On Wed, 2016-10-05 at 16:23 +0200, Thomas Gleixner wrote:

On Sat, 1 Oct 2016, Srinivas Pandruvada wrote:

quoted

+void sched_set_itmt_support(bool itmt_supported)
+{
+	mutex_lock(&itmt_update_mutex);
+
+	if (itmt_supported != sched_itmt_capable)
+		sched_itmt_capable = itmt_supported;

Yikes. What is this conditional for? The only value it has is to confuse
the reader.

Will remove the check.

quoted

+
+	mutex_unlock(&itmt_update_mutex);
+}
+
+DEFINE_PER_CPU_READ_MOSTLY(int, sched_core_priority);

Darn. Do not stick variable definitiions in the middle of the code and
especially not glued to the function w/o a newline in between. Move it to
the top of the file.

Will move to top of file.

quoted

+int arch_asym_cpu_priority(int cpu)
+{
+	return per_cpu(sched_core_priority, cpu);
+}

quoted

+void sched_set_itmt_core_prio(int prio, int core_cpu)
+{
+	int cpu, i = 1;
+
+	for_each_cpu(cpu, topology_sibling_cpumask(core_cpu)) {
+		int smt_prio;
+
+		/*
+		 * Ensure that the siblings are moved to the end
+		 * of the priority chain and only used when
+		 * all other high priority cpus are out of capacity.
+		 */
+		smt_prio = prio * smp_num_siblings / i;
+		i++;

Your code ordering is really random. What has this i++ to do with the
store? Nothing. It just makes reading the code harder. Just move it below
the store.

Will move it to the end of for loop.

quoted

+		per_cpu(sched_core_priority, cpu) = smt_prio;

Thanks.

Tim