[PATCH] fs: annotate cdev_lock with __cacheline_aligned_in_smp

From: Mateusz Guzik

Date: Wed Dec 03 2025 - 04:55:14 EST


No need for the crapper to be susceptible to false-sharing.

Signed-off-by: Mateusz Guzik <mjguzik@xxxxxxxxx>
---
fs/char_dev.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/char_dev.c b/fs/char_dev.c
index c2ddb998f3c9..84a5a0699373 100644
--- a/fs/char_dev.c
+++ b/fs/char_dev.c
@@ -343,7 +343,7 @@ void __unregister_chrdev(unsigned int major, unsigned int baseminor,
kfree(cd);
}

-static DEFINE_SPINLOCK(cdev_lock);
+static __cacheline_aligned_in_smp DEFINE_SPINLOCK(cdev_lock);

static struct kobject *cdev_get(struct cdev *p)
{
--
2.48.1