[PATCH] [NET] reduce sizeof(struct flow)

[Eric Dumazet]

Hi David

Each route entry includes a 'struct flow'. This structure has a current size 
of 80 bytes. This patch makes a size reduction depending on 
CONFIG_IPV6/CONFIG_IPV6_MODULE/CONFIG_DECNET/CONFIG_IP_ROUTE_FWMARK

For a platform doing IPV4 only, the new size is 36 bytes (instead of 80)
As many routers are base on PIII (L1_CACHE_SIZE=32), this saves one cache line 
per rtable entry.

Thank you

Signed-off-by: Eric Dumazet <[EMAIL PROTECTED]>


--- linux-2.6.19-rc2/include/net/flow.h 2006-10-18 06:03:08.000000000 +0200
+++ linux-2.6.19-rc2-ed/include/net/flow.h      2006-10-18 06:56:37.000000000 
+0200
@@ -18,17 +18,21 @@
                struct {
                        __be32                  daddr;
                        __be32                  saddr;
+#if defined(CONFIG_IP_ROUTE_FWMARK)
                        __u32                   fwmark;
+#endif
                        __u8                    tos;
                        __u8                    scope;
                } ip4_u;
                
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
                struct {
                        struct in6_addr         daddr;
                        struct in6_addr         saddr;
                        __u32                   fwmark;
                        __u32                   flowlabel;
                } ip6_u;
+#endif
 
                struct {
                        __le16                  daddr;
@@ -65,6 +69,7 @@
                        __u8    code;
                } icmpt;
 
+#if defined(CONFIG_DECNET)
                struct {
                        __le16  sport;
                        __le16  dport;
@@ -72,6 +77,7 @@
                        __u8    objnamel; /* Not 16 bits since max val is 16 */
                        __u8    objname[16]; /* Not zero terminated */
                } dnports;
+#endif
 
                __be32          spi;
 
--- linux-2.6.19-rc2/include/net/xfrm.h 2006-10-18 06:21:19.000000000 +0200
+++ linux-2.6.19-rc2-ed/include/net/xfrm.h      2006-10-18 06:53:41.000000000 
+0200
@@ -517,6 +517,7 @@
                (fl->oif == sel->ifindex || !sel->ifindex);
 }
 
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 static inline int
 __xfrm6_selector_match(struct xfrm_selector *sel, struct flowi *fl)
 {
@@ -527,6 +528,7 @@
                (fl->proto == sel->proto || !sel->proto) &&
                (fl->oif == sel->ifindex || !sel->ifindex);
 }
+#endif
 
 static inline int
 xfrm_selector_match(struct xfrm_selector *sel, struct flowi *fl,
@@ -535,8 +537,10 @@
        switch (family) {
        case AF_INET:
                return __xfrm4_selector_match(sel, fl);
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
        case AF_INET6:
                return __xfrm6_selector_match(sel, fl);
+#endif
        }
        return 0;
 }
@@ -577,7 +581,9 @@
                struct xfrm_dst         *next;
                struct dst_entry        dst;
                struct rtable           rt;
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
                struct rt6_info         rt6;
+#endif
        } u;
        struct dst_entry *route;
        u32 genid;
@@ -650,12 +656,14 @@
                 tmpl->saddr.a4 != x->props.saddr.a4);
 }
 
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 static inline int
 __xfrm6_state_addr_cmp(struct xfrm_tmpl *tmpl, struct xfrm_state *x)
 {
        return  (!ipv6_addr_any((struct in6_addr*)&tmpl->saddr) &&
                 ipv6_addr_cmp((struct in6_addr *)&tmpl->saddr, (struct 
in6_addr*)&x->props.saddr));
 }
+#endif
 
 static inline int
 xfrm_state_addr_cmp(struct xfrm_tmpl *tmpl, struct xfrm_state *x, unsigned 
short family)
@@ -663,8 +671,10 @@
        switch (family) {
        case AF_INET:
                return __xfrm4_state_addr_cmp(tmpl, x);
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
        case AF_INET6:
                return __xfrm6_state_addr_cmp(tmpl, x);
+#endif
        }
        return !0;
 }
@@ -762,8 +772,10 @@
        switch (family){
        case AF_INET:
                return (xfrm_address_t *)&fl->fl4_dst;
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
        case AF_INET6:
                return (xfrm_address_t *)&fl->fl6_dst;
+#endif
        }
        return NULL;
 }
@@ -774,8 +786,10 @@
        switch (family){
        case AF_INET:
                return (xfrm_address_t *)&fl->fl4_src;
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
        case AF_INET6:
                return (xfrm_address_t *)&fl->fl6_src;
+#endif
        }
        return NULL;
 }
@@ -790,6 +804,7 @@
        return 0;
 }
 
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 static __inline__ int
 __xfrm6_state_addr_check(struct xfrm_state *x,
                         xfrm_address_t *daddr, xfrm_address_t *saddr)
@@ -801,6 +816,7 @@
                return 1;
        return 0;
 }
+#endif
 
 static __inline__ int
 xfrm_state_addr_check(struct xfrm_state *x,
@@ -810,8 +826,10 @@
        switch (family) {
        case AF_INET:
                return __xfrm4_state_addr_check(x, daddr, saddr);
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
        case AF_INET6:
                return __xfrm6_state_addr_check(x, daddr, saddr);
+#endif
        }
        return 0;
 }
@@ -825,10 +843,12 @@
                return __xfrm4_state_addr_check(x,
                                                (xfrm_address_t *)&fl->fl4_dst,
                                                (xfrm_address_t *)&fl->fl4_src);
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
        case AF_INET6:
                return __xfrm6_state_addr_check(x,
                                                (xfrm_address_t *)&fl->fl6_dst,
                                                (xfrm_address_t *)&fl->fl6_src);
+#endif
        }
        return 0;
 }