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authorEric Dumazet <eric.dumazet@gmail.com>2011-05-12 17:46:56 -0400
committerDavid S. Miller <davem@davemloft.net>2011-05-12 17:46:56 -0400
commitf607a158004d75c9005423ce1ba70dc6ec3dd9c2 (patch)
tree87932db617f445111cb72f5fa0d8f4eaecc91b45
parente154b639bbe53dc91d1873cd37d162bb2fe87aab (diff)
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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>
-rw-r--r--include/net/garp.h1
-rw-r--r--net/802/garp.c14
2 files changed, 13 insertions, 2 deletions
diff --git a/include/net/garp.h b/include/net/garp.h
index 8cabbf087169..834d8add9e5f 100644
--- a/include/net/garp.h
+++ b/include/net/garp.h
@@ -104,6 +104,7 @@ struct garp_applicant {
struct sk_buff_head queue;
struct sk_buff *pdu;
struct rb_root gid;
+ struct rcu_head rcu;
};
struct garp_port {
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);