From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: [PATCH] net: Use __this_cpu_inc() in fast path Date: Thu, 20 May 2010 10:07:23 +0200 Message-ID: <1274342843.4046.16.camel@edumazet-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev To: David Miller Return-path: Received: from mail-fx0-f46.google.com ([209.85.161.46]:52261 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750877Ab0ETIH2 (ORCPT ); Thu, 20 May 2010 04:07:28 -0400 Received: by fxm10 with SMTP id 10so3212567fxm.19 for ; Thu, 20 May 2010 01:07:26 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: This patch saves 224 bytes of text on my machine. __this_cpu_inc() generates a single instruction, using no scratch registers : 65 ff 04 25 a8 30 01 00 incl %gs:0x130a8 instead of : 48 c7 c2 80 30 01 00 mov $0x13080,%rdx 65 48 8b 04 25 88 ea 00 00 mov %gs:0xea88,%rax 83 44 10 28 01 addl $0x1,0x28(%rax,%rdx,1) Signed-off-by: Eric Dumazet --- net/core/dev.c | 3 +-- net/ipv4/route.c | 3 +-- 2 files changed, 2 insertions(+), 4 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index 6c82065..76475f2 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2826,8 +2826,7 @@ static int __netif_receive_skb(struct sk_buff *skb) skb->dev = master; } - __get_cpu_var(softnet_data).processed++; - + __this_cpu_inc(softnet_data.processed); skb_reset_network_header(skb); skb_reset_transport_header(skb); skb->mac_len = skb->network_header - skb->mac_header; diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 560acc6..8495bce 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -253,8 +253,7 @@ static unsigned rt_hash_mask __read_mostly; static unsigned int rt_hash_log __read_mostly; static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); -#define RT_CACHE_STAT_INC(field) \ - (__raw_get_cpu_var(rt_cache_stat).field++) +#define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field) static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx, int genid)