net: Use __this_cpu_inc() in fast path (27f39c73) · Commits · 戴 / test

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 <eric.dumazet@gmail.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/core/dev.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -2822,8 +2822,7 @@ 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;

net/ipv4/route.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -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)

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