Project : madwifi
Revision : 2373
Author : scottr (Scott Raynel)
Date : 2007-05-25 04:38:02 +0200 (Fri, 25 May 2007)
Log Message :
Don't call the HAL gettsf64 function so often.
After profiling the driver to diagnose poor performance on
low-end systems (such as the Soekris 4526) it was found that
a large amount of time was being spent in ath_hal_gettsf64().
This was being caused by MadWiFi calling the function multiple
times unnecessarily, for example, for each transmitted packet.
This patch attempts to optimise the number of times we call
into ath_hal_gettsf64(), which reduces the number of PCI register
operations considerably and leads to a noticable performance
increase on low-end systems.
Affected Files:
* trunk/ath/if_ath.c updated
* trunk/ath/if_athvar.h updated
Modified: trunk/ath/if_ath.c
===================================================================
--- trunk/ath/if_ath.c 2007-05-24 23:39:12 UTC (rev 2372)
+++ trunk/ath/if_ath.c 2007-05-25 02:38:02 UTC (rev 2373)
@@ -1334,7 +1334,6 @@
int ac, retval;
u_int8_t tid;
u_int16_t frame_seq;
- u_int64_t tsf;
#define PA2DESC(_sc, _pa) \
((struct ath_desc *)((caddr_t)(_sc)->sc_rxdma.dd_desc + \
((_pa) - (_sc)->sc_rxdma.dd_desc_paddr)))
@@ -1343,7 +1342,6 @@
* based on ic->ic_uapsdmaxtriggers.
*/
- tsf = ath_hal_gettsf64(ah);
ATH_RXBUF_LOCK(sc);
if (sc->sc_rxbufcur == NULL)
sc->sc_rxbufcur = STAILQ_FIRST(&sc->sc_rxbuf);
@@ -1390,7 +1388,7 @@
* a self-linked list to avoid rx overruns.
*/
rs = &bf->bf_dsstatus.ds_rxstat;
- retval = ath_hal_rxprocdesc(ah, ds, bf->bf_daddr, PA2DESC(sc,
ds->ds_link), tsf, rs);
+ retval = ath_hal_rxprocdesc(ah, ds, bf->bf_daddr, PA2DESC(sc,
ds->ds_link), sc->sc_tsf, rs);
if (HAL_EINPROGRESS == retval)
break;
@@ -1668,6 +1666,7 @@
ath_hal_updatetxtriglevel(ah, AH_TRUE);
}
if (status & HAL_INT_RX) {
+ sc->sc_tsf = ath_hal_gettsf64(ah);
ath_uapsd_processtriggers(sc);
ATH_SCHEDULE_TQUEUE(&sc->sc_rxtq, &needmark);
}
@@ -5251,11 +5250,8 @@
* a full 64-bit TSF using the current h/w TSF.
*/
static __inline u_int64_t
-ath_extend_tsf(struct ath_hal *ah, u_int32_t rstamp)
+ath_extend_tsf(u_int64_t tsf, u_int32_t rstamp)
{
- u_int64_t tsf;
-
- tsf = ath_hal_gettsf64(ah);
if ((tsf & 0x7fff) < rstamp)
tsf -= 0x8000;
return ((tsf &~ 0x7fff) | rstamp);
@@ -5272,7 +5268,6 @@
const struct ath_rx_status *rs = &bf->bf_dsstatus.ds_rxstat;
struct ieee80211com *ic = &sc->sc_ic;
struct ieee80211_frame *wh;
- u_int64_t tsf;
/* Pass up tsf clock in mactime
* Rx descriptor has the low 15 bits of the tsf at
@@ -5280,7 +5275,7 @@
* tsf to extend this to 64 bits.
*/
/* NB: Not all chipsets return the same precision rstamp */
- tsf = ath_extend_tsf(sc->sc_ah, rs->rs_tstamp);
+ u_int64_t tsf = ath_extend_tsf(sc->sc_tsf, rs->rs_tstamp);
KASSERT(ic->ic_flags & IEEE80211_F_DATAPAD,
("data padding not enabled?"));
@@ -5304,7 +5299,8 @@
static void
-ath_tx_capture(struct net_device *dev, const struct ath_buf *bf, struct
sk_buff *skb)
+ath_tx_capture(struct net_device *dev, const struct ath_buf *bf, struct
sk_buff *skb,
+ u_int64_t tsf)
{
struct ath_softc *sc = dev->priv;
const struct ath_tx_status *ts = &bf->bf_dsstatus.ds_txstat;
@@ -5312,20 +5308,7 @@
struct ieee80211_frame *wh;
unsigned int extra = A_MAX(sizeof(struct ath_tx_radiotap_header),
A_MAX(sizeof(wlan_ng_prism2_header),
ATHDESC_HEADER_SIZE));
- u_int64_t tsf;
u_int32_t tstamp;
-
- /* Pass up tsf clock in mactime
- * TX descriptor contains the transmit time in TU's,
- * (bits 25-10 of the TSF).
- */
- tsf = ath_hal_gettsf64(sc->sc_ah);
- tstamp = ts->ts_tstamp << 10;
-
- if ((tsf & 0x3ffffff) < tstamp)
- tsf -= 0x4000000;
- tsf = ((tsf &~ 0x3ffffff) | tstamp);
-
/*
* release the owner of this skb since we're basically
* recycling it
@@ -5359,7 +5342,20 @@
printk("%s:%d %s\n", __FILE__, __LINE__, __func__);
goto done;
}
- ieee80211_input_monitor(ic, skb, bf, 1, tsf, sc);
+
+ if (sc->sc_nmonvaps > 0) {
+ /* Pass up tsf clock in mactime
+ * TX descriptor contains the transmit time in TU's,
+ * (bits 25-10 of the TSF).
+ */
+ tstamp = ts->ts_tstamp << 10;
+
+ if ((tsf & 0x3ffffff) < tstamp)
+ tsf -= 0x4000000;
+ tsf = ((tsf &~ 0x3ffffff) | tstamp);
+
+ ieee80211_input_monitor(ic, skb, bf, 1, tsf, sc);
+ }
done:
dev_kfree_skb(skb);
}
@@ -5396,7 +5392,7 @@
case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
if (vap->iv_opmode == IEEE80211_M_IBSS &&
vap->iv_state == IEEE80211_S_RUN) {
- u_int64_t tsf = ath_extend_tsf(sc->sc_ah, rstamp);
+ u_int64_t tsf = ath_extend_tsf(sc->sc_tsf, rstamp);
/*
* Handle ibss merge as needed; check the tsf on the
* frame before attempting the merge. The 802.11 spec
@@ -7118,11 +7114,15 @@
HAL_STATUS status;
int uapsdq = 0;
unsigned long uapsdq_lockflags = 0;
-
+ u_int64_t tsf = 0; /* Only needed for monitor mode */
+
DPRINTF(sc, ATH_DEBUG_TX_PROC, "%s: tx queue %d (0x%x), link %p\n",
__func__,
txq->axq_qnum, ath_hal_gettxbuf(sc->sc_ah, txq->axq_qnum),
txq->axq_link);
+ if (sc->sc_nmonvaps > 0)
+ tsf = ath_hal_gettsf64(ah);
+
if (txq == sc->sc_uapsdq) {
DPRINTF(sc, ATH_DEBUG_UAPSD, "%s: reaping U-APSD txq\n",
__func__);
uapsdq = 1;
@@ -7271,8 +7271,8 @@
}
DPRINTF(sc, ATH_DEBUG_TX_PROC, "%s: free skb %p\n", __func__,
bf->bf_skb);
- ath_tx_capture(sc->sc_dev, bf, bf->bf_skb);
+ ath_tx_capture(sc->sc_dev, bf, bf->bf_skb, tsf);
#ifdef ATH_SUPERG_FF
{
/* Handle every skb after the first one - these are FF
extra
@@ -7286,13 +7286,13 @@
skb->len, BUS_DMA_TODEVICE);
DPRINTF(sc, ATH_DEBUG_TX_PROC, "%s: free skb
%p\n",
__func__, skb);
- ath_tx_capture(sc->sc_dev, bf, skb);
+ ath_tx_capture(sc->sc_dev, bf, skb, tsf);
skb = tskb;
}
}
bf->bf_numdescff = 0;
#endif
-
+
bf->bf_skb = NULL;
bf->bf_node = NULL;
Modified: trunk/ath/if_athvar.h
===================================================================
--- trunk/ath/if_athvar.h 2007-05-24 23:39:12 UTC (rev 2372)
+++ trunk/ath/if_athvar.h 2007-05-25 02:38:02 UTC (rev 2373)
@@ -684,6 +684,7 @@
#endif
u_int sc_slottimeconf; /* manual override for slottime
*/
int16_t sc_channoise; /* Measured noise of current
channel (dBm) */
+ u_int64_t sc_tsf; /* TSF at last rx interrupt */
};
typedef void (*ath_callback) (struct ath_softc *);
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