From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sun, 31 Dec 2023 18:16:26 +0100

Move one assignment for the variable “cb_mutex” closer to the place
where this pointer is used.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 net/netlink/af_netlink.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index cfddc9c6a376..12a0b6f8be19 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -2019,7 +2019,7 @@ __netlink_kernel_create(struct net *net, int unit, struct module *module,
 	struct sock *sk;
 	struct netlink_sock *nlk;
 	struct listeners *listeners;
-	struct mutex *cb_mutex = cfg ? cfg->cb_mutex : NULL;
+	struct mutex *cb_mutex; /* Serialize data processing with callbacks */
 	unsigned int groups;

 	BUG_ON(!nl_table);
@@ -2030,6 +2030,7 @@ __netlink_kernel_create(struct net *net, int unit, struct module *module,
 	if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
 		return NULL;

+	cb_mutex = (cfg ? cfg->cb_mutex : NULL);
 	if (__netlink_create(net, sock, cb_mutex, unit, 1) < 0)
 		goto out_sock_release_nosk;

--
2.43.0

On Sun, 31 Dec 2023 18:48:11 +0100
Markus Elfring <Markus.Elfring@web.de> wrote:

> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Sun, 31 Dec 2023 18:16:26 +0100
> 
> Move one assignment for the variable “cb_mutex” closer to the place
> where this pointer is used.
> 
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>

NAK
Useless code churn, no improvement in performance or readablilty.
Compiler optimizer will do this already if it wants.