Attachment 232471 Details for Bug 262571 – Patch that works around the problem

[patch] Patch that works around the problem

epair.patch (text/plain), 3.04 KB, created by Michael Gmelin on 2022-03-15 14:08:19 UTC

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Creator: Michael Gmelin

Created: 2022-03-15 14:08:19 UTC

Size: 3.04 KB

patch

obsolete

>diff --git a/sys/net/if_epair.c b/sys/net/if_epair.c
>index 818f25f0c..36c37b84f 100644
>--- a/sys/net/if_epair.c
>+++ b/sys/net/if_epair.c
>@@ -98,11 +98,15 @@ static unsigned int next_index = 0;
> #define	EPAIR_LOCK()			mtx_lock(&epair_n_index_mtx)
> #define	EPAIR_UNLOCK()			mtx_unlock(&epair_n_index_mtx)
> 
>+#define BIT_QUEUE_TASK		0
>+#define BIT_MBUF_QUEUED		1
>+
> struct epair_softc;
> struct epair_queue {
> 	int			 id;
> 	struct buf_ring		*rxring[2];
> 	volatile int		 ridx;		/* 0 || 1 */
>+	volatile int		 state;		/* queue state */
> 	struct task		 tx_task;
> 	struct epair_softc	*sc;
> };
>@@ -171,7 +175,8 @@ epair_tx_start_deferred(void *arg, int pending)
> 	} while (!atomic_fcmpset_int(&q->ridx, &ridx, nidx));
> 	epair_if_input(sc, q, ridx);
> 
>-	if (! buf_ring_empty(q->rxring[nidx]))
>+	atomic_clear_int(&q->state, (1 << BIT_QUEUE_TASK));
>+	if (atomic_testandclear_int(&q->state, BIT_MBUF_QUEUED))
> 		taskqueue_enqueue(epair_tasks.tq[q->id], &q->tx_task);
> 
> 	if_rele(sc->ifp);
>@@ -186,7 +191,6 @@ epair_menq(struct mbuf *m, struct epair_softc *osc)
> 	short mflags;
> 	struct epair_queue *q = NULL;
> 	uint32_t bucket;
>-	bool was_empty;
> #ifdef RSS
> 	struct ether_header *eh;
> #endif
>@@ -234,8 +238,8 @@ epair_menq(struct mbuf *m, struct epair_softc *osc)
> #endif
> 	q = &osc->queues[bucket];
> 
>+	atomic_set_int(&q->state, (1 << BIT_MBUF_QUEUED));
> 	ridx = atomic_load_int(&q->ridx);
>-	was_empty = buf_ring_empty(q->rxring[ridx]);
> 	ret = buf_ring_enqueue(q->rxring[ridx], m);
> 	if (ret != 0) {
> 		/* Ring is full. */
>@@ -256,10 +260,11 @@ epair_menq(struct mbuf *m, struct epair_softc *osc)
> 	/* Someone else received the packet. */
> 	if_inc_counter(oifp, IFCOUNTER_IPACKETS, 1);
> 
>-done:
>-	if (was_empty)
>+	if (!atomic_testandset_int(&q->state, BIT_QUEUE_TASK)) {
> 		taskqueue_enqueue(epair_tasks.tq[bucket], &q->tx_task);
>+	}
> 
>+done:
> 	return (0);
> }
> 
>@@ -304,9 +309,11 @@ epair_transmit(struct ifnet *ifp, struct mbuf *m)
> {
> 	struct epair_softc *sc;
> 	struct ifnet *oifp;
>-	int error, len;
>+	int error;
>+#ifdef ALTQ
>+	int len;
> 	short mflags;
>-
>+#endif
> 	if (m == NULL)
> 		return (0);
> 	M_ASSERTPKTHDR(m);
>@@ -342,10 +349,11 @@ epair_transmit(struct ifnet *ifp, struct mbuf *m)
> 		m_freem(m);
> 		return (0);
> 	}
>+
>+#ifdef ALTQ
> 	len = m->m_pkthdr.len;
> 	mflags = m->m_flags;
> 
>-#ifdef ALTQ
> 	/* Support ALTQ via the classic if_start() path. */
> 	IF_LOCK(&ifp->if_snd);
> 	if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
>@@ -538,6 +546,7 @@ epair_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
> 		q->rxring[0] = buf_ring_alloc(RXRSIZE, M_EPAIR, M_WAITOK, NULL);
> 		q->rxring[1] = buf_ring_alloc(RXRSIZE, M_EPAIR, M_WAITOK, NULL);
> 		q->ridx = 0;
>+		q->state = 0;
> 		q->sc = sca;
> 		NET_TASK_INIT(&q->tx_task, 0, epair_tx_start_deferred, q);
> 	}
>@@ -560,6 +569,7 @@ epair_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
> 		q->rxring[0] = buf_ring_alloc(RXRSIZE, M_EPAIR, M_WAITOK, NULL);
> 		q->rxring[1] = buf_ring_alloc(RXRSIZE, M_EPAIR, M_WAITOK, NULL);
> 		q->ridx = 0;
>+		q->state = 0;
> 		q->sc = scb;
> 		NET_TASK_INIT(&q->tx_task, 0, epair_tx_start_deferred, q);
> 	}

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Attachments on bug 262571: 232471