From: Eric Dumazet <edumazet@google.com>
Date: Fri, 9 Feb 2024 15:31:00 +0000 (+0000)
Subject: net: use synchronize_rcu_expedited in cleanup_net()
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=78c3253f27e579f7f3a1f5c0cb8266693a7b4f41;p=users%2Fjedix%2Flinux-maple.git

net: use synchronize_rcu_expedited in cleanup_net()

cleanup_net() is calling synchronize_rcu() right before
acquiring RTNL.

synchronize_rcu() is much slower than synchronize_rcu_expedited(),
and cleanup_net() is currently single threaded. In many workloads
we want cleanup_net() to be fast, in order to free memory and various
sysfs and procfs entries as fast as possible.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 233ec0cdd0111..f0540c5575157 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -622,7 +622,7 @@ static void cleanup_net(struct work_struct *work)
 	 * the rcu_barrier() below isn't sufficient alone.
 	 * Also the pre_exit() and exit() methods need this barrier.
 	 */
-	synchronize_rcu();
+	synchronize_rcu_expedited();
 
 	rtnl_lock();
 	list_for_each_entry_reverse(ops, &pernet_list, list) {