diff options
author | Eric Dumazet <edumazet@google.com> | 2012-08-22 13:19:46 -0400 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2012-08-23 00:50:36 -0400 |
commit | 0115e8e30d6fcdd4b8faa30d3ffd90859a591f51 (patch) | |
tree | 725026e2192e57b98366947ab53c73689ca040a8 /net/core/rtnetlink.c | |
parent | bf277b0ccea7d2422b85e232017ce3fddbe9c49c (diff) |
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/core/rtnetlink.c')
-rw-r--r-- | net/core/rtnetlink.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 34d975b0f277..c64efcff8078 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c | |||
@@ -2358,7 +2358,7 @@ static int rtnetlink_event(struct notifier_block *this, unsigned long event, voi | |||
2358 | case NETDEV_PRE_TYPE_CHANGE: | 2358 | case NETDEV_PRE_TYPE_CHANGE: |
2359 | case NETDEV_GOING_DOWN: | 2359 | case NETDEV_GOING_DOWN: |
2360 | case NETDEV_UNREGISTER: | 2360 | case NETDEV_UNREGISTER: |
2361 | case NETDEV_UNREGISTER_BATCH: | 2361 | case NETDEV_UNREGISTER_FINAL: |
2362 | case NETDEV_RELEASE: | 2362 | case NETDEV_RELEASE: |
2363 | case NETDEV_JOIN: | 2363 | case NETDEV_JOIN: |
2364 | break; | 2364 | break; |