1 files changed, 15 insertions, 1 deletions
diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h
index fe09d3268bc9..b5d9d7c2b8ad 100644
--- a/include/linux/sched/topology.h
+++ b/include/linux/sched/topology.h
@@ -67,7 +67,21 @@ struct sched_domain_shared {
 	atomic_t	ref;
 	atomic_t	nr_busy_cpus;
 	int		has_idle_cores;
-	int		nr_idle_scan;
+	union {
+		int	nr_idle_scan;
+		/*
+		 * Used during allocation to claim the sched_domain_shared
+		 * object at multiple levels.
+		 *
+		 * Note: between build and the first periodic LB tick, which
+		 * rewrites the union via update_idle_cpu_scan(), readers of
+		 * nr_idle_scan may observe the transient SD_* flag value as
+		 * the scan bound. The flag bits are small positive integers,
+		 * so the effect is just a slightly relaxed scan bound for one
+		 * window and self-heals on the first tick.
+		 */
+		int	alloc_flags;
+	};
 #ifdef CONFIG_SCHED_CACHE
 	unsigned long	util_avg;
 	unsigned long	capacity;