sched debug: add name to sched_domain sysctl entries

add /proc/sys/kernel/sched_domain/cpu0/domain0/name, to make
it easier to see which specific scheduler domain remained at
that entry.

Since we process the scheduler domain tree and
simplify it, it's not always immediately clear during debugging
which domain came from where.

depends on CONFIG_SCHED_DEBUG=y.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

include/linux/sched.h

@@ -824,6 +824,9 @@ struct sched_domain {
 	unsigned int ttwu_move_affine;
 	unsigned int ttwu_move_balance;
 #endif
+#ifdef CONFIG_SCHED_DEBUG
+	char *name;
+#endif
 };
 
 extern void partition_sched_domains(int ndoms_new, cpumask_t *doms_new,