macvlan: remove one synchronize_rcu() call

When one macvlan device is dismantled, we can avoid one
synchronize_rcu() call done after deletion from hash list, since caller
will perform a synchronize_net() call after its ndo_stop() call.

Add a new netdev->dismantle field to signal this dismantle intent.

Reduces RTNL hold time.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Patrick McHardy <kaber@trash.net>
CC: Ben Greear <greearb@candelatech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 1 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 155de2094e71..d94537914a71 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5126,7 +5126,7 @@ static void rollback_registered_many(struct list_head *head)
                         list_del(&dev->unreg_list);
                         continue;
                 }
-
+                dev->dismantle = true;
                 BUG_ON(dev->reg_state != NETREG_REGISTERED);
         }