Commit 43f51df4 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net: move early demux fields close to sk_refcnt 



sk_rx_dst/sk_rx_dst_ifindex/sk_rx_dst_cookie are read in early demux,
and currently spans two cache lines.

Moving them close to sk_refcnt makes more sense, as only one cache
line is needed.

New layout for this hot cache line is :

struct sock {
	struct sock_common         __sk_common;          /*     0  0x88 */
	/* --- cacheline 2 boundary (128 bytes) was 8 bytes ago --- */
	struct dst_entry *         sk_rx_dst;            /*  0x88   0x8 */
	int                        sk_rx_dst_ifindex;    /*  0x90   0x4 */
	u32                        sk_rx_dst_cookie;     /*  0x94   0x4 */
	socket_lock_t              sk_lock;              /*  0x98  0x20 */
	atomic_t                   sk_drops;             /*  0xb8   0x4 */
	int                        sk_rcvlowat;          /*  0xbc   0x4 */
	/* --- cacheline 3 boundary (192 bytes) --- */

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 29fbc26e

include/net/sock.h

+5 −3
Original line number Diff line number Diff line
@@ -390,6 +390,11 @@ struct sock { 
#define sk_flags		__sk_common.skc_flags

#define sk_rxhash		__sk_common.skc_rxhash



	/* early demux fields */

	struct dst_entry	*sk_rx_dst;

	int			sk_rx_dst_ifindex;

	u32			sk_rx_dst_cookie;



	socket_lock_t		sk_lock;

	atomic_t		sk_drops;

	int			sk_rcvlowat;
@@ -432,9 +437,6 @@ struct sock { 
#ifdef CONFIG_XFRM

	struct xfrm_policy __rcu *sk_policy[2];

#endif

	struct dst_entry	*sk_rx_dst;

	int			sk_rx_dst_ifindex;

	u32			sk_rx_dst_cookie;



	struct dst_entry __rcu	*sk_dst_cache;

	atomic_t		sk_omem_alloc;