timers/migration: Simplify top level detection on group setup

Having a single group on a given level is enough to know this is the
top level, because a root has to have at least two children, unless that
root is the only group and the children are actual CPUs.

Simplify the test in tmigr_setup_groups() accordingly.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250114231507.21672-5-frederic@kernel.org

diff --git a/kernel/time/timer_migration.c b/kernel/time/timer_migration.c
index 8d57f7686bb03a1f2e81365348f450233c8cd7a1..61633762f6bf9e9cd1d9d0b138decec2416827c7 100644 (file)
--- a/kernel/time/timer_migration.c
+++ b/kernel/time/timer_migration.c
@@ -1624,9 +1624,7 @@ static int tmigr_setup_groups(unsigned int cpu, unsigned int node)
                 * be different from tmigr_hierarchy_levels, contains only a
                 * single group.
                 */
-               if (group->parent || i == tmigr_hierarchy_levels ||
-                   (list_empty(&tmigr_level_list[i]) &&
-                    list_is_singular(&tmigr_level_list[i - 1])))
+               if (group->parent || list_is_singular(&tmigr_level_list[i - 1]))
                        break;
 
        } while (i < tmigr_hierarchy_levels);