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| author | Eric Dumazet <edumazet@google.com> | 2012-08-22 21:19:46 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-08-23 08:50:36 +0400 |
| commit | 0115e8e30d6fcdd4b8faa30d3ffd90859a591f51 (patch) | |
| tree | 725026e2192e57b98366947ab53c73689ca040a8 /net/ipv6/addrconf.c | |
| parent | bf277b0ccea7d2422b85e232017ce3fddbe9c49c (diff) | |
| download | linux-0115e8e30d6fcdd4b8faa30d3ffd90859a591f51.tar.xz | |
net: remove delay at device dismantle
I noticed extra one second delay in device dismantle, tracked down to
a call to dst_dev_event() while some call_rcu() are still in RCU queues.
These call_rcu() were posted by rt_free(struct rtable *rt) calls.
We then wait a little (but one second) in netdev_wait_allrefs() before
kicking again NETDEV_UNREGISTER.
As the call_rcu() are now completed, dst_dev_event() can do the needed
device swap on busy dst.
To solve this problem, add a new NETDEV_UNREGISTER_FINAL, called
after a rcu_barrier(), but outside of RTNL lock.
Use NETDEV_UNREGISTER_FINAL with care !
Change dst_dev_event() handler to react to NETDEV_UNREGISTER_FINAL
Also remove NETDEV_UNREGISTER_BATCH, as its not used anymore after
IP cache removal.
With help from Gao feng
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Mahesh Bandewar <maheshb@google.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6/addrconf.c')
| -rw-r--r-- | net/ipv6/addrconf.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 6bc85f7c31e3..e581009cb09e 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -2566,10 +2566,14 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event, void *data) { struct net_device *dev = (struct net_device *) data; - struct inet6_dev *idev = __in6_dev_get(dev); + struct inet6_dev *idev; int run_pending = 0; int err; + if (event == NETDEV_UNREGISTER_FINAL) + return NOTIFY_DONE; + + idev = __in6_dev_get(dev); switch (event) { case NETDEV_REGISTER: if (!idev && dev->mtu >= IPV6_MIN_MTU) { |