Currently, the per-cpu rcu_data structure's->defer_qs_iw is initialized by
IRQ_WORK_INIT_HARD(), this means the rcu_preempt_deferred_qs_handler()
always be executed in the hardirq context of irq-disabled.
This commit therefore remove local_irq_save/restore() operations in
rcu_preempt_deferred_qs_handler() and add lockdep_assert_irqs_disabled()
check, if someone mistakenly invokes this function in hardirq enabled
context will splat.
Signed-off-by: Zqiang <qiang.zh...@linux.dev>
---
kernel/rcu/tree_plugin.h | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index fc14adf15cbb..57e2ae51c0b2 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -626,11 +626,10 @@ notrace void rcu_preempt_deferred_qs(struct task_struct
*t)
*/
static void rcu_preempt_deferred_qs_handler(struct irq_work *iwp)
{
- unsigned long flags;
struct rcu_data *rdp;
+ lockdep_assert_irqs_disabled();
rdp = container_of(iwp, struct rcu_data, defer_qs_iw);
- local_irq_save(flags);
/*
* If the IRQ work handler happens to run in the middle of RCU read-side
@@ -647,8 +646,6 @@ static void rcu_preempt_deferred_qs_handler(struct irq_work
*iwp)
*/
if (rcu_preempt_depth() > 0)
WRITE_ONCE(rdp->defer_qs_iw_pending, DEFER_QS_IDLE);
-
- local_irq_restore(flags);
}
/*
--
2.48.1
