[PATCH 1/4] locking/qspinlock: Fix 'wait_early' set but not used warning

From: Waiman Long
Date: Mon Feb 12 2024 - 22:17:37 EST


When CONFIG_LOCK_EVENT_COUNTS is off, the wait_early variable will be
set but not used. This is expected. Recent compilers will not generate
wait_early code in this case.

Add the __maybe_unused attribute to wait_early for suppressing this
W=1 warning.

Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-kbuild-all/202312260422.f4pK3f9m-lkp@xxxxxxxxx/
Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
---
kernel/locking/qspinlock_paravirt.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h
index 6a0184e9c234..ae2b12f68b90 100644
--- a/kernel/locking/qspinlock_paravirt.h
+++ b/kernel/locking/qspinlock_paravirt.h
@@ -294,8 +294,8 @@ static void pv_wait_node(struct mcs_spinlock *node, struct mcs_spinlock *prev)
{
struct pv_node *pn = (struct pv_node *)node;
struct pv_node *pp = (struct pv_node *)prev;
+ bool __maybe_unused wait_early;
int loop;
- bool wait_early;

for (;;) {
for (wait_early = false, loop = SPIN_THRESHOLD; loop; loop--) {
--
2.39.3