diff mbox series

[v2,net-next,04/10] net: avoid dirtying sk->sk_rx_queue_mapping

Message ID 20211025164825.259415-5-eric.dumazet@gmail.com (mailing list archive)
State Accepted
Commit 342159ee394d103db4bea1b01f932c50e66be163
Delegated to: Netdev Maintainers
Headers show
Series tcp: receive path optimizations | expand

Checks

Context Check Description
netdev/cover_letter success Series has a cover letter
netdev/fixes_present success Fixes tag not required for -next series
netdev/patch_count success Link
netdev/tree_selection success Clearly marked for net-next
netdev/subject_prefix success Link
netdev/cc_maintainers success CCed 3 of 3 maintainers
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 3051 this patch: 3051
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success No Fixes tag
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 12 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 3135 this patch: 3135
netdev/header_inline success No static functions without inline keyword in header files

Commit Message

Eric Dumazet Oct. 25, 2021, 4:48 p.m. UTC 
From: Eric Dumazet <edumazet@google.com>

sk_rx_queue_mapping is located in a cache line that should be kept read mostly.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
---
 include/net/sock.h | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/include/net/sock.h b/include/net/sock.h
index 99c4194cb61add848e3a35db0f952c4193f5ea1f..b4d3744b188ad869b4ec55f78e04236b710898de 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1916,10 +1916,8 @@  static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb)
 	if (skb_rx_queue_recorded(skb)) {
 		u16 rx_queue = skb_get_rx_queue(skb);
 
-		if (WARN_ON_ONCE(rx_queue == NO_QUEUE_MAPPING))
-			return;
-
-		sk->sk_rx_queue_mapping = rx_queue;
+		if (unlikely(READ_ONCE(sk->sk_rx_queue_mapping) != rx_queue))
+			WRITE_ONCE(sk->sk_rx_queue_mapping, rx_queue);
 	}
 #endif
 }