Re: [PATCH net-next 1/1] net: neighbour: Simplify ifdefs aroundneigh_app_ns()

From: Joe Perches
Date: Wed Aug 28 2013 - 21:26:28 EST


On Wed, 2013-08-28 at 13:09 -0600, Tim Gardner wrote:
> On 08/28/2013 12:51 PM, Joe Perches wrote:
> > On Wed, 2013-08-28 at 12:24 -0600, Tim Gardner wrote:
> >> Drop a couple of ifdef/endif pairs by moving the ifdef
> >> surrounding neigh_app_ns() to the interior of neigh_app_ns().
> > []
> >> This is an admittedly trivial change. I stumbled on it while trying to figure
> >> out why Ubuntu doesn't have CONFIG_ARPD enabled.

> > I'd be more inclined to make neigh_app_ns static inline
> > in the .h file and remove the EXPORT_SYMBOL

> I thought about that as well, but then you'd have to extern
> __neigh_notify(), which is currently a static function and large enough
> to not really be suitable for inlining. Seems like unnecessary churn to me.

Hi Tim.

As is, this makes the call to neight_app_ns
impossible to optimize away.

Perhaps this:

(this does add a possibly unused neigh_notify as a global symbol)

Rename __neigh_notify to neigh_notify and make public
Add static inline neigh_app_ns
Remove #ifdefs around use of neigh_app_ns

---

Compile tested only

include/net/neighbour.h | 10 +++++++++-
net/core/neighbour.c | 15 +++------------
net/ipv4/arp.c | 2 --
net/ipv6/ndisc.c | 2 --
4 files changed, 12 insertions(+), 17 deletions(-)

diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index 536501a..a08b0a7 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -249,7 +249,15 @@ static inline struct net *pneigh_net(const struct pneigh_entry *pneigh)
return read_pnet(&pneigh->net);
}

-void neigh_app_ns(struct neighbour *n);
+void neigh_notify(struct neighbour *n, int type, int flags);
+
+static inline void neigh_app_ns(struct neighbour *n)
+{
+#ifdef CONFIG_ARPD
+ neigh_notify(n, RTM_GETNEIGH, NLM_F_REQUEST);
+#endif
+}
+
void neigh_for_each(struct neigh_table *tbl,
void (*cb)(struct neighbour *, void *), void *cookie);
void __neigh_for_each_release(struct neigh_table *tbl,
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 60533db..6ec5f86 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -50,7 +50,6 @@ do { \
#define PNEIGH_HASHMASK 0xF

static void neigh_timer_handler(unsigned long arg);
-static void __neigh_notify(struct neighbour *n, int type, int flags);
static void neigh_update_notify(struct neighbour *neigh);
static int pneigh_ifdown(struct neigh_table *tbl, struct net_device *dev);

@@ -103,7 +102,7 @@ static void neigh_cleanup_and_release(struct neighbour *neigh)
if (neigh->parms->neigh_cleanup)
neigh->parms->neigh_cleanup(neigh);

- __neigh_notify(neigh, RTM_DELNEIGH, 0);
+ neigh_notify(neigh, RTM_DELNEIGH, 0);
neigh_release(neigh);
}

@@ -2215,7 +2214,7 @@ nla_put_failure:
static void neigh_update_notify(struct neighbour *neigh)
{
call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, neigh);
- __neigh_notify(neigh, RTM_NEWNEIGH, 0);
+ neigh_notify(neigh, RTM_NEWNEIGH, 0);
}

static int neigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb,
@@ -2735,7 +2734,7 @@ static inline size_t neigh_nlmsg_size(void)
+ nla_total_size(4); /* NDA_PROBES */
}

-static void __neigh_notify(struct neighbour *n, int type, int flags)
+void neigh_notify(struct neighbour *n, int type, int flags)
{
struct net *net = dev_net(n->dev);
struct sk_buff *skb;
@@ -2759,14 +2758,6 @@ errout:
rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
}

-#ifdef CONFIG_ARPD
-void neigh_app_ns(struct neighbour *n)
-{
- __neigh_notify(n, RTM_GETNEIGH, NLM_F_REQUEST);
-}
-EXPORT_SYMBOL(neigh_app_ns);
-#endif /* CONFIG_ARPD */
-
#ifdef CONFIG_SYSCTL
static int zero;
static int int_max = INT_MAX;
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index 4429b01..7808093 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -368,9 +368,7 @@ static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb)
} else {
probes -= neigh->parms->app_probes;
if (probes < 0) {
-#ifdef CONFIG_ARPD
neigh_app_ns(neigh);
-#endif
return;
}
}
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 04d31c2..d5693ad 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -663,9 +663,7 @@ static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
}
ndisc_send_ns(dev, neigh, target, target, saddr);
} else if ((probes -= neigh->parms->app_probes) < 0) {
-#ifdef CONFIG_ARPD
neigh_app_ns(neigh);
-#endif
} else {
addrconf_addr_solict_mult(target, &mcaddr);
ndisc_send_ns(dev, NULL, target, &mcaddr, saddr);


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