From 9eb43e765368f835d92c93844ebce30da7efeb84 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 3 Aug 2012 21:27:25 +0000 Subject: [PATCH] ipv4: Introduce IN_DEV_NET_ROUTE_LOCALNET performance profiles show a high cost in the IN_DEV_ROUTE_LOCALNET() call done in ip_route_input_slow(), because of multiple dereferences, even if cache lines are clean and available in cpu caches. Since we already have the 'net' pointer, introduce IN_DEV_NET_ROUTE_LOCALNET() macro avoiding two dereferences (dev_net(in_dev->dev)) Also change the tests to use IN_DEV_NET_ROUTE_LOCALNET() only if saddr or/and daddr are loopback addresse. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/linux/inetdevice.h | 11 +++++++++-- net/ipv4/route.c | 11 +++++++---- 2 files changed, 16 insertions(+), 6 deletions(-) diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h index 67f9ddacb70..d032780d0ce 100644 --- a/include/linux/inetdevice.h +++ b/include/linux/inetdevice.h @@ -104,9 +104,14 @@ static inline void ipv4_devconf_setall(struct in_device *in_dev) #define IN_DEV_ANDCONF(in_dev, attr) \ (IPV4_DEVCONF_ALL(dev_net(in_dev->dev), attr) && \ IN_DEV_CONF_GET((in_dev), attr)) -#define IN_DEV_ORCONF(in_dev, attr) \ - (IPV4_DEVCONF_ALL(dev_net(in_dev->dev), attr) || \ + +#define IN_DEV_NET_ORCONF(in_dev, net, attr) \ + (IPV4_DEVCONF_ALL(net, attr) || \ IN_DEV_CONF_GET((in_dev), attr)) + +#define IN_DEV_ORCONF(in_dev, attr) \ + IN_DEV_NET_ORCONF(in_dev, dev_net(in_dev->dev), attr) + #define IN_DEV_MAXCONF(in_dev, attr) \ (max(IPV4_DEVCONF_ALL(dev_net(in_dev->dev), attr), \ IN_DEV_CONF_GET((in_dev), attr))) @@ -133,6 +138,8 @@ static inline void ipv4_devconf_setall(struct in_device *in_dev) IN_DEV_ORCONF((in_dev), \ PROMOTE_SECONDARIES) #define IN_DEV_ROUTE_LOCALNET(in_dev) IN_DEV_ORCONF(in_dev, ROUTE_LOCALNET) +#define IN_DEV_NET_ROUTE_LOCALNET(in_dev, net) \ + IN_DEV_NET_ORCONF(in_dev, net, ROUTE_LOCALNET) #define IN_DEV_RX_REDIRECTS(in_dev) \ ((IN_DEV_FORWARD(in_dev) && \ diff --git a/net/ipv4/route.c b/net/ipv4/route.c index e4ba974f143..21ad369014c 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1587,11 +1587,14 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, if (ipv4_is_zeronet(daddr)) goto martian_destination; - if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) { - if (ipv4_is_loopback(daddr)) + /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), + * and call it once if daddr or/and saddr are loopback addresses + */ + if (ipv4_is_loopback(daddr)) { + if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) goto martian_destination; - - if (ipv4_is_loopback(saddr)) + } else if (ipv4_is_loopback(saddr)) { + if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) goto martian_source; } -- 2.20.1