[NET]: Reorder fields of struct dst_entry This last patch (but not least :) ) finally moves the next pointer at the end of struct dst_entry. This permits to perform route cache lookups with a minimal cost of one cache line per entry, instead of two. Both 32bits and 64bits platforms benefit from this new layout. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- commit 1e19e02ca0c5e33ea73a25127dbe6c3b8fcaac4b tree 23afba2945a9e09b137b094a868ea176c1e1c800 parent 0c195c3fc4e95a06b0c0017506f074c94af99c35 author Eric Dumazet Fri, 09 Feb 2007 16:26:55 -0800 committer David S. Miller Sat, 10 Feb 2007 23:20:45 -0800 include/net/dst.h | 20 ++++++++++---------- 1 files changed, 10 insertions(+), 10 deletions(-) diff --git a/include/net/dst.h b/include/net/dst.h index 5d62342..e12a8ce 100644 --- a/include/net/dst.h +++ b/include/net/dst.h @@ -37,14 +37,7 @@ struct sk_buff; struct dst_entry { - union { - struct dst_entry *next; - struct rtable *rt_next; - struct rt6_info *rt6_next; - struct dn_route *dn_next; - }; - atomic_t __refcnt; /* client references */ - int __use; + struct rcu_head rcu_head; struct dst_entry *child; struct net_device *dev; short error; @@ -55,7 +48,6 @@ struct dst_entry #define DST_NOPOLICY 4 #define DST_NOHASH 8 #define DST_BALANCED 0x10 - unsigned long lastuse; unsigned long expires; unsigned short header_len; /* more space at head required */ @@ -80,8 +72,16 @@ struct dst_entry #endif struct dst_ops *ops; - struct rcu_head rcu_head; + unsigned long lastuse; + atomic_t __refcnt; /* client references */ + int __use; + union { + struct dst_entry *next; + struct rtable *rt_next; + struct rt6_info *rt6_next; + struct dn_route *dn_next; + }; char info[0]; };