As IPPROTO_TCP is 6, it makes sense to make sure inet_protos[] array is properly cache line aligned to avoid false sharing on SMP.
c0680540 b peer_total c0680544 b inet_peer_unused_head c0680560 B inet_protos On i386 this example, we can see that inet_protos[IPPROTO_TCP] shares a potentially hot (and modified) cache line. Signed-off-by: Eric Dumazet <[EMAIL PROTECTED]> diff --git a/net/ipv4/protocol.c b/net/ipv4/protocol.c index da70fef..971ab93 100644 --- a/net/ipv4/protocol.c +++ b/net/ipv4/protocol.c @@ -45,7 +45,7 @@ #include <net/udp.h> #include <net/ipip.h> #include <linux/igmp.h> -struct net_protocol *inet_protos[MAX_INET_PROTOS]; +struct net_protocol *inet_protos[MAX_INET_PROTOS] ____cacheline_aligned_in_smp; static DEFINE_SPINLOCK(inet_proto_lock); /* - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
