Commit 3715b5df authored Jun 30, 2025 by Eric Dumazet Committed by Jakub Kicinski Jul 02, 2025

net: add struct net_aligned_data



This structure will hold networking data that must
consume a full cache line to avoid accidental false sharing.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250630093540.3052835-2-edumazet@google.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

parent a8065af3

include/net/aligned_data.h

0 → 100644

+16 −0

Original line number	Diff line number	Diff line
		/* SPDX-License-Identifier: GPL-2.0-or-later */
		#ifndef _NET_ALIGNED_DATA_H
		#define _NET_ALIGNED_DATA_H

		#include <linux/types.h>

		/* Structure holding cacheline aligned fields on SMP builds.
		* Each field or group should have an ____cacheline_aligned_in_smp
		* attribute to ensure no accidental false sharing can happen.
		*/
		struct net_aligned_data {
		};

		extern struct net_aligned_data net_aligned_data;

		#endif /* _NET_ALIGNED_DATA_H */

net/core/hotdata.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -2,6 +2,7 @@
		#include <linux/cache.h>
		#include <linux/jiffies.h>
		#include <linux/list.h>
		#include <net/aligned_data.h>
		#include <net/hotdata.h>
		#include <net/proto_memory.h>

		@@ -22,3 +23,5 @@ struct net_hotdata net_hotdata __cacheline_aligned = {
		.sysctl_mem_pcpu_rsv = SK_MEMORY_PCPU_RESERVE
		};
		EXPORT_SYMBOL(net_hotdata);

		struct net_aligned_data net_aligned_data;