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| author | Eric Dumazet <eric.dumazet@gmail.com> | 2011-05-12 17:46:56 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-05-12 17:46:56 -0400 |
| commit | f607a158004d75c9005423ce1ba70dc6ec3dd9c2 (patch) | |
| tree | 87932db617f445111cb72f5fa0d8f4eaecc91b45 /net/802/garp.c | |
| parent | e154b639bbe53dc91d1873cd37d162bb2fe87aab (diff) | |
| download | lwn-f607a158004d75c9005423ce1ba70dc6ec3dd9c2.tar.gz lwn-f607a158004d75c9005423ce1ba70dc6ec3dd9c2.zip | |
garp: remove last synchronize_rcu() call
When removing last vlan from a device, garp_uninit_applicant() calls
synchronize_rcu() to make sure no user can still manipulate struct
garp_applicant before we free it.
Use call_rcu() instead, as a step to further net_device dismantle
optimizations.
Add the temporary garp_cleanup_module() function to make sure no pending
call_rcu() are left at module unload time [ this will be removed when
kfree_rcu() is available ]
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/802/garp.c')
| -rw-r--r-- | net/802/garp.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/net/802/garp.c b/net/802/garp.c index 5dbe8967bbd5..f8300a8b5fbc 100644 --- a/net/802/garp.c +++ b/net/802/garp.c @@ -603,6 +603,11 @@ err1: } EXPORT_SYMBOL_GPL(garp_init_applicant); +static void garp_app_kfree_rcu(struct rcu_head *head) +{ + kfree(container_of(head, struct garp_applicant, rcu)); +} + void garp_uninit_applicant(struct net_device *dev, struct garp_application *appl) { struct garp_port *port = rtnl_dereference(dev->garp_port); @@ -611,7 +616,6 @@ void garp_uninit_applicant(struct net_device *dev, struct garp_application *appl ASSERT_RTNL(); rcu_assign_pointer(port->applicants[appl->type], NULL); - synchronize_rcu(); /* Delete timer and generate a final TRANSMIT_PDU event to flush out * all pending messages before the applicant is gone. */ @@ -621,7 +625,7 @@ void garp_uninit_applicant(struct net_device *dev, struct garp_application *appl garp_queue_xmit(app); dev_mc_del(dev, appl->proto.group_address); - kfree(app); + call_rcu(&app->rcu, garp_app_kfree_rcu); garp_release_port(dev); } EXPORT_SYMBOL_GPL(garp_uninit_applicant); @@ -639,3 +643,9 @@ void garp_unregister_application(struct garp_application *appl) stp_proto_unregister(&appl->proto); } EXPORT_SYMBOL_GPL(garp_unregister_application); + +static void __exit garp_cleanup_module(void) +{ + rcu_barrier(); /* Wait for completion of call_rcu()'s */ +} +module_exit(garp_cleanup_module); |