Re: [PATCH v6 2/2] powerpc: Use cpu_smallcore_sibling_mask at SMT level on bigcores

On Thu, Aug 09, 2018 at 06:26:57AM -0700, Srikar Dronamraju wrote:

* Gautham R. Shenoy [off-list ref] [2018-08-09 11:02:08]:

quoted

3) ppc64_cpu --smt=2
   SMT domain ceases to exist as each domain consists of just one
   group.

When seen in isolation, the above looks as if ppc64_cpu --smt=2 o/p says
" SMT domain ceases to exist...."

Ok. The intent was to say that one of the sched-domain level
collapses, thereby leaving only CACHE, DIE and NUMA. Will word it
better.

quoted

@@ -999,7 +1012,17 @@ static void add_cpu_to_masks(int cpu)
 {
 	int first_thread = cpu_first_thread_sibling(cpu);
 	int chipid = cpu_to_chip_id(cpu);
-	int i;
+
+	struct thread_groups tg;
+	int i, cpu_group_start = -1;
+
+	if (has_big_cores) {
+		struct device_node *dn = of_get_cpu_node(cpu, NULL);
+

Not checking for validity of dn and no of_node_puts?

Will fix this. Thanks for catching this.

quoted

+		parse_thread_groups(dn, &tg);
+		cpu_group_start = get_cpu_thread_group_start(cpu, &tg);
+		cpumask_set_cpu(cpu, cpu_smallcore_sibling_mask(cpu));
+	}

 	/*
 	 * This CPU will not be in the online mask yet so we need to manually

The rest looks good

Thanks for the review.