The following commit has been merged into the sched/core branch of tip:

Commit-ID:     d943b86dfbf4e9b76be30cf90b1b3f82ff9abbac
Gitweb:        https://git.kernel.org/tip/d943b86dfbf4e9b76be30cf90b1b3f82ff9abbac
Author:        Chen Yu <yu.c.chen@intel.com>
AuthorDate:    Wed, 13 May 2026 13:39:18 -07:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Mon, 18 May 2026 21:33:16 +02:00

sched/cache: Fix rcu warning when accessing sd_llc domain

rcu_dereference_all() should be used to access the
sd_llc domain under RCU protection.

This bug was reported by sashiko.

Fixes: df0d98475954 ("sched/cache: Introduce infrastructure for cache-aware load balancing")
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Co-developed-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/2dc49455e861215d8059a1c877953f0b95990038.1778703694.git.tim.c.chen@linux.intel.com
---
 kernel/sched/fair.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 76ac6a8..c549ad4 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1814,7 +1814,7 @@ static void task_cache_work(struct callback_head *work)
 
 		for_each_cpu(cpu, cpus) {
 			/* XXX sched_cluster_active */
-			struct sched_domain *sd = per_cpu(sd_llc, cpu);
+			struct sched_domain *sd = rcu_dereference_all(per_cpu(sd_llc, cpu));
 			unsigned long occ, m_occ = 0, a_occ = 0;
 			int m_cpu = -1, i;