diff options
author | Eric Dumazet <edumazet@google.com> | 2012-08-22 17:19:46 (GMT) |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2012-08-23 04:50:36 (GMT) |
commit | 0115e8e30d6fcdd4b8faa30d3ffd90859a591f51 (patch) | |
tree | 725026e2192e57b98366947ab53c73689ca040a8 /net | |
parent | bf277b0ccea7d2422b85e232017ce3fddbe9c49c (diff) | |
download | linux-fsl-qoriq-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')
-rw-r--r-- | net/core/dev.c | 22 | ||||
-rw-r--r-- | net/core/dst.c | 2 | ||||
-rw-r--r-- | net/core/fib_rules.c | 3 | ||||
-rw-r--r-- | net/core/rtnetlink.c | 2 | ||||
-rw-r--r-- | net/ipv4/devinet.c | 6 | ||||
-rw-r--r-- | net/ipv4/fib_frontend.c | 8 | ||||
-rw-r--r-- | net/ipv6/addrconf.c | 6 |
7 files changed, 26 insertions, 23 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 088923f..0640d2a 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1406,7 +1406,6 @@ rollback: nb->notifier_call(nb, NETDEV_DOWN, dev); } nb->notifier_call(nb, NETDEV_UNREGISTER, dev); - nb->notifier_call(nb, NETDEV_UNREGISTER_BATCH, dev); } } @@ -1448,7 +1447,6 @@ int unregister_netdevice_notifier(struct notifier_block *nb) nb->notifier_call(nb, NETDEV_DOWN, dev); } nb->notifier_call(nb, NETDEV_UNREGISTER, dev); - nb->notifier_call(nb, NETDEV_UNREGISTER_BATCH, dev); } } unlock: @@ -1468,7 +1466,8 @@ EXPORT_SYMBOL(unregister_netdevice_notifier); int call_netdevice_notifiers(unsigned long val, struct net_device *dev) { - ASSERT_RTNL(); + if (val != NETDEV_UNREGISTER_FINAL) + ASSERT_RTNL(); return raw_notifier_call_chain(&netdev_chain, val, dev); } EXPORT_SYMBOL(call_netdevice_notifiers); @@ -5331,10 +5330,6 @@ static void rollback_registered_many(struct list_head *head) netdev_unregister_kobject(dev); } - /* Process any work delayed until the end of the batch */ - dev = list_first_entry(head, struct net_device, unreg_list); - call_netdevice_notifiers(NETDEV_UNREGISTER_BATCH, dev); - synchronize_net(); list_for_each_entry(dev, head, unreg_list) @@ -5787,9 +5782,8 @@ static void netdev_wait_allrefs(struct net_device *dev) /* Rebroadcast unregister notification */ call_netdevice_notifiers(NETDEV_UNREGISTER, dev); - /* don't resend NETDEV_UNREGISTER_BATCH, _BATCH users - * should have already handle it the first time */ - + rcu_barrier(); + call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev); if (test_bit(__LINK_STATE_LINKWATCH_PENDING, &dev->state)) { /* We must not have linkwatch events @@ -5851,9 +5845,8 @@ void netdev_run_todo(void) __rtnl_unlock(); - /* Wait for rcu callbacks to finish before attempting to drain - * the device list. This usually avoids a 250ms wait. - */ + + /* Wait for rcu callbacks to finish before next phase */ if (!list_empty(&list)) rcu_barrier(); @@ -5862,6 +5855,8 @@ void netdev_run_todo(void) = list_first_entry(&list, struct net_device, todo_list); list_del(&dev->todo_list); + call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev); + if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) { pr_err("network todo '%s' but state %d\n", dev->name, dev->reg_state); @@ -6256,7 +6251,6 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char the device is just moving and can keep their slaves up. */ call_netdevice_notifiers(NETDEV_UNREGISTER, dev); - call_netdevice_notifiers(NETDEV_UNREGISTER_BATCH, dev); rtmsg_ifinfo(RTM_DELLINK, dev, ~0U); /* diff --git a/net/core/dst.c b/net/core/dst.c index 56d6361..f6593d2 100644 --- a/net/core/dst.c +++ b/net/core/dst.c @@ -374,7 +374,7 @@ static int dst_dev_event(struct notifier_block *this, unsigned long event, struct dst_entry *dst, *last = NULL; switch (event) { - case NETDEV_UNREGISTER: + case NETDEV_UNREGISTER_FINAL: case NETDEV_DOWN: mutex_lock(&dst_gc_mutex); for (dst = dst_busy_list; dst; dst = dst->next) { diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c index ab7db83..5850937 100644 --- a/net/core/fib_rules.c +++ b/net/core/fib_rules.c @@ -711,15 +711,16 @@ static int fib_rules_event(struct notifier_block *this, unsigned long event, struct net *net = dev_net(dev); struct fib_rules_ops *ops; - ASSERT_RTNL(); switch (event) { case NETDEV_REGISTER: + ASSERT_RTNL(); list_for_each_entry(ops, &net->rules_ops, list) attach_rules(&ops->rules_list, dev); break; case NETDEV_UNREGISTER: + ASSERT_RTNL(); list_for_each_entry(ops, &net->rules_ops, list) detach_rules(&ops->rules_list, dev); break; diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 34d975b..c64efcf 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 case NETDEV_PRE_TYPE_CHANGE: case NETDEV_GOING_DOWN: case NETDEV_UNREGISTER: - case NETDEV_UNREGISTER_BATCH: + case NETDEV_UNREGISTER_FINAL: case NETDEV_RELEASE: case NETDEV_JOIN: break; diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index adf273f..6a5e6e4 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -1147,8 +1147,12 @@ static int inetdev_event(struct notifier_block *this, unsigned long event, void *ptr) { struct net_device *dev = ptr; - struct in_device *in_dev = __in_dev_get_rtnl(dev); + struct in_device *in_dev; + if (event == NETDEV_UNREGISTER_FINAL) + goto out; + + in_dev = __in_dev_get_rtnl(dev); ASSERT_RTNL(); if (!in_dev) { diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c index 7f073a3..fd7d9ae 100644 --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -1041,7 +1041,7 @@ static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) { struct net_device *dev = ptr; - struct in_device *in_dev = __in_dev_get_rtnl(dev); + struct in_device *in_dev; struct net *net = dev_net(dev); if (event == NETDEV_UNREGISTER) { @@ -1050,9 +1050,11 @@ static int fib_netdev_event(struct notifier_block *this, unsigned long event, vo return NOTIFY_DONE; } - if (!in_dev) + if (event == NETDEV_UNREGISTER_FINAL) return NOTIFY_DONE; + in_dev = __in_dev_get_rtnl(dev); + switch (event) { case NETDEV_UP: for_ifa(in_dev) { @@ -1071,8 +1073,6 @@ static int fib_netdev_event(struct notifier_block *this, unsigned long event, vo case NETDEV_CHANGE: rt_cache_flush(dev_net(dev), 0); break; - case NETDEV_UNREGISTER_BATCH: - break; } return NOTIFY_DONE; } diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 6bc85f7..e581009 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) { |