diff mbox series

[net-next,20/20] net: move early demux fields close to sk_refcnt

Message ID 20211115190249.3936899-21-eric.dumazet@gmail.com (mailing list archive)
State Accepted
Delegated to: Netdev Maintainers
Headers show
Series tcp: optimizations for linux-5.17 | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count fail Series longer than 15 patches (and no cover letter)
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 3054 this patch: 3054
netdev/cc_maintainers success CCed 3 of 3 maintainers
netdev/build_clang success Errors and warnings before: 423 this patch: 423
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 3190 this patch: 3190
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 20 lines checked
netdev/kdoc success Errors and warnings before: 1 this patch: 1
netdev/source_inline success Was 0 now: 0

Commit Message

Eric Dumazet Nov. 15, 2021, 7:02 p.m. UTC 
From: Eric Dumazet <edumazet@google.com>

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>
---
 include/net/sock.h | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/include/net/sock.h b/include/net/sock.h
index 2578d1f455a7af0d7f4ce5d3b4ac25ee41fdaeb4..95cc03bd3fac0f3f5ea49bfd540a1f0eda4ebf59 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;