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authorYOSHIFUJI Hideaki / 吉藤英明 <yoshfuji@linux-ipv6.org>2010-03-31 22:24:22 +0000
committerDavid S. Miller <davem@davemloft.net>2010-04-01 18:41:41 -0700
commitbd2c77a0a749589b45f2697ea446a4438d078f9b (patch)
tree801d2f87cad4bd6bafd946ad4eb16cb1c0db779b
parent152102c7f2bf191690f1069bae292ea3925adf14 (diff)
downloadop-kernel-dev-bd2c77a0a749589b45f2697ea446a4438d078f9b.zip
op-kernel-dev-bd2c77a0a749589b45f2697ea446a4438d078f9b.tar.gz
ipv6 fib: Make rt6_info{} more cache-line aware.
The head element of rt6_info{} is dst_entry{}, and IPv6 specific elements follow. Because elements at the end of dst_entry{} are frequently updated, it is not good to put frequently-used static elements, such as rt6i_idev, rt6i_dst or rt6i_flags in the same cache line. On the other hand, fib6_table, rt6i_node or rt6i_gateway are rarely used, so it is okay to stay in the same cache line. Let's rearrange rt6_info{}. Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/net/ip6_fib.h29
1 files changed, 16 insertions, 13 deletions
diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index 86f46c4..4b1dc11 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -88,34 +88,37 @@ struct rt6_info {
struct dst_entry dst;
} u;
- struct inet6_dev *rt6i_idev;
-
#define rt6i_dev u.dst.dev
#define rt6i_nexthop u.dst.neighbour
#define rt6i_expires u.dst.expires
+ /*
+ * Tail elements of dst_entry (__refcnt etc.)
+ * and these elements (rarely used in hot path) are in
+ * the same cache line.
+ */
+ struct fib6_table *rt6i_table;
struct fib6_node *rt6i_node;
struct in6_addr rt6i_gateway;
-
- u32 rt6i_flags;
- u32 rt6i_metric;
- atomic_t rt6i_ref;
- /* more non-fragment space at head required */
- unsigned short rt6i_nfheader_len;
-
- u8 rt6i_protocol;
+ atomic_t rt6i_ref;
- struct fib6_table *rt6i_table;
+ /* These are in a separate cache line. */
+ struct rt6key rt6i_dst ____cacheline_aligned_in_smp;
+ u32 rt6i_flags;
+ struct rt6key rt6i_src;
+ u32 rt6i_metric;
- struct rt6key rt6i_dst;
+ struct inet6_dev *rt6i_idev;
#ifdef CONFIG_XFRM
u32 rt6i_flow_cache_genid;
#endif
+ /* more non-fragment space at head required */
+ unsigned short rt6i_nfheader_len;
- struct rt6key rt6i_src;
+ u8 rt6i_protocol;
};
static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
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