On 4/21/26 4:57 AM, Thomas Gleixner wrote:
On Mon, Apr 20 2026 at 23:03, Waiman Long wrote:
As HK_TYPE_TIMER cpumask is going to be changeable at run time, use
RCU to protect access to the cpumask.
Signed-off-by: Waiman Long <[email protected]>
---
kernel/cpu.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/kernel/cpu.c b/kernel/cpu.c
index bc4f7a9ba64e..0d02b5d7a7ba 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -1890,6 +1890,8 @@ int freeze_secondary_cpus(int primary)
cpu_maps_update_begin();
if (primary == -1) {
primary = cpumask_first(cpu_online_mask);
+
+ guard(rcu)();
if (!housekeeping_cpu(primary, HK_TYPE_TIMER))
primary = housekeeping_any_cpu(HK_TYPE_TIMER);
housekeeping_cpu() and housekeeping_any_cpu() can operate on two
different CPU masks once the runtime update is enabled.
Seriously?
Good point, will fix that in the next version.
Cheers,
Longman
