Merge tag 'sched-urgent-2026-09-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Ingo Molnar:

 - Fix LLC mis-scheduling bugs (Tim Chen, Lu Wang)

 - Fix cache-grouping related scheduling statistics UAF bugs (Tim Chen)

 - Skip kernel threads for cache aware scheduling to rubustify the code
   (Chen Yu)

 - Refresh LLC capacity across CPU hotplug, to fix capacity
   underestimation bug (Davi Chaves Azevedo)

 - Account PSI IRQ time to the execution context, not the scheduling
   context, to fix proxy scheduling accounting bug (Zhan Xusheng)

* tag 'sched-urgent-2026-09-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/core: Account PSI IRQ time to the execution context, not the scheduling context
  sched/cache: Refresh LLC capacity across CPU hotplug, to fix capacity underestimation bug
  sched/cache: Skip kernel threads for cache aware scheduling to rubustify the code
  sched/cache: Introduce task_struct->sched_cache_grp to fix UAF
  sched/cache: Decouple sched_cache_group from mm to fix UAF
  sched/cache: Honor migrate_llc_task semantics in active load balance, to fix LLC mis-scheduling bug
  sched/cache: Keep nr_pref_llc_running in the runnable domain, to fix LLC mis-scheduling bug

1 files changed, 6 insertions, 5 deletions

diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
index 9f9c72727a05..7a47a392568a 100644
--- a/drivers/base/cacheinfo.c
+++ b/drivers/base/cacheinfo.c
@@ -1040,9 +1040,10 @@ static int cacheinfo_cpu_online(unsigned int cpu)
 	rc = cache_add_dev(cpu);
 	if (rc)
 		goto err;
-	if (cpu_map_shared_cache(true, cpu, &cpu_map))
+	if (cpu_map_shared_cache(true, cpu, &cpu_map)) {
 		update_per_cpu_data_slice_size(true, cpu, cpu_map);
-	sched_update_llc_bytes(cpu);
+		sched_update_llc_bytes(cpu_map);
+	}
 	return 0;
 err:
 	free_cache_attributes(cpu);
@@ -1059,10 +1060,10 @@ static int cacheinfo_cpu_pre_down(unsigned int cpu)
 		cpu_cache_sysfs_exit(cpu);
 
 	free_cache_attributes(cpu);
-	if (nr_shared > 1)
+	if (nr_shared > 1) {
 		update_per_cpu_data_slice_size(false, cpu, cpu_map);
-
-	sched_update_llc_bytes(cpu);
+		sched_update_llc_bytes(cpu_map);
+	}
 
 	return 0;
 }