  
> >  		if (nid == 0xffff || nid >= nr_node_ids)
> > @@ -708,18 +708,18 @@ static int __init parse_numa_properties(void)
> >  		return -1;
> >  	}
> >  
> > -	min_common_depth = find_min_common_depth();
> > +	primary_domain_index = find_primary_domain_index();
> >  
> > -	if (min_common_depth < 0) {
> > +	if (primary_domain_index < 0) {
> >  		/*
> > -		 * if we fail to parse min_common_depth from device tree
> > +		 * if we fail to parse primary_domain_index from device tree
> >  		 * mark the numa disabled, boot with numa disabled.
> >  		 */
> >  		numa_enabled = false;
> > -		return min_common_depth;
> > +		return primary_domain_index;
> >  	}
> >  
> > -	dbg("NUMA associativity depth for CPU/Memory: %d\n", min_common_depth);
> > +	dbg("NUMA associativity depth for CPU/Memory: %d\n", primary_domain_index);
> >  
> >  	/*
> >  	 * Even though we connect cpus to numa domains later in SMP
> > @@ -919,14 +919,14 @@ static void __init find_possible_nodes(void)
> >  			goto out;
> >  	}
> >  
> > -	max_nodes = of_read_number(&domains[min_common_depth], 1);
> > +	max_nodes = of_read_number(&domains[primary_domain_index], 1);
> >  	for (i = 0; i < max_nodes; i++) {
> >  		if (!node_possible(i))
> >  			node_set(i, node_possible_map);
> >  	}
> >  
> >  	prop_length /= sizeof(int);
> > -	if (prop_length > min_common_depth + 2)
> > +	if (prop_length > primary_domain_index + 2)
> >  		coregroup_enabled = 1;
> >  
> >  out:
> > @@ -1259,7 +1259,7 @@ int cpu_to_coregroup_id(int cpu)
> >  		goto out;
> >  
> >  	index = of_read_number(associativity, 1);
> > -	if (index > min_common_depth + 1)
> > +	if (index > primary_domain_index + 1)
> >  		return of_read_number(&associativity[index - 1], 1);
> >  
> >  out:
> 

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson