From 43f51df4172955971ef5498f09308a9dc0291766 Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@google.com>
Date: Mon, 15 Nov 2021 11:02:49 -0800
Subject: [PATCH] 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>
---
include/net/sock.h | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/include/net/sock.h b/include/net/sock.h
index 2578d1f455a7a..95cc03bd3fac0 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -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;
--
2.30.2