Commit 2a68a223 authored by Breno Leitao's avatar Breno Leitao Committed by Jakub Kicinski
Browse files

netdevsim: account dropped packet length in stats on queue free 

Add a call to dev_dstats_rx_dropped_add() in nsim_queue_free() to
account for the number of packets dropped when purging the skb queue.
This improves the accuracy of RX drop statistics reported by netdevsim.

local_bh_{disable, enable}() protection is used to disable preemption,
which is necessary given that dev_dstats_rx_dropped_add() access
this_cpu_ptr(). See discussion in [1].

Link: https://lore.kernel.org/all/20250617055934.3fd9d322@kernel.org/

 [1]
Suggested-by: default avatarJakub Kicinski <kuba@kernel.org>
Signed-off-by: default avatarBreno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20250618-netdevsim_stat-v4-4-19fe0d35e28e@debian.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 27480a7c

drivers/net/netdevsim/netdev.c

+7 −4
Original line number Diff line number Diff line
@@ -632,9 +632,12 @@ static struct nsim_rq *nsim_queue_alloc(void) 
	return rq;

}



static void nsim_queue_free(struct nsim_rq *rq)

static void nsim_queue_free(struct net_device *dev, struct nsim_rq *rq)

{

	hrtimer_cancel(&rq->napi_timer);

	local_bh_disable();

	dev_dstats_rx_dropped_add(dev, rq->skb_queue.qlen);

	local_bh_enable();

	skb_queue_purge_reason(&rq->skb_queue, SKB_DROP_REASON_QUEUE_PURGE);

	kfree(rq);

}
@@ -681,7 +684,7 @@ nsim_queue_mem_alloc(struct net_device *dev, void *per_queue_mem, int idx) 
	return 0;



err_free:

	nsim_queue_free(qmem->rq);

	nsim_queue_free(dev, qmem->rq);

	return err;

}
@@ -695,7 +698,7 @@ static void nsim_queue_mem_free(struct net_device *dev, void *per_queue_mem) 
		if (!ns->rq_reset_mode)

			netif_napi_del_locked(&qmem->rq->napi);

		page_pool_destroy(qmem->rq->page_pool);

		nsim_queue_free(qmem->rq);

		nsim_queue_free(dev, qmem->rq);

	}

}
@@ -913,7 +916,7 @@ static void nsim_queue_uninit(struct netdevsim *ns) 
	int i;



	for (i = 0; i < dev->num_rx_queues; i++)

		nsim_queue_free(ns->rq[i]);

		nsim_queue_free(dev, ns->rq[i]);



	kfree(ns->rq);

	ns->rq = NULL;