net: get rid of rtable->idev
It seems idev field in struct rtable has no special purpose, but adding
extra atomic ops.
We hold refcounts on the device itself (using percpu data, so pretty
cheap in current kernel).
infiniband case is solved using dst.dev instead of idev->dev
Removal of this field means routing without route cache is now using
shared data, percpu data, and only potential contention is a pair of
atomic ops on struct neighbour per forwarded packet.
About 5% speedup on routing test.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Roland Dreier <rolandd@cisco.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 987bf9a..5955965 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -140,13 +140,15 @@
static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
static void ipv4_dst_destroy(struct dst_entry *dst);
-static void ipv4_dst_ifdown(struct dst_entry *dst,
- struct net_device *dev, int how);
static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
static void ipv4_link_failure(struct sk_buff *skb);
static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
static int rt_garbage_collect(struct dst_ops *ops);
+static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
+ int how)
+{
+}
static struct dst_ops ipv4_dst_ops = {
.family = AF_INET,
@@ -1433,8 +1435,6 @@
rt->dst.child = NULL;
if (rt->dst.dev)
dev_hold(rt->dst.dev);
- if (rt->idev)
- in_dev_hold(rt->idev);
rt->dst.obsolete = -1;
rt->dst.lastuse = jiffies;
rt->dst.path = &rt->dst;
@@ -1728,33 +1728,13 @@
{
struct rtable *rt = (struct rtable *) dst;
struct inet_peer *peer = rt->peer;
- struct in_device *idev = rt->idev;
if (peer) {
rt->peer = NULL;
inet_putpeer(peer);
}
-
- if (idev) {
- rt->idev = NULL;
- in_dev_put(idev);
- }
}
-static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
- int how)
-{
- struct rtable *rt = (struct rtable *) dst;
- struct in_device *idev = rt->idev;
- if (dev != dev_net(dev)->loopback_dev && idev && idev->dev == dev) {
- struct in_device *loopback_idev =
- in_dev_get(dev_net(dev)->loopback_dev);
- if (loopback_idev) {
- rt->idev = loopback_idev;
- in_dev_put(idev);
- }
- }
-}
static void ipv4_link_failure(struct sk_buff *skb)
{
@@ -1910,7 +1890,6 @@
rth->fl.iif = dev->ifindex;
rth->dst.dev = init_net.loopback_dev;
dev_hold(rth->dst.dev);
- rth->idev = in_dev_get(rth->dst.dev);
rth->fl.oif = 0;
rth->rt_gateway = daddr;
rth->rt_spec_dst= spec_dst;
@@ -2050,7 +2029,6 @@
rth->fl.iif = in_dev->dev->ifindex;
rth->dst.dev = (out_dev)->dev;
dev_hold(rth->dst.dev);
- rth->idev = in_dev_get(rth->dst.dev);
rth->fl.oif = 0;
rth->rt_spec_dst= spec_dst;
@@ -2231,7 +2209,6 @@
rth->fl.iif = dev->ifindex;
rth->dst.dev = net->loopback_dev;
dev_hold(rth->dst.dev);
- rth->idev = in_dev_get(rth->dst.dev);
rth->rt_gateway = daddr;
rth->rt_spec_dst= spec_dst;
rth->dst.input= ip_local_deliver;
@@ -2417,9 +2394,6 @@
if (!rth)
return -ENOBUFS;
- in_dev_hold(in_dev);
- rth->idev = in_dev;
-
atomic_set(&rth->dst.__refcnt, 1);
rth->dst.flags= DST_HOST;
if (IN_DEV_CONF_GET(in_dev, NOXFRM))
@@ -2759,9 +2733,6 @@
rt->fl = ort->fl;
- rt->idev = ort->idev;
- if (rt->idev)
- in_dev_hold(rt->idev);
rt->rt_genid = rt_genid(net);
rt->rt_flags = ort->rt_flags;
rt->rt_type = ort->rt_type;