Commit c353c7b7 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net-device: move lstats in net_device_read_txrx 



dev->lstats is notably used from loopback ndo_start_xmit()
and other virtual drivers.

Per cpu stats updates are dirtying per-cpu data,
but the pointer itself is read-only.

Fixes: 43a71cd6 ("net-device: reorganize net_device fast path variables")
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Coco Li <lixiaoyan@google.com>
Cc: Simon Horman <horms@kernel.org>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 666a877d

Documentation/networking/net_cachelines/net_device.rst

+2 −2
Original line number Diff line number Diff line
@@ -136,8 +136,8 @@ struct_netpoll_info* npinfo - 
possible_net_t                      nd_net                  -                   read_mostly         (dev_net)napi_busy_loop,tcp_v(4/6)_rcv,ip(v6)_rcv,ip(6)_input,ip(6)_input_finish

void*                               ml_priv                                                         

enum_netdev_ml_priv_type            ml_priv_type                                                    

struct_pcpu_lstats__percpu*         lstats                                                          

struct_pcpu_sw_netstats__percpu*    tstats                                                          

struct_pcpu_lstats__percpu*         lstats                  read_mostly                             dev_lstats_add()

struct_pcpu_sw_netstats__percpu*    tstats                  read_mostly                             dev_sw_netstats_tx_add()

struct_pcpu_dstats__percpu*         dstats                                                          

struct_garp_port*                   garp_port                                                       

struct_mrp_port*                    mrp_port

include/linux/netdevice.h

+5 −5
Original line number Diff line number Diff line
@@ -2141,6 +2141,11 @@ struct net_device { 


	/* TXRX read-mostly hotpath */

	__cacheline_group_begin(net_device_read_txrx);

	union {

		struct pcpu_lstats __percpu		*lstats;

		struct pcpu_sw_netstats __percpu	*tstats;

		struct pcpu_dstats __percpu		*dstats;

	};

	unsigned int		flags;

	unsigned short		hard_header_len;

	netdev_features_t	features;
@@ -2395,11 +2400,6 @@ struct net_device { 
	enum netdev_ml_priv_type	ml_priv_type;



	enum netdev_stat_type		pcpu_stat_type:8;

	union {

		struct pcpu_lstats __percpu		*lstats;

		struct pcpu_sw_netstats __percpu	*tstats;

		struct pcpu_dstats __percpu		*dstats;

	};



#if IS_ENABLED(CONFIG_GARP)

	struct garp_port __rcu	*garp_port;

net/core/dev.c

+2 −1
Original line number Diff line number Diff line
@@ -11652,11 +11652,12 @@ static void __init net_dev_struct_check(void) 
	CACHELINE_ASSERT_GROUP_SIZE(struct net_device, net_device_read_tx, 160);



	/* 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, 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, 30);

	CACHELINE_ASSERT_GROUP_SIZE(struct net_device, net_device_read_txrx, 38);



	/* RX read-mostly hotpath */

	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, ptype_specific);