net: optimize INET input path further
Followup of commit b178bb3dfc30 (net: reorder struct sock fields)
Optimize INET input path a bit further, by :
1) moving sk_refcnt close to sk_lock.
This reduces number of dirtied cache lines by one on 64bit arches (and
64 bytes cache line size).
2) moving inet_daddr & inet_rcv_saddr at the beginning of sk
(same cache line than hash / family / bound_dev_if / nulls_node)
This reduces number of accessed cache lines in lookups by one, and dont
increase size of inet and timewait socks.
inet and tw sockets now share same place-holder for these fields.
Before patch :
offsetof(struct sock, sk_refcnt) = 0x10
offsetof(struct sock, sk_lock) = 0x40
offsetof(struct sock, sk_receive_queue) = 0x60
offsetof(struct inet_sock, inet_daddr) = 0x270
offsetof(struct inet_sock, inet_rcv_saddr) = 0x274
After patch :
offsetof(struct sock, sk_refcnt) = 0x44
offsetof(struct sock, sk_lock) = 0x48
offsetof(struct sock, sk_receive_queue) = 0x68
offsetof(struct inet_sock, inet_daddr) = 0x0
offsetof(struct inet_sock, inet_rcv_saddr) = 0x4
compute_score() (udp or tcp) now use a single cache line per ignored
item, instead of two.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/inet_timewait_sock.h b/include/net/inet_timewait_sock.h
index a066fdd..17404b5 100644
--- a/include/net/inet_timewait_sock.h
+++ b/include/net/inet_timewait_sock.h
@@ -88,12 +88,6 @@
extern void inet_twdr_twkill_work(struct work_struct *work);
extern void inet_twdr_twcal_tick(unsigned long data);
-#if (BITS_PER_LONG == 64)
-#define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 8
-#else
-#define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 4
-#endif
-
struct inet_bind_bucket;
/*
@@ -117,15 +111,15 @@
#define tw_hash __tw_common.skc_hash
#define tw_prot __tw_common.skc_prot
#define tw_net __tw_common.skc_net
+#define tw_daddr __tw_common.skc_daddr
+#define tw_rcv_saddr __tw_common.skc_rcv_saddr
int tw_timeout;
volatile unsigned char tw_substate;
- /* 3 bits hole, try to pack */
unsigned char tw_rcv_wscale;
+
/* Socket demultiplex comparisons on incoming packets. */
- /* these five are in inet_sock */
+ /* these three are in inet_sock */
__be16 tw_sport;
- __be32 tw_daddr __attribute__((aligned(INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES)));
- __be32 tw_rcv_saddr;
__be16 tw_dport;
__u16 tw_num;
kmemcheck_bitfield_begin(flags);
@@ -191,10 +185,10 @@
return (struct inet_timewait_sock *)sk;
}
-static inline __be32 inet_rcv_saddr(const struct sock *sk)
+static inline __be32 sk_rcv_saddr(const struct sock *sk)
{
- return likely(sk->sk_state != TCP_TIME_WAIT) ?
- inet_sk(sk)->inet_rcv_saddr : inet_twsk(sk)->tw_rcv_saddr;
+/* both inet_sk() and inet_twsk() store rcv_saddr in skc_rcv_saddr */
+ return sk->__sk_common.skc_rcv_saddr;
}
extern void inet_twsk_put(struct inet_timewait_sock *tw);