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: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2021-11-15 11:02:49 -08:00 committed by David S. Miller
parent 29fbc26e6d
commit 43f51df417
1 changed files with 5 additions and 3 deletions

View File

@ -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;