[PATCH 6.12.y 3/7] timers/migration: Simplify top level detection on group setup

From: Ionut Nechita

Date: Fri Mar 20 2026 - 16:46:00 EST


From: Frederic Weisbecker <frederic@xxxxxxxxxx>

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@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/all/20250114231507.21672-5-frederic@xxxxxxxxxx
---
kernel/time/timer_migration.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/kernel/time/timer_migration.c b/kernel/time/timer_migration.c
index 0707f1ef05f7e..2f6330831f084 100644
--- a/kernel/time/timer_migration.c
+++ b/kernel/time/timer_migration.c
@@ -1670,9 +1670,7 @@ 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);
--
2.53.0