The following commit has been merged into the locking/core branch of tip:
Commit-ID: a5959728548caf0aa17879342ee6571a29d54574
Gitweb: https://git.kernel.org/tip/a5959728548caf0aa17879342ee6571a29d54574
Author: Aniket Gattani <aniketgattani@google.com>
AuthorDate: Sun, 03 May 2026 21:22:04
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Tue, 05 May 2026 12:50:48 +02:00
sched/membarrier: Modernize membarrier_global_expedited with cleanup guards
Replace explicit lock/unlock and free calls with scoped guards and
automatic cleanup constructs.
Signed-off-by: Aniket Gattani <aniketgattani@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260503212205.3714217-3-aniketgattani@google.com
---
kernel/sched/membarrier.c | 21 ++++-----------------
1 file changed, 4 insertions(+), 17 deletions(-)
diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c
index 3d88e90..12b68a7 100644
--- a/kernel/sched/membarrier.c
+++ b/kernel/sched/membarrier.c
@@ -267,23 +267,19 @@ void membarrier_update_current_mm(struct mm_struct *next_mm)
static int membarrier_global_expedited(void)
{
+ cpumask_var_t __free(free_cpumask_var) tmpmask = CPUMASK_VAR_NULL;
int cpu;
- cpumask_var_t tmpmask;
if (num_online_cpus() == 1)
return 0;
- /*
- * Matches memory barriers after rq->curr modification in
- * scheduler.
- */
- smp_mb(); /* system call entry is not a mb. */
-
if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL))
return -ENOMEM;
+ guard(mb)();
SERIALIZE_IPI();
- cpus_read_lock();
+ guard(cpus_read_lock)();
+
rcu_read_lock();
for_each_online_cpu(cpu) {
struct task_struct *p;
@@ -319,15 +315,6 @@ static int membarrier_global_expedited(void)
smp_call_function_many(tmpmask, ipi_mb, NULL, 1);
preempt_enable();
- free_cpumask_var(tmpmask);
- cpus_read_unlock();
-
- /*
- * Memory barrier on the caller thread _after_ we finished
- * waiting for the last IPI. Matches memory barriers before
- * rq->curr modification in scheduler.
- */
- smp_mb(); /* exit from system call is not a mb */
return 0;
}