sfxge: expect required init_state on data path and in periodic calls

With the patch applied the number of instruction events is 1% less and
number of mispredicted branch events is 5% less under multistream TCP
traffic load close to line rate.

Sponsored by:   Solarflare Communications, Inc.
Approved by:    gnn (mentor)

5 files changed, 18 insertions, 17 deletions

diff --git a/sys/dev/sfxge/sfxge_ev.c b/sys/dev/sfxge/sfxge_ev.c
index 237d472..83bdf26 100644
--- a/sys/dev/sfxge/sfxge_ev.c
+++ b/sys/dev/sfxge/sfxge_ev.c
@@ -103,7 +103,7 @@ sfxge_ev_rx(void *arg, uint32_t label, uint32_t id, uint32_t size,
 	KASSERT(evq->index == rxq->index,
 	    ("evq->index != rxq->index"));
 
-	if (rxq->init_state != SFXGE_RXQ_STARTED)
+	if (__predict_false(rxq->init_state != SFXGE_RXQ_STARTED))
 		goto done;
 
 	expected = rxq->pending++ & rxq->ptr_mask;
@@ -256,7 +256,7 @@ sfxge_ev_tx(void *arg, uint32_t label, uint32_t id)
 	KASSERT(evq->index == txq->evq_index,
 	    ("evq->index != txq->evq_index"));
 
-	if (txq->init_state != SFXGE_TXQ_STARTED)
+	if (__predict_false(txq->init_state != SFXGE_TXQ_STARTED))
 		goto done;
 
 	stop = (id + 1) & txq->ptr_mask;
@@ -433,7 +433,7 @@ sfxge_ev_stat_update(struct sfxge_softc *sc)
 
 	SFXGE_ADAPTER_LOCK(sc);
 
-	if (sc->evq[0]->init_state != SFXGE_EVQ_STARTED)
+	if (__predict_false(sc->evq[0]->init_state != SFXGE_EVQ_STARTED))
 		goto out;
 
 	now = ticks;
@@ -598,8 +598,8 @@ sfxge_ev_qpoll(struct sfxge_evq *evq)
 
 	SFXGE_EVQ_LOCK(evq);
 
-	if (evq->init_state != SFXGE_EVQ_STARTING &&
-	    evq->init_state != SFXGE_EVQ_STARTED) {
+	if (__predict_false(evq->init_state != SFXGE_EVQ_STARTING &&
+			    evq->init_state != SFXGE_EVQ_STARTED)) {
 		rc = EINVAL;
 		goto fail;
 	}
diff --git a/sys/dev/sfxge/sfxge_intr.c b/sys/dev/sfxge/sfxge_intr.c
index 9773a24..240a33f 100644
--- a/sys/dev/sfxge/sfxge_intr.c
+++ b/sys/dev/sfxge/sfxge_intr.c
@@ -134,7 +134,7 @@ sfxge_intr_message(void *arg)
 	KASSERT(intr->type == EFX_INTR_MESSAGE,
 	    ("intr->type != EFX_INTR_MESSAGE"));
 
-	if (intr->state != SFXGE_INTR_STARTED)
+	if (__predict_false(intr->state != SFXGE_INTR_STARTED))
 		return;
 
 	(void)efx_intr_status_message(enp, index, &fatal);
diff --git a/sys/dev/sfxge/sfxge_port.c b/sys/dev/sfxge/sfxge_port.c
index 00925af..691e5b5 100644
--- a/sys/dev/sfxge/sfxge_port.c
+++ b/sys/dev/sfxge/sfxge_port.c
@@ -50,7 +50,7 @@ sfxge_mac_stat_update(struct sfxge_softc *sc)
 
 	SFXGE_PORT_LOCK_ASSERT_OWNED(port);
 
-	if (port->init_state != SFXGE_PORT_STARTED) {
+	if (__predict_false(port->init_state != SFXGE_PORT_STARTED)) {
 		rc = 0;
 		goto out;
 	}
@@ -241,7 +241,7 @@ sfxge_port_wanted_fc_handler(SYSCTL_HANDLER_ARGS)
 		SFXGE_PORT_LOCK(port);
 
 		if (port->wanted_fc != fcntl) {
-			if (port->init_state == SFXGE_PORT_STARTED)
+		    if (__predict_false(port->init_state == SFXGE_PORT_STARTED))
 				error = efx_mac_fcntl_set(sc->enp,
 							  port->wanted_fc,
 							  B_TRUE);
@@ -272,7 +272,8 @@ sfxge_port_link_fc_handler(SYSCTL_HANDLER_ARGS)
 	port = &sc->port;
 
 	SFXGE_PORT_LOCK(port);
-	if (port->init_state == SFXGE_PORT_STARTED && SFXGE_LINK_UP(sc))
+	if (__predict_true(port->init_state == SFXGE_PORT_STARTED) &&
+	    SFXGE_LINK_UP(sc))
 		efx_mac_fcntl_get(sc->enp, &wanted_fc, &link_fc);
 	else
 		link_fc = 0;
@@ -327,7 +328,7 @@ sfxge_mac_poll_work(void *arg, int npending)
 
 	SFXGE_PORT_LOCK(port);
 
-	if (port->init_state != SFXGE_PORT_STARTED)
+	if (__predict_false(port->init_state != SFXGE_PORT_STARTED))
 		goto done;
 
 	/* This may sleep waiting for MCDI completion */
@@ -394,7 +395,7 @@ sfxge_mac_filter_set(struct sfxge_softc *sc)
 	 * lock is held in sleeping thread. Both problems are repeatable
 	 * on LAG with LACP proto bring up.
 	 */
-	if (port->init_state == SFXGE_PORT_STARTED)
+	if (__predict_true(port->init_state == SFXGE_PORT_STARTED))
 		rc = sfxge_mac_filter_set_locked(sc);
 	else
 		rc = 0;
@@ -518,7 +519,7 @@ sfxge_phy_stat_update(struct sfxge_softc *sc)
 
 	SFXGE_PORT_LOCK_ASSERT_OWNED(port);
 
-	if (port->init_state != SFXGE_PORT_STARTED) {
+	if (__predict_false(port->init_state != SFXGE_PORT_STARTED)) {
 		rc = 0;
 		goto out;
 	}
diff --git a/sys/dev/sfxge/sfxge_rx.c b/sys/dev/sfxge/sfxge_rx.c
index e73dc7d..1d98142 100644
--- a/sys/dev/sfxge/sfxge_rx.c
+++ b/sys/dev/sfxge/sfxge_rx.c
@@ -209,7 +209,7 @@ sfxge_rx_qfill(struct sfxge_rxq *rxq, unsigned int target, boolean_t retrying)
 
 	SFXGE_EVQ_LOCK_ASSERT_OWNED(evq);
 
-	if (rxq->init_state != SFXGE_RXQ_STARTED)
+	if (__predict_false(rxq->init_state != SFXGE_RXQ_STARTED))
 		return;
 
 	rxfill = rxq->added - rxq->completed;
@@ -269,7 +269,7 @@ void
 sfxge_rx_qrefill(struct sfxge_rxq *rxq)
 {
 
-	if (rxq->init_state != SFXGE_RXQ_STARTED)
+	if (__predict_false(rxq->init_state != SFXGE_RXQ_STARTED))
 		return;
 
 	/* Make sure the queue is full */
@@ -760,7 +760,7 @@ sfxge_rx_qcomplete(struct sfxge_rxq *rxq, boolean_t eop)
 		rx_desc = &rxq->queue[id];
 		m = rx_desc->mbuf;
 
-		if (rxq->init_state != SFXGE_RXQ_STARTED)
+		if (__predict_false(rxq->init_state != SFXGE_RXQ_STARTED))
 			goto discard;
 
 		if (rx_desc->flags & (EFX_ADDR_MISMATCH | EFX_DISCARD))
diff --git a/sys/dev/sfxge/sfxge_tx.c b/sys/dev/sfxge/sfxge_tx.c
index 7622086..6600123 100644
--- a/sys/dev/sfxge/sfxge_tx.c
+++ b/sys/dev/sfxge/sfxge_tx.c
@@ -311,7 +311,7 @@ static int sfxge_tx_queue_mbuf(struct sfxge_txq *txq, struct mbuf *mbuf)
 	if (mbuf->m_pkthdr.csum_flags & CSUM_TSO)
 		prefetch_read_many(mbuf->m_data);
 
-	if (txq->init_state != SFXGE_TXQ_STARTED) {
+	if (__predict_false(txq->init_state != SFXGE_TXQ_STARTED)) {
 		rc = EINTR;
 		goto reject;
 	}
@@ -1143,7 +1143,7 @@ sfxge_tx_qunblock(struct sfxge_txq *txq)
 
 	SFXGE_EVQ_LOCK_ASSERT_OWNED(evq);
 
-	if (txq->init_state != SFXGE_TXQ_STARTED)
+	if (__predict_false(txq->init_state != SFXGE_TXQ_STARTED))
 		return;
 
 	SFXGE_TXQ_LOCK(txq);