Commit 23fa6a23 authored by Jakub Kicinski's avatar Jakub Kicinski Committed by Paolo Abeni
Browse files

net: export a helper for adding up queue stats 



Older drivers and drivers with lower queue counts often have a static
array of queues, rather than allocating structs for each queue on demand.
Add a helper for adding up qstats from a queue range. Expectation is
that driver will pass a queue range [netdev->real_num_*x_queues, MAX).
It was tempting to always use num_*x_queues as the end, but virtio
seems to clamp its queue count after allocating the netdev. And this
way we can trivaly reuse the helper for [0, real_..).

Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
Link: https://patch.msgid.link/20250507003221.823267-2-kuba@kernel.org


Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 95d2f258

include/net/netdev_queues.h

+6 −0
Original line number Diff line number Diff line
@@ -103,6 +103,12 @@ struct netdev_stat_ops { 
			       struct netdev_queue_stats_tx *tx);

};



void netdev_stat_queue_sum(struct net_device *netdev,

			   int rx_start, int rx_end,

			   struct netdev_queue_stats_rx *rx_sum,

			   int tx_start, int tx_end,

			   struct netdev_queue_stats_tx *tx_sum);



/**

 * struct netdev_queue_mgmt_ops - netdev ops for queue management

 *

net/core/netdev-genl.c

+50 −19
Original line number Diff line number Diff line
@@ -708,25 +708,66 @@ netdev_nl_stats_by_queue(struct net_device *netdev, struct sk_buff *rsp, 
	return 0;

}



/**

 * netdev_stat_queue_sum() - add up queue stats from range of queues

 * @netdev:	net_device

 * @rx_start:	index of the first Rx queue to query

 * @rx_end:	index after the last Rx queue (first *not* to query)

 * @rx_sum:	output Rx stats, should be already initialized

 * @tx_start:	index of the first Tx queue to query

 * @tx_end:	index after the last Tx queue (first *not* to query)

 * @tx_sum:	output Tx stats, should be already initialized

 *

 * Add stats from [start, end) range of queue IDs to *x_sum structs.

 * The sum structs must be already initialized. Usually this

 * helper is invoked from the .get_base_stats callbacks of drivers

 * to account for stats of disabled queues. In that case the ranges

 * are usually [netdev->real_num_*x_queues, netdev->num_*x_queues).

 */

void netdev_stat_queue_sum(struct net_device *netdev,

			   int rx_start, int rx_end,

			   struct netdev_queue_stats_rx *rx_sum,

			   int tx_start, int tx_end,

			   struct netdev_queue_stats_tx *tx_sum)

{

	const struct netdev_stat_ops *ops;

	struct netdev_queue_stats_rx rx;

	struct netdev_queue_stats_tx tx;

	int i;



	ops = netdev->stat_ops;



	for (i = rx_start; i < rx_end; i++) {

		memset(&rx, 0xff, sizeof(rx));

		if (ops->get_queue_stats_rx)

			ops->get_queue_stats_rx(netdev, i, &rx);

		netdev_nl_stats_add(rx_sum, &rx, sizeof(rx));

	}

	for (i = tx_start; i < tx_end; i++) {

		memset(&tx, 0xff, sizeof(tx));

		if (ops->get_queue_stats_tx)

			ops->get_queue_stats_tx(netdev, i, &tx);

		netdev_nl_stats_add(tx_sum, &tx, sizeof(tx));

	}

}

EXPORT_SYMBOL(netdev_stat_queue_sum);



static int

netdev_nl_stats_by_netdev(struct net_device *netdev, struct sk_buff *rsp,

			  const struct genl_info *info)

{

	struct netdev_queue_stats_rx rx_sum, rx;

	struct netdev_queue_stats_tx tx_sum, tx;

	const struct netdev_stat_ops *ops;

	struct netdev_queue_stats_rx rx_sum;

	struct netdev_queue_stats_tx tx_sum;

	void *hdr;

	int i;



	ops = netdev->stat_ops;

	/* Netdev can't guarantee any complete counters */

	if (!ops->get_base_stats)

	if (!netdev->stat_ops->get_base_stats)

		return 0;



	memset(&rx_sum, 0xff, sizeof(rx_sum));

	memset(&tx_sum, 0xff, sizeof(tx_sum));



	ops->get_base_stats(netdev, &rx_sum, &tx_sum);

	netdev->stat_ops->get_base_stats(netdev, &rx_sum, &tx_sum);



	/* The op was there, but nothing reported, don't bother */

	if (!memchr_inv(&rx_sum, 0xff, sizeof(rx_sum)) &&
@@ -739,18 +780,8 @@ netdev_nl_stats_by_netdev(struct net_device *netdev, struct sk_buff *rsp, 
	if (nla_put_u32(rsp, NETDEV_A_QSTATS_IFINDEX, netdev->ifindex))

		goto nla_put_failure;



	for (i = 0; i < netdev->real_num_rx_queues; i++) {

		memset(&rx, 0xff, sizeof(rx));

		if (ops->get_queue_stats_rx)

			ops->get_queue_stats_rx(netdev, i, &rx);

		netdev_nl_stats_add(&rx_sum, &rx, sizeof(rx));

	}

	for (i = 0; i < netdev->real_num_tx_queues; i++) {

		memset(&tx, 0xff, sizeof(tx));

		if (ops->get_queue_stats_tx)

			ops->get_queue_stats_tx(netdev, i, &tx);

		netdev_nl_stats_add(&tx_sum, &tx, sizeof(tx));

	}

	netdev_stat_queue_sum(netdev, 0, netdev->real_num_rx_queues, &rx_sum,

			      0, netdev->real_num_tx_queues, &tx_sum);



	if (netdev_nl_stats_write_rx(rsp, &rx_sum) ||

	    netdev_nl_stats_write_tx(rsp, &tx_sum))