Attachment 218723 Details for Bug 248652 – Draft patch to test the netmap tx timer

[patch] Draft patch to test the netmap tx timer

txsync.diff (text/plain), 6.82 KB, created by Vincenzo Maffione on 2020-10-13 21:14:32 UTC

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Creator: Vincenzo Maffione

Created: 2020-10-13 21:14:32 UTC

Size: 6.82 KB

patch

obsolete

>diff --git a/sys/net/iflib.c b/sys/net/iflib.c
>index 85c29f850..40abce781 100644
>--- a/sys/net/iflib.c
>+++ b/sys/net/iflib.c
>@@ -190,6 +190,7 @@ struct iflib_ctx {
> 	uint16_t ifc_sysctl_nrxqs;
> 	uint16_t ifc_sysctl_qs_eq_override;
> 	uint16_t ifc_sysctl_rx_budget;
>+	uint16_t ifc_sysctl_nm_tx_tmr_us;
> 	uint16_t ifc_sysctl_tx_abdicate;
> 	uint16_t ifc_sysctl_core_offset;
> #define	CORE_OFFSET_UNSPECIFIED	0xffff
>@@ -346,6 +347,9 @@ struct iflib_txq {
> 	qidx_t		ift_size;
> 	uint16_t	ift_id;
> 	struct callout	ift_timer;
>+#ifdef DEV_NETMAP
>+	struct callout	ift_netmap_timer;
>+#endif /* DEV_NETMAP */
> 
> 	if_txsd_vec_t	ift_sds;
> 	uint8_t		ift_qstatus;
>@@ -753,6 +757,7 @@ iflib_num_tx_descs(if_ctx_t ctx)
> MODULE_DEPEND(iflib, netmap, 1, 1, 1);
> 
> static int netmap_fl_refill(iflib_rxq_t rxq, struct netmap_kring *kring, bool init);
>+static void iflib_netmap_timer(void *arg);
> 
> /*
>  * device-specific sysctl variables:
>@@ -1060,9 +1065,14 @@ iflib_netmap_txsync(struct netmap_kring *kring, int flags)
> 	}
> 	if (!(ctx->ifc_flags & IFC_NETMAP_TX_IRQ))
> 		if (kring->nr_hwtail != nm_prev(kring->nr_hwcur, lim)) {
>-			callout_reset_on(&txq->ift_timer, hz < 2000 ? 1 : hz / 1000,
>-			    iflib_timer, txq, txq->ift_timer.c_cpu);
>-	}
>+			uint16_t timer_us = ctx->ifc_sysctl_nm_tx_tmr_us;
>+
>+			if (timer_us == 0)
>+				timer_us = 500;
>+			callout_reset_sbt(&txq->ift_netmap_timer,
>+			    timer_us * SBT_1US, SBT_1US, iflib_netmap_timer,
>+			    txq, 0);
>+		}
> 	return (0);
> }
> 
>@@ -1263,28 +1273,12 @@ iflib_netmap_rxq_init(if_ctx_t ctx, iflib_rxq_t rxq)
> }
> 
> static void
>-iflib_netmap_timer_adjust(if_ctx_t ctx, iflib_txq_t txq, uint32_t *reset_on)
>+iflib_netmap_timer(void *arg)
> {
>-	struct netmap_kring *kring;
>-	uint16_t txqid;
>-
>-	txqid = txq->ift_id;
>-	kring = netmap_kring_on(NA(ctx->ifc_ifp), txqid, NR_TX);
>-	if (kring == NULL)
>-		return;
>+	iflib_txq_t txq = arg;
>+	if_ctx_t ctx = txq->ift_ctx;
> 
>-	if (kring->nr_hwcur != nm_next(kring->nr_hwtail, kring->nkr_num_slots - 1)) {
>-		bus_dmamap_sync(txq->ift_ifdi->idi_tag, txq->ift_ifdi->idi_map,
>-		    BUS_DMASYNC_POSTREAD);
>-		if (ctx->isc_txd_credits_update(ctx->ifc_softc, txqid, false))
>-			netmap_tx_irq(ctx->ifc_ifp, txqid);
>-		if (!(ctx->ifc_flags & IFC_NETMAP_TX_IRQ)) {
>-			if (hz < 2000)
>-				*reset_on = 1;
>-			else
>-				*reset_on = hz / 1000;
>-		}
>-	}
>+	netmap_tx_irq(ctx->ifc_ifp, txq->ift_id);
> }
> 
> #define iflib_netmap_detach(ifp) netmap_detach(ifp)
>@@ -1296,8 +1290,6 @@ iflib_netmap_timer_adjust(if_ctx_t ctx, iflib_txq_t txq, uint32_t *reset_on)
> 
> #define iflib_netmap_attach(ctx) (0)
> #define netmap_rx_irq(ifp, qid, budget) (0)
>-#define netmap_tx_irq(ifp, qid) do {} while (0)
>-#define iflib_netmap_timer_adjust(ctx, txq, reset_on)
> #endif
> 
> #if defined(__i386__) || defined(__amd64__)
>@@ -2287,7 +2279,6 @@ iflib_timer(void *arg)
> 	if_ctx_t ctx = txq->ift_ctx;
> 	if_softc_ctx_t sctx = &ctx->ifc_softc_ctx;
> 	uint64_t this_tick = ticks;
>-	uint32_t reset_on = hz / 2;
> 
> 	if (!(if_getdrvflags(ctx->ifc_ifp) & IFF_DRV_RUNNING))
> 		return;
>@@ -2312,17 +2303,13 @@ iflib_timer(void *arg)
> 		}
> 		txq->ift_cleaned_prev = txq->ift_cleaned;
> 	}
>-#ifdef DEV_NETMAP
>-	if (if_getcapenable(ctx->ifc_ifp) & IFCAP_NETMAP)
>-		iflib_netmap_timer_adjust(ctx, txq, &reset_on);
>-#endif
> 	/* handle any laggards */
> 	if (txq->ift_db_pending)
> 		GROUPTASK_ENQUEUE(&txq->ift_task);
> 
> 	sctx->isc_pause_frames = 0;
> 	if (if_getdrvflags(ctx->ifc_ifp) & IFF_DRV_RUNNING) 
>-		callout_reset_on(&txq->ift_timer, reset_on, iflib_timer, txq, txq->ift_timer.c_cpu);
>+		callout_reset_on(&txq->ift_timer, hz / 2, iflib_timer, txq, txq->ift_timer.c_cpu);
> 	return;
> 
>  hung:
>@@ -2396,6 +2383,9 @@ iflib_init_locked(if_ctx_t ctx)
> 	for (i = 0, txq = ctx->ifc_txqs; i < sctx->isc_ntxqsets; i++, txq++) {
> 		CALLOUT_LOCK(txq);
> 		callout_stop(&txq->ift_timer);
>+#ifdef DEV_NETMAP
>+		callout_stop(&txq->ift_netmap_timer);
>+#endif /* DEV_NETMAP */
> 		CALLOUT_UNLOCK(txq);
> 		iflib_netmap_txq_init(ctx, txq);
> 	}
>@@ -2485,6 +2475,9 @@ iflib_stop(if_ctx_t ctx)
> 
> 		CALLOUT_LOCK(txq);
> 		callout_stop(&txq->ift_timer);
>+#ifdef DEV_NETMAP
>+		callout_stop(&txq->ift_netmap_timer);
>+#endif /* DEV_NETMAP */
> 		CALLOUT_UNLOCK(txq);
> 
> 		/* clean any enqueued buffers */
>@@ -3882,7 +3875,6 @@ _task_fn_admin(void *context)
> 	iflib_txq_t txq;
> 	int i;
> 	bool oactive, running, do_reset, do_watchdog, in_detach;
>-	uint32_t reset_on = hz / 2;
> 
> 	STATE_LOCK(ctx);
> 	running = (if_getdrvflags(ctx->ifc_ifp) & IFF_DRV_RUNNING);
>@@ -3910,12 +3902,7 @@ _task_fn_admin(void *context)
> 	}
> 	IFDI_UPDATE_ADMIN_STATUS(ctx);
> 	for (txq = ctx->ifc_txqs, i = 0; i < sctx->isc_ntxqsets; i++, txq++) {
>-#ifdef DEV_NETMAP
>-		reset_on = hz / 2;
>-		if (if_getcapenable(ctx->ifc_ifp) & IFCAP_NETMAP)
>-			iflib_netmap_timer_adjust(ctx, txq, &reset_on);
>-#endif
>-		callout_reset_on(&txq->ift_timer, reset_on, iflib_timer, txq, txq->ift_timer.c_cpu);
>+		callout_reset_on(&txq->ift_timer, hz / 2, iflib_timer, txq, txq->ift_timer.c_cpu);
> 	}
> 	IFDI_LINK_INTR_ENABLE(ctx);
> 	if (do_reset)
>@@ -5088,6 +5075,9 @@ iflib_pseudo_deregister(if_ctx_t ctx)
> 	tqg = qgroup_if_io_tqg;
> 	for (txq = ctx->ifc_txqs, i = 0; i < NTXQSETS(ctx); i++, txq++) {
> 		callout_drain(&txq->ift_timer);
>+#ifdef DEV_NETMAP
>+		callout_drain(&txq->ift_netmap_timer);
>+#endif /* DEV_NETMAP */
> 		if (txq->ift_task.gt_uniq != NULL)
> 			taskqgroup_detach(tqg, &txq->ift_task);
> 	}
>@@ -5174,6 +5164,9 @@ iflib_device_deregister(if_ctx_t ctx)
> 	tqg = qgroup_if_io_tqg;
> 	for (txq = ctx->ifc_txqs, i = 0; i < NTXQSETS(ctx); i++, txq++) {
> 		callout_drain(&txq->ift_timer);
>+#ifdef DEV_NETMAP
>+		callout_drain(&txq->ift_netmap_timer);
>+#endif /* DEV_NETMAP */
> 		if (txq->ift_task.gt_uniq != NULL)
> 			taskqgroup_detach(tqg, &txq->ift_task);
> 	}
>@@ -5583,8 +5576,6 @@ iflib_queues_alloc(if_ctx_t ctx)
> 		} else {
> 			txq->ift_br_offset = 0;
> 		}
>-		/* XXX fix this */
>-		txq->ift_timer.c_cpu = cpu;
> 
> 		if (iflib_txsd_alloc(txq)) {
> 			device_printf(dev, "Critical Failure setting up TX buffers\n");
>@@ -5597,6 +5588,9 @@ iflib_queues_alloc(if_ctx_t ctx)
> 		    device_get_nameunit(dev), txq->ift_id);
> 		mtx_init(&txq->ift_mtx, txq->ift_mtx_name, NULL, MTX_DEF);
> 		callout_init_mtx(&txq->ift_timer, &txq->ift_mtx, 0);
>+#ifdef DEV_NETMAP
>+		callout_init_mtx(&txq->ift_netmap_timer, &txq->ift_mtx, 0);
>+#endif /* DEV_NETMAP */
> 
> 		err = ifmp_ring_alloc(&txq->ift_br, 2048, txq, iflib_txq_drain,
> 				      iflib_txq_can_drain, M_IFLIB, M_WAITOK);
>@@ -6610,6 +6604,9 @@ iflib_add_device_sysctl_pre(if_ctx_t ctx)
> 	SYSCTL_ADD_U16(ctx_list, oid_list, OID_AUTO, "rx_budget",
> 		       CTLFLAG_RWTUN, &ctx->ifc_sysctl_rx_budget, 0,
> 		       "set the RX budget");
>+	SYSCTL_ADD_U16(ctx_list, oid_list, OID_AUTO, "nm_tx_tmr_us",
>+		       CTLFLAG_RWTUN, &ctx->ifc_sysctl_nm_tx_tmr_us, 0,
>+		       "set the TX netmap timer period");
> 	SYSCTL_ADD_U16(ctx_list, oid_list, OID_AUTO, "tx_abdicate",
> 		       CTLFLAG_RWTUN, &ctx->ifc_sysctl_tx_abdicate, 0,
> 		       "cause TX to abdicate instead of running to completion");

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Attachments on bug 248652: 218723 | 218866 | 218932 | 219062 | 219121 | 219179