[PATCH] rcu/srcutiny: don't return before reenabling preemption

From: Michal Schmidt
Date: Mon Oct 07 2024 - 06:14:47 EST


Code after the return statement is dead. Enable preemption before
returning from srcu_drive_gp().

This will be important when/if PREEMPT_AUTO (lazy resched) gets merged.

Fixes: 65b4a59557f6 ("srcu: Make Tiny SRCU explicitly disable preemption")
Signed-off-by: Michal Schmidt <mschmidt@xxxxxxxxxx>
---
kernel/rcu/srcutiny.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/rcu/srcutiny.c b/kernel/rcu/srcutiny.c
index 549c03336ee9..4dcbf8aa80ff 100644
--- a/kernel/rcu/srcutiny.c
+++ b/kernel/rcu/srcutiny.c
@@ -122,8 +122,8 @@ void srcu_drive_gp(struct work_struct *wp)
ssp = container_of(wp, struct srcu_struct, srcu_work);
preempt_disable(); // Needed for PREEMPT_AUTO
if (ssp->srcu_gp_running || ULONG_CMP_GE(ssp->srcu_idx, READ_ONCE(ssp->srcu_idx_max))) {
- return; /* Already running or nothing to do. */
preempt_enable();
+ return; /* Already running or nothing to do. */
}

/* Remove recently arrived callbacks and wait for readers. */
--
2.46.2