From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Horman Subject: [PATCH 8/9] ipvs: optimize the use of flags in ip_vs_bind_dest Date: Wed, 21 Mar 2012 17:56:23 +0900 Message-ID: <1332320185-27157-9-git-send-email-horms@verge.net.au> References: <1332320185-27157-1-git-send-email-horms@verge.net.au> Cc: lvs-devel@vger.kernel.org, netdev@vger.kernel.org, netfilter-devel@vger.kernel.org, Wensong Zhang , Julian Anastasov , Simon Horman To: Pablo Neira Ayuso Return-path: In-Reply-To: <1332320185-27157-1-git-send-email-horms@verge.net.au> Sender: netfilter-devel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Julian Anastasov cp->flags is marked volatile but ip_vs_bind_dest can safely modify the flags, so save some CPU cycles by using temp variable. Signed-off-by: Julian Anastasov Signed-off-by: Simon Horman --- net/netfilter/ipvs/ip_vs_conn.c | 15 +++++++++------ 1 files changed, 9 insertions(+), 6 deletions(-) diff --git a/net/netfilter/ipvs/ip_vs_conn.c b/net/netfilter/ipvs/ip_vs_conn.c index 7478b66..1eaec99 100644 --- a/net/netfilter/ipvs/ip_vs_conn.c +++ b/net/netfilter/ipvs/ip_vs_conn.c @@ -548,6 +548,7 @@ static inline void ip_vs_bind_dest(struct ip_vs_conn *cp, struct ip_vs_dest *dest) { unsigned int conn_flags; + __u32 flags; /* if dest is NULL, then return directly */ if (!dest) @@ -559,17 +560,19 @@ ip_vs_bind_dest(struct ip_vs_conn *cp, struct ip_vs_dest *dest) conn_flags = atomic_read(&dest->conn_flags); if (cp->protocol != IPPROTO_UDP) conn_flags &= ~IP_VS_CONN_F_ONE_PACKET; + flags = cp->flags; /* Bind with the destination and its corresponding transmitter */ - if (cp->flags & IP_VS_CONN_F_SYNC) { + if (flags & IP_VS_CONN_F_SYNC) { /* if the connection is not template and is created * by sync, preserve the activity flag. */ - if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) + if (!(flags & IP_VS_CONN_F_TEMPLATE)) conn_flags &= ~IP_VS_CONN_F_INACTIVE; /* connections inherit forwarding method from dest */ - cp->flags &= ~(IP_VS_CONN_F_FWD_MASK | IP_VS_CONN_F_NOOUTPUT); + flags &= ~(IP_VS_CONN_F_FWD_MASK | IP_VS_CONN_F_NOOUTPUT); } - cp->flags |= conn_flags; + flags |= conn_flags; + cp->flags = flags; cp->dest = dest; IP_VS_DBG_BUF(7, "Bind-dest %s c:%s:%d v:%s:%d " @@ -584,11 +587,11 @@ ip_vs_bind_dest(struct ip_vs_conn *cp, struct ip_vs_dest *dest) atomic_read(&dest->refcnt)); /* Update the connection counters */ - if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) { + if (!(flags & IP_VS_CONN_F_TEMPLATE)) { /* It is a normal connection, so modify the counters * according to the flags, later the protocol can * update them on state change */ - if (!(cp->flags & IP_VS_CONN_F_INACTIVE)) + if (!(flags & IP_VS_CONN_F_INACTIVE)) atomic_inc(&dest->activeconns); else atomic_inc(&dest->inactconns); -- 1.7.6.3