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[src/trunk]: src/sys/dev/pci - Add some instrumentation which can be enabled ...
details: https://anonhg.NetBSD.org/src/rev/0a662c6771b1
branches: trunk
changeset: 510059:0a662c6771b1
user: thorpej <thorpej%NetBSD.org@localhost>
date: Fri May 18 04:38:30 2001 +0000
description:
- Add some instrumentation which can be enabled by defining
SIP_EVENT_COUNTERS.
- Decrease SIP_NTXSEGS to 8 and increase SIP_TXQUEUELEN to 256.
This gives us 256 transmit jobs with only twice the descriptor
memory footprint. This prevents stalling transmissions due to
lack of transmit jobs under heavy load.
- Increase SIP_NRXDESC to 128 so we don't run out of receive descriptors
under extreme load.
- As recommended by the manual, leave one descriptor in the transmit ring
with OWN clear to prevent wrap-around.
- Even though the manual claims that driver software must initialize
TXDP if there are no pending transmissions when a new transmission
is to be initialized, doing so causes serious performance degredation
on the DP83820 under heavy load. Not initializing TXDP also increases
performance on the DP83815.
All of this gets us up to ~90Mb/s on both the DP83820 and DP83815 when
connected to a 100base network.
diffstat:
sys/dev/pci/if_sip.c | 80 +++++++++++++++++++++++++++++++++++++++++++++------
1 files changed, 70 insertions(+), 10 deletions(-)
diffs (174 lines):
diff -r cf15cc496c0f -r 0a662c6771b1 sys/dev/pci/if_sip.c
--- a/sys/dev/pci/if_sip.c Fri May 18 02:07:34 2001 +0000
+++ b/sys/dev/pci/if_sip.c Fri May 18 04:38:30 2001 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: if_sip.c,v 1.29 2001/05/18 02:03:53 thorpej Exp $ */
+/* $NetBSD: if_sip.c,v 1.30 2001/05/18 04:38:30 thorpej Exp $ */
/*-
* Copyright (c) 2001 The NetBSD Foundation, Inc.
@@ -147,12 +147,12 @@
/*
* Transmit descriptor list size. This is arbitrary, but allocate
- * enough descriptors for 64 pending transmissions, and 16 segments
+ * enough descriptors for 128 pending transmissions, and 8 segments
* per packet. This MUST work out to a power of 2.
*/
-#define SIP_NTXSEGS 16
+#define SIP_NTXSEGS 8
-#define SIP_TXQUEUELEN 64
+#define SIP_TXQUEUELEN 256
#define SIP_NTXDESC (SIP_TXQUEUELEN * SIP_NTXSEGS)
#define SIP_NTXDESC_MASK (SIP_NTXDESC - 1)
#define SIP_NEXTTX(x) (((x) + 1) & SIP_NTXDESC_MASK)
@@ -161,7 +161,7 @@
* Receive descriptor list size. We have one Rx buffer per incoming
* packet, so this logic is a little simpler.
*/
-#define SIP_NRXDESC 64
+#define SIP_NRXDESC 128
#define SIP_NRXDESC_MASK (SIP_NRXDESC - 1)
#define SIP_NEXTRX(x) (((x) + 1) & SIP_NRXDESC_MASK)
@@ -242,6 +242,16 @@
#define sc_txdescs sc_control_data->scd_txdescs
#define sc_rxdescs sc_control_data->scd_rxdescs
+#ifdef SIP_EVENT_COUNTERS
+ /*
+ * Event counters.
+ */
+ struct evcnt sc_ev_txsstall; /* Tx stalled due to no txs */
+ struct evcnt sc_ev_txdstall; /* Tx stalled due to no txd */
+ struct evcnt sc_ev_txintr; /* Tx interrupts */
+ struct evcnt sc_ev_rxintr; /* Rx interrupts */
+#endif /* SIP_EVENT_COUNTERS */
+
u_int32_t sc_txcfg; /* prototype TXCFG register */
u_int32_t sc_rxcfg; /* prototype RXCFG register */
u_int32_t sc_imr; /* prototype IMR register */
@@ -272,6 +282,12 @@
/* sc_flags */
#define SIPF_PAUSED 0x00000001 /* paused (802.3x flow control) */
+#ifdef SIP_EVENT_COUNTERS
+#define SIP_EVCNT_INCR(ev) (ev)->ev_count++
+#else
+#define SIP_EVCNT_INCR(ev) /* nothing */
+#endif
+
#define SIP_CDTXADDR(sc, x) ((sc)->sc_cddma + SIP_CDTXOFF((x)))
#define SIP_CDRXADDR(sc, x) ((sc)->sc_cddma + SIP_CDRXOFF((x)))
@@ -784,6 +800,20 @@
if_attach(ifp);
ether_ifattach(ifp, enaddr);
+#ifdef SIP_EVENT_COUNTERS
+ /*
+ * Attach event counters.
+ */
+ evcnt_attach_dynamic(&sc->sc_ev_txsstall, EVCNT_TYPE_MISC,
+ NULL, sc->sc_dev.dv_xname, "txsstall");
+ evcnt_attach_dynamic(&sc->sc_ev_txdstall, EVCNT_TYPE_MISC,
+ NULL, sc->sc_dev.dv_xname, "txdstall");
+ evcnt_attach_dynamic(&sc->sc_ev_txintr, EVCNT_TYPE_INTR,
+ NULL, sc->sc_dev.dv_xname, "txintr");
+ evcnt_attach_dynamic(&sc->sc_ev_rxintr, EVCNT_TYPE_INTR,
+ NULL, sc->sc_dev.dv_xname, "rxintr");
+#endif /* SIP_EVENT_COUNTERS */
+
/*
* Make sure the interface is shutdown during reboot.
*/
@@ -869,8 +899,13 @@
* until we drain the queue, or use up all available transmit
* descriptors.
*/
- while ((txs = SIMPLEQ_FIRST(&sc->sc_txfreeq)) != NULL &&
- sc->sc_txfree != 0) {
+ for (;;) {
+ /* Get a work queue entry. */
+ if ((txs = SIMPLEQ_FIRST(&sc->sc_txfreeq)) == NULL) {
+ SIP_EVCNT_INCR(&sc->sc_ev_txsstall);
+ break;
+ }
+
/*
* Grab a packet off the queue.
*/
@@ -917,9 +952,11 @@
/*
* Ensure we have enough descriptors free to describe
- * the packet.
+ * the packet. Note, we always reserve one descriptor
+ * at the end of the ring as a termination point, to
+ * prevent wrap-around.
*/
- if (dmamap->dm_nsegs > sc->sc_txfree) {
+ if (dmamap->dm_nsegs > (sc->sc_txfree - 1)) {
/*
* Not enough free descriptors to transmit this
* packet. We haven't committed anything yet,
@@ -934,6 +971,7 @@
bus_dmamap_unload(sc->sc_dmat, dmamap);
if (m != NULL)
m_freem(m);
+ SIP_EVCNT_INCR(&sc->sc_ev_txdstall);
break;
}
@@ -1041,13 +1079,31 @@
SIP_CDTXSYNC(sc, firsttx, 1,
BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
- /* Start the transmit process. */
+ /*
+ * Start the transmit process. Note, the manual says
+ * that if there are no pending transmissions in the
+ * chip's internal queue (indicated by TXE being clear),
+ * then the driver software must set the TXDP to the
+ * first descriptor to be transmitted. However, if we
+ * do this, it causes serious performance degredation on
+ * the DP83820 under load, not setting TXDP doesn't seem
+ * to adversely affect the SiS 900 or DP83815.
+ *
+ * Well, I guess it wouldn't be the first time a manual
+ * has lied -- and they could be speaking of the NULL-
+ * terminated descriptor list case, rather than OWN-
+ * terminated rings.
+ */
+#if 0
if ((bus_space_read_4(sc->sc_st, sc->sc_sh, SIP_CR) &
CR_TXE) == 0) {
bus_space_write_4(sc->sc_st, sc->sc_sh, SIP_TXDP,
SIP_CDTXADDR(sc, firsttx));
bus_space_write_4(sc->sc_st, sc->sc_sh, SIP_CR, CR_TXE);
}
+#else
+ bus_space_write_4(sc->sc_st, sc->sc_sh, SIP_CR, CR_TXE);
+#endif
/* Set a watchdog timer in case the chip flakes out. */
ifp->if_timer = 5;
@@ -1148,6 +1204,8 @@
handled = 1;
if (isr & (ISR_RXORN|ISR_RXIDLE|ISR_RXDESC)) {
+ SIP_EVCNT_INCR(&sc->sc_ev_rxintr);
+
/* Grab any new packets. */
SIP_DECL(rxintr)(sc);
@@ -1171,6 +1229,8 @@
}
if (isr & (ISR_TXURN|ISR_TXDESC)) {
+ SIP_EVCNT_INCR(&sc->sc_ev_txintr);
+
/* Sweep up transmit descriptors. */
SIP_DECL(txintr)(sc);
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