Commit f9e2511d authored by Breno Leitao's avatar Breno Leitao Committed by Jakub Kicinski
Browse files

netdevsim: migrate to dstats stats collection 



Replace custom statistics tracking with the kernel's dstats infrastructure
to simplify code and improve consistency with other network drivers.

This change:
- Sets dev->pcpu_stat_type = NETDEV_PCPU_STAT_DSTATS for automatic
  automatic allocation and deallocation.
- Removes manual stats fields and their update
- Replaces custom nsim_get_stats64() with dev_get_stats()
- Uses dev_dstats_tx_add() and dev_dstats_tx_dropped() helpers
- Eliminates the need for manual synchronization primitives

The dstats framework provides the same functionality with less code.

Suggested-by: default avatarJakub Kicinski <kuba@kernel.org>
Reviewed-by: default avatarJoe Damato <joe@dama.to>
Signed-off-by: default avatarBreno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20250618-netdevsim_stat-v4-1-19fe0d35e28e@debian.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent c3ee72de

drivers/net/netdevsim/netdev.c

+6 −27
Original line number Diff line number Diff line
@@ -93,19 +93,14 @@ static netdev_tx_t nsim_start_xmit(struct sk_buff *skb, struct net_device *dev) 
		hrtimer_start(&rq->napi_timer, us_to_ktime(5), HRTIMER_MODE_REL);



	rcu_read_unlock();

	u64_stats_update_begin(&ns->syncp);

	ns->tx_packets++;

	ns->tx_bytes += len;

	u64_stats_update_end(&ns->syncp);

	dev_dstats_tx_add(dev, skb->len);

	return NETDEV_TX_OK;



out_drop_free:

	dev_kfree_skb(skb);

out_drop_cnt:

	rcu_read_unlock();

	u64_stats_update_begin(&ns->syncp);

	ns->tx_dropped++;

	u64_stats_update_end(&ns->syncp);

	dev_dstats_tx_dropped(dev);

	return NETDEV_TX_OK;

}
@@ -126,20 +121,6 @@ static int nsim_change_mtu(struct net_device *dev, int new_mtu) 
	return 0;

}



static void

nsim_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)

{

	struct netdevsim *ns = netdev_priv(dev);

	unsigned int start;



	do {

		start = u64_stats_fetch_begin(&ns->syncp);

		stats->tx_bytes = ns->tx_bytes;

		stats->tx_packets = ns->tx_packets;

		stats->tx_dropped = ns->tx_dropped;

	} while (u64_stats_fetch_retry(&ns->syncp, start));

}



static int

nsim_setup_tc_block_cb(enum tc_setup_type type, void *type_data, void *cb_priv)

{
@@ -556,7 +537,6 @@ static const struct net_device_ops nsim_netdev_ops = { 
	.ndo_set_mac_address	= eth_mac_addr,

	.ndo_validate_addr	= eth_validate_addr,

	.ndo_change_mtu		= nsim_change_mtu,

	.ndo_get_stats64	= nsim_get_stats64,

	.ndo_set_vf_mac		= nsim_set_vf_mac,

	.ndo_set_vf_vlan	= nsim_set_vf_vlan,

	.ndo_set_vf_rate	= nsim_set_vf_rate,
@@ -580,7 +560,6 @@ static const struct net_device_ops nsim_vf_netdev_ops = { 
	.ndo_set_mac_address	= eth_mac_addr,

	.ndo_validate_addr	= eth_validate_addr,

	.ndo_change_mtu		= nsim_change_mtu,

	.ndo_get_stats64	= nsim_get_stats64,

	.ndo_setup_tc		= nsim_setup_tc,

	.ndo_set_features	= nsim_set_features,

};
@@ -594,7 +573,7 @@ static void nsim_get_queue_stats_rx(struct net_device *dev, int idx, 
	struct rtnl_link_stats64 rtstats = {};



	if (!idx)

		nsim_get_stats64(dev, &rtstats);

		dev_get_stats(dev, &rtstats);



	stats->packets = rtstats.rx_packets - !!rtstats.rx_packets;

	stats->bytes = rtstats.rx_bytes;
@@ -606,7 +585,7 @@ static void nsim_get_queue_stats_tx(struct net_device *dev, int idx, 
	struct rtnl_link_stats64 rtstats = {};



	if (!idx)

		nsim_get_stats64(dev, &rtstats);

		dev_get_stats(dev, &rtstats);



	stats->packets = rtstats.tx_packets - !!rtstats.tx_packets;

	stats->bytes = rtstats.tx_bytes;
@@ -618,7 +597,7 @@ static void nsim_get_base_stats(struct net_device *dev, 
{

	struct rtnl_link_stats64 rtstats = {};



	nsim_get_stats64(dev, &rtstats);

	dev_get_stats(dev, &rtstats);



	rx->packets = !!rtstats.rx_packets;

	rx->bytes = 0;
@@ -890,6 +869,7 @@ static void nsim_setup(struct net_device *dev) 
			    NETIF_F_HW_CSUM |

			    NETIF_F_LRO |

			    NETIF_F_TSO;

	dev->pcpu_stat_type = NETDEV_PCPU_STAT_DSTATS;

	dev->max_mtu = ETH_MAX_MTU;

	dev->xdp_features = NETDEV_XDP_ACT_HW_OFFLOAD;

}
@@ -1022,7 +1002,6 @@ nsim_create(struct nsim_dev *nsim_dev, struct nsim_dev_port *nsim_dev_port) 
	dev_net_set(dev, nsim_dev_net(nsim_dev));

	ns = netdev_priv(dev);

	ns->netdev = dev;

	u64_stats_init(&ns->syncp);

	ns->nsim_dev = nsim_dev;

	ns->nsim_dev_port = nsim_dev_port;

	ns->nsim_bus_dev = nsim_dev->nsim_bus_dev;

drivers/net/netdevsim/netdevsim.h

+0 −5
Original line number Diff line number Diff line
@@ -108,11 +108,6 @@ struct netdevsim { 


	int rq_reset_mode;



	u64 tx_packets;

	u64 tx_bytes;

	u64 tx_dropped;

	struct u64_stats_sync syncp;



	struct nsim_bus_dev *nsim_bus_dev;



	struct bpf_prog	*bpf_offloaded;