[PATCH net] net: move dev->state into net_device_read_txrx group

[PATCH net] net: move dev->state into net_device_read_txrx group

[Eric Dumazet]

dev->state can be read in rx and tx fast paths.

netif_running() which needs dev->state is called from
- enqueue_to_backlog() [RX path]
- __dev_direct_xmit()  [TX path]

Fixes: 43a71cd66b9c ("net-device: reorganize net_device fast path variables")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Coco Li <lixiaoyan@google.com>
---
 Documentation/networking/net_cachelines/net_device.rst | 2 +-
 include/linux/netdevice.h                              | 2 +-
 net/core/dev.c                                         | 3 ++-
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/Documentation/networking/net_cachelines/net_device.rst b/Documentation/networking/net_cachelines/net_device.rst
index dceb49d56a91158232543e920c7ed23bed74106e..70c4fb9d4e5ce0feb0d82578b878da3dbd00a7fb 100644
--- a/Documentation/networking/net_cachelines/net_device.rst
+++ b/Documentation/networking/net_cachelines/net_device.rst
@@ -13,7 +13,7 @@ struct_dev_ifalias*                 ifalias
 unsigned_long                       mem_end                                                         
 unsigned_long                       mem_start                                                       
 unsigned_long                       base_addr                                                       
-unsigned_long                       state                                                           
+unsigned_long                       state                   read_mostly         read_mostly         netif_running(dev)
 struct_list_head                    dev_list                                                        
 struct_list_head                    napi_list                                                       
 struct_list_head                    unreg_list                                                      
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index c6f6ac779b34ef1a8f98853c84a7a2e0192e0e8f..cb37817d6382c29117afd8ce54db6dba94f8c930 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2072,6 +2072,7 @@ struct net_device {
 		struct pcpu_sw_netstats __percpu	*tstats;
 		struct pcpu_dstats __percpu		*dstats;
 	};
+	unsigned long		state;
 	unsigned int		flags;
 	unsigned short		hard_header_len;
 	netdev_features_t	features;
@@ -2117,7 +2118,6 @@ struct net_device {
 	 *	part of the usual set specified in Space.c.
 	 */
 
-	unsigned long		state;
 
 	struct list_head	dev_list;
 	struct list_head	napi_list;
diff --git a/net/core/dev.c b/net/core/dev.c
index 0766a245816bdf70f6609dc7b6d694ae81e7a9e5..8db23b3c55f10a98870b2b4b9c403bbf48c41d77 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -11665,11 +11665,12 @@ static void __init net_dev_struct_check(void)
 
 	/* TXRX read-mostly hotpath */
 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_txrx, lstats);
+	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_txrx, state);
 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_txrx, flags);
 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_txrx, hard_header_len);
 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_txrx, features);
 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_txrx, ip6_ptr);
-	CACHELINE_ASSERT_GROUP_SIZE(struct net_device, net_device_read_txrx, 38);
+	CACHELINE_ASSERT_GROUP_SIZE(struct net_device, net_device_read_txrx, 46);
 
 	/* RX read-mostly hotpath */
 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, ptype_specific);
-- 
2.44.0.291.gc1ea87d7ee-goog

Re: [PATCH net] net: move dev->state into net_device_read_txrx group

[Jiri Pirko]

Thu, Mar 14, 2024 at 09:08:45PM CET, edumazet@google.com wrote:
>dev->state can be read in rx and tx fast paths.
>
>netif_running() which needs dev->state is called from
>- enqueue_to_backlog() [RX path]
>- __dev_direct_xmit()  [TX path]
>
>Fixes: 43a71cd66b9c ("net-device: reorganize net_device fast path variables")
>Signed-off-by: Eric Dumazet <edumazet@google.com>

Reviewed-by: Jiri Pirko <jiri@nvidia.com>

Re: [PATCH net] net: move dev->state into net_device_read_txrx group

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (main)
by Paolo Abeni <pabeni@redhat.com>:

On Thu, 14 Mar 2024 20:08:45 +0000 you wrote:
> dev->state can be read in rx and tx fast paths.
> 
> netif_running() which needs dev->state is called from
> - enqueue_to_backlog() [RX path]
> - __dev_direct_xmit()  [TX path]
> 
> Fixes: 43a71cd66b9c ("net-device: reorganize net_device fast path variables")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Cc: Coco Li <lixiaoyan@google.com>
> 
> [...]

Here is the summary with links:
  - [net] net: move dev->state into net_device_read_txrx group
    https://git.kernel.org/netdev/net/c/f6e0a4984c2e

You are awesome, thank you!
-- 
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