From: Sepherosa Ziehau <sephe@dragonflybsd.org>
Date: Wed, 1 Aug 2012 09:09:58 +0000 (+0800)
Subject: emx: Add EMX_TSO_DEBUG
X-Git-Tag: v3.2.0~484
X-Git-Url: http://gitweb.dragonflybsd.org/dragonfly.git/commitdiff_plain/0c0e1638b808d58479e41e5cd14e1354db2154b5

emx: Add EMX_TSO_DEBUG

It is used to measure TSO context reuse rate.  Setting up TX context
interferes TX data fetching pipelining, thus reduces performance, so
TX context setting up should be avoided as much as possible.

According to limited measurement:
- 1 one direction TX stream, reuse rate is ~40%
- 16 one direction TX streams, reuse rate is ~20%
- 16 bi-direction streams (total 32), reuse rate is ~10%
---

diff --git a/sys/conf/options b/sys/conf/options
index 5c0a22e..052eb09 100644
--- a/sys/conf/options
+++ b/sys/conf/options
@@ -625,6 +625,7 @@ ED_NO_MIIBUS		opt_ed.h
 
 # emx driver
 EMX_RSS_DEBUG		opt_emx.h
+EMX_TSO_DEBUG		opt_emx.h
 
 # jme driver
 JME_RSS_DEBUG		opt_jme.h
diff --git a/sys/config/LINT b/sys/config/LINT
index d661e04..5851173 100644
--- a/sys/config/LINT
+++ b/sys/config/LINT
@@ -2497,6 +2497,7 @@ options 	DEBUG_INTERRUPTS
 options		BCE_DEBUG
 options		BNX_TSO_DEBUG
 options		EMX_RSS_DEBUG
+options		EMX_TSO_DEBUG
 options		JME_RSS_DEBUG
 options		IGB_RSS_DEBUG
 options		IGB_MSIX_DEBUG
diff --git a/sys/config/LINT64 b/sys/config/LINT64
index e24a3dc..a5068fd 100644
--- a/sys/config/LINT64
+++ b/sys/config/LINT64
@@ -2260,6 +2260,7 @@ options 	DEBUG_INTERRUPTS
 options		BCE_DEBUG
 options		BNX_TSO_DEBUG
 options		EMX_RSS_DEBUG
+options		EMX_TSO_DEBUG
 options		JME_RSS_DEBUG
 options		IGB_RSS_DEBUG
 options		IGB_MSIX_DEBUG
diff --git a/sys/dev/netif/emx/if_emx.c b/sys/dev/netif/emx/if_emx.c
index be6eca1..31d907c 100644
--- a/sys/dev/netif/emx/if_emx.c
+++ b/sys/dev/netif/emx/if_emx.c
@@ -3229,6 +3229,9 @@ emx_print_debug_info(struct emx_softc *sc)
 	    sc->dropped_pkts);
 	device_printf(dev, "Driver tx dma failure in encap = %ld\n",
 	    sc->no_tx_dma_setup);
+
+	device_printf(dev, "TSO segments %lu\n", sc->tso_segments);
+	device_printf(dev, "TSO ctx reused %lu\n", sc->tso_ctx_reused);
 }
 
 static void
@@ -3795,6 +3798,10 @@ emx_tso_setup(struct emx_softc *sc, struct mbuf *mp,
 	int mss, pktlen, curr_txd;
 	struct ip *ip;
 
+#ifdef EMX_TSO_DEBUG
+	sc->tso_segments++;
+#endif
+
 	iphlen = mp->m_pkthdr.csum_iphlen;
 	thoff = mp->m_pkthdr.csum_thlen;
 	hoff = mp->m_pkthdr.csum_lhlen;
@@ -3812,6 +3819,9 @@ emx_tso_setup(struct emx_softc *sc, struct mbuf *mp,
 	    sc->csum_pktlen == pktlen) {
 		*txd_upper = sc->csum_txd_upper;
 		*txd_lower = sc->csum_txd_lower;
+#ifdef EMX_TSO_DEBUG
+		sc->tso_ctx_reused++;
+#endif
 		return 0;
 	}
 	hlen = hoff + iphlen + thoff;
diff --git a/sys/dev/netif/emx/if_emx.h b/sys/dev/netif/emx/if_emx.h
index 5ac32d9..acd377c 100644
--- a/sys/dev/netif/emx/if_emx.h
+++ b/sys/dev/netif/emx/if_emx.h
@@ -365,6 +365,8 @@ struct emx_softc {
 	unsigned long		rx_irq;
 	unsigned long		tx_irq;
 	unsigned long		link_irq;
+	unsigned long		tso_segments;
+	unsigned long		tso_ctx_reused;
 
 	/* sysctl tree glue */
 	struct sysctl_ctx_list	sysctl_ctx;