svn commit: r237000 - head/sys/dev/ath

Adrian Chadd adrian at FreeBSD.org
Wed Jun 13 06:57:55 UTC 2012


Author: adrian
Date: Wed Jun 13 06:57:55 2012
New Revision: 237000
URL: http://svn.freebsd.org/changeset/base/237000

Log:
  Implement a separate, smaller pool of ath_buf entries for use by management
  traffic.
  
  * Create sc_mgmt_txbuf and sc_mgmt_txdesc, initialise/free them appropriately.
  * Create an enum to represent buffer types in the API.
  * Extend ath_getbuf() and _ath_getbuf_locked() to take the above enum.
  * Right now anything sent via ic_raw_xmit() allocates via ATH_BUFTYPE_MGMT.
    This may not be very useful.
  * Add ATH_BUF_MGMT flag (ath_buf.bf_flags) which indicates the current buffer
    is a mgmt buffer and should go back onto the mgmt free list.
  * Extend 'txagg' to include debugging output for both normal and mgmt txbufs.
  * When checking/clearing ATH_BUF_BUSY, do it on both TX pools.
  
  Tested:
  
  * STA mode, with heavy UDP injection via iperf.  This filled the TX queue
    however BARs were still going out successfully.
  
  TODO:
  
  * Initialise the mgmt buffers with ATH_BUF_MGMT and then ensure the right
    type is being allocated and freed on the appropriate list.  That'd save
    a write operation (to bf->bf_flags) on each buffer alloc/free.
  
  * Test on AP mode, ensure that BAR TX and probe responses go out nicely
    when the main TX queue is filled (eg with paused traffic to a TID,
    awaiting a BAR to complete.)
  
  PR:		kern/168170

Modified:
  head/sys/dev/ath/if_ath.c
  head/sys/dev/ath/if_ath_misc.h
  head/sys/dev/ath/if_ath_sysctl.c
  head/sys/dev/ath/if_ath_tx.c
  head/sys/dev/ath/if_athvar.h

Modified: head/sys/dev/ath/if_ath.c
==============================================================================
--- head/sys/dev/ath/if_ath.c	Wed Jun 13 06:46:00 2012	(r236999)
+++ head/sys/dev/ath/if_ath.c	Wed Jun 13 06:57:55 2012	(r237000)
@@ -246,6 +246,10 @@ static	int ath_txbuf = ATH_TXBUF;		/* # 
 SYSCTL_INT(_hw_ath, OID_AUTO, txbuf, CTLFLAG_RW, &ath_txbuf,
 	    0, "tx buffers allocated");
 TUNABLE_INT("hw.ath.txbuf", &ath_txbuf);
+static	int ath_txbuf_mgmt = ATH_MGMT_TXBUF;	/* # mgmt tx buffers to allocate */
+SYSCTL_INT(_hw_ath, OID_AUTO, txbuf_mgmt, CTLFLAG_RW, &ath_txbuf_mgmt,
+	    0, "tx (mgmt) buffers allocated");
+TUNABLE_INT("hw.ath.txbuf_mgmt", &ath_txbuf_mgmt);
 
 int ath_bstuck_threshold = 4;		/* max missed beacons */
 SYSCTL_INT(_hw_ath, OID_AUTO, bstuck, CTLFLAG_RW, &ath_bstuck_threshold,
@@ -2212,13 +2216,17 @@ ath_reset_vap(struct ieee80211vap *vap, 
 }
 
 struct ath_buf *
-_ath_getbuf_locked(struct ath_softc *sc)
+_ath_getbuf_locked(struct ath_softc *sc, ath_buf_type_t btype)
 {
 	struct ath_buf *bf;
 
 	ATH_TXBUF_LOCK_ASSERT(sc);
 
-	bf = TAILQ_FIRST(&sc->sc_txbuf);
+	if (btype == ATH_BUFTYPE_MGMT)
+		bf = TAILQ_FIRST(&sc->sc_txbuf_mgmt);
+	else
+		bf = TAILQ_FIRST(&sc->sc_txbuf);
+
 	if (bf == NULL) {
 		sc->sc_stats.ast_tx_getnobuf++;
 	} else {
@@ -2228,18 +2236,29 @@ _ath_getbuf_locked(struct ath_softc *sc)
 		}
 	}
 
-	if (bf != NULL && (bf->bf_flags & ATH_BUF_BUSY) == 0)
-		TAILQ_REMOVE(&sc->sc_txbuf, bf, bf_list);
-	else
+	if (bf != NULL && (bf->bf_flags & ATH_BUF_BUSY) == 0) {
+		if (btype == ATH_BUFTYPE_MGMT)
+			TAILQ_REMOVE(&sc->sc_txbuf_mgmt, bf, bf_list);
+		else
+			TAILQ_REMOVE(&sc->sc_txbuf, bf, bf_list);
+	} else
 		bf = NULL;
 
 	if (bf == NULL) {
+		/* XXX should check which list, mgmt or otherwise */
 		DPRINTF(sc, ATH_DEBUG_XMIT, "%s: %s\n", __func__,
 		    TAILQ_FIRST(&sc->sc_txbuf) == NULL ?
 			"out of xmit buffers" : "xmit buffer busy");
 		return NULL;
 	}
 
+	/* XXX TODO: should do this at buffer list initialisation */
+	/* XXX (then, ensure the buffer has the right flag set) */
+	if (btype == ATH_BUFTYPE_MGMT)
+		bf->bf_flags |= ATH_BUF_MGMT;
+	else
+		bf->bf_flags &= (~ATH_BUF_MGMT);
+
 	/* Valid bf here; clear some basic fields */
 	bf->bf_next = NULL;	/* XXX just to be sure */
 	bf->bf_last = NULL;	/* XXX again, just to be sure */
@@ -2274,7 +2293,9 @@ ath_buf_clone(struct ath_softc *sc, cons
 {
 	struct ath_buf *tbf;
 
-	tbf = ath_getbuf(sc);
+	tbf = ath_getbuf(sc,
+	    (bf->bf_flags & ATH_BUF_MGMT) ?
+	     ATH_BUFTYPE_MGMT : ATH_BUFTYPE_NORMAL);
 	if (tbf == NULL)
 		return NULL;	/* XXX failure? Why? */
 
@@ -2302,12 +2323,18 @@ ath_buf_clone(struct ath_softc *sc, cons
 }
 
 struct ath_buf *
-ath_getbuf(struct ath_softc *sc)
+ath_getbuf(struct ath_softc *sc, ath_buf_type_t btype)
 {
 	struct ath_buf *bf;
 
 	ATH_TXBUF_LOCK(sc);
-	bf = _ath_getbuf_locked(sc);
+	bf = _ath_getbuf_locked(sc, btype);
+	/*
+	 * If a mgmt buffer was requested but we're out of those,
+	 * try requesting a normal one.
+	 */
+	if (bf == NULL && btype == ATH_BUFTYPE_MGMT)
+		bf = _ath_getbuf_locked(sc, ATH_BUFTYPE_NORMAL);
 	ATH_TXBUF_UNLOCK(sc);
 	if (bf == NULL) {
 		struct ifnet *ifp = sc->sc_ifp;
@@ -2351,7 +2378,7 @@ ath_start(struct ifnet *ifp)
 		/*
 		 * Grab a TX buffer and associated resources.
 		 */
-		bf = ath_getbuf(sc);
+		bf = ath_getbuf(sc, ATH_BUFTYPE_NORMAL);
 		if (bf == NULL)
 			break;
 
@@ -2857,11 +2884,26 @@ ath_desc_alloc(struct ath_softc *sc)
 		return error;
 	}
 
+	error = ath_descdma_setup(sc, &sc->sc_txdma_mgmt, &sc->sc_txbuf_mgmt,
+			"tx_mgmt", ath_txbuf_mgmt, ATH_TXDESC);
+	if (error != 0) {
+		ath_descdma_cleanup(sc, &sc->sc_rxdma, &sc->sc_rxbuf);
+		ath_descdma_cleanup(sc, &sc->sc_txdma, &sc->sc_txbuf);
+		return error;
+	}
+
+	/*
+	 * XXX mark txbuf_mgmt frames with ATH_BUF_MGMT, so the
+	 * flag doesn't have to be set in ath_getbuf_locked().
+	 */
+
 	error = ath_descdma_setup(sc, &sc->sc_bdma, &sc->sc_bbuf,
 			"beacon", ATH_BCBUF, 1);
 	if (error != 0) {
-		ath_descdma_cleanup(sc, &sc->sc_txdma, &sc->sc_txbuf);
 		ath_descdma_cleanup(sc, &sc->sc_rxdma, &sc->sc_rxbuf);
+		ath_descdma_cleanup(sc, &sc->sc_txdma, &sc->sc_txbuf);
+		ath_descdma_cleanup(sc, &sc->sc_txdma_mgmt,
+		    &sc->sc_txbuf_mgmt);
 		return error;
 	}
 	return 0;
@@ -2877,6 +2919,9 @@ ath_desc_free(struct ath_softc *sc)
 		ath_descdma_cleanup(sc, &sc->sc_txdma, &sc->sc_txbuf);
 	if (sc->sc_rxdma.dd_desc_len != 0)
 		ath_descdma_cleanup(sc, &sc->sc_rxdma, &sc->sc_rxbuf);
+	if (sc->sc_txdma_mgmt.dd_desc_len != 0)
+		ath_descdma_cleanup(sc, &sc->sc_txdma_mgmt,
+		    &sc->sc_txbuf_mgmt);
 }
 
 static struct ieee80211_node *
@@ -3323,12 +3368,14 @@ ath_tx_update_busy(struct ath_softc *sc)
 	 * descriptor.
 	 */
 	ATH_TXBUF_LOCK_ASSERT(sc);
+	last = TAILQ_LAST(&sc->sc_txbuf_mgmt, ath_bufhead_s);
+	if (last != NULL)
+		last->bf_flags &= ~ATH_BUF_BUSY;
 	last = TAILQ_LAST(&sc->sc_txbuf, ath_bufhead_s);
 	if (last != NULL)
 		last->bf_flags &= ~ATH_BUF_BUSY;
 }
 
-
 /*
  * Process completed xmit descriptors from the specified queue.
  * Kick the packet scheduler if needed. This can occur from this
@@ -3637,7 +3684,10 @@ ath_returnbuf_tail(struct ath_softc *sc,
 
 	ATH_TXBUF_LOCK_ASSERT(sc);
 
-	TAILQ_INSERT_TAIL(&sc->sc_txbuf, bf, bf_list);
+	if (bf->bf_flags & ATH_BUF_MGMT)
+		TAILQ_INSERT_TAIL(&sc->sc_txbuf_mgmt, bf, bf_list);
+	else
+		TAILQ_INSERT_TAIL(&sc->sc_txbuf, bf, bf_list);
 }
 
 void
@@ -3646,7 +3696,10 @@ ath_returnbuf_head(struct ath_softc *sc,
 
 	ATH_TXBUF_LOCK_ASSERT(sc);
 
-	TAILQ_INSERT_HEAD(&sc->sc_txbuf, bf, bf_list);
+	if (bf->bf_flags & ATH_BUF_MGMT)
+		TAILQ_INSERT_HEAD(&sc->sc_txbuf_mgmt, bf, bf_list);
+	else
+		TAILQ_INSERT_HEAD(&sc->sc_txbuf, bf, bf_list);
 }
 
 /*
@@ -3727,6 +3780,9 @@ ath_tx_draintxq(struct ath_softc *sc, st
 	bf = TAILQ_LAST(&sc->sc_txbuf, ath_bufhead_s);
 	if (bf != NULL)
 		bf->bf_flags &= ~ATH_BUF_BUSY;
+	bf = TAILQ_LAST(&sc->sc_txbuf_mgmt, ath_bufhead_s);
+	if (bf != NULL)
+		bf->bf_flags &= ~ATH_BUF_BUSY;
 	ATH_TXBUF_UNLOCK(sc);
 
 	for (ix = 0;; ix++) {

Modified: head/sys/dev/ath/if_ath_misc.h
==============================================================================
--- head/sys/dev/ath/if_ath_misc.h	Wed Jun 13 06:46:00 2012	(r236999)
+++ head/sys/dev/ath/if_ath_misc.h	Wed Jun 13 06:57:55 2012	(r237000)
@@ -50,10 +50,13 @@
 
 extern int ath_tx_findrix(const struct ath_softc *sc, uint8_t rate);
 
-extern struct ath_buf * ath_getbuf(struct ath_softc *sc);
-extern struct ath_buf * _ath_getbuf_locked(struct ath_softc *sc);
+extern struct ath_buf * ath_getbuf(struct ath_softc *sc,
+	    ath_buf_type_t btype);
+extern struct ath_buf * _ath_getbuf_locked(struct ath_softc *sc,
+	    ath_buf_type_t btype);
 extern struct ath_buf * ath_buf_clone(struct ath_softc *sc,
 	    const struct ath_buf *bf);
+/* XXX change this to NULL the buffer pointer? */
 extern void ath_freebuf(struct ath_softc *sc, struct ath_buf *bf);
 extern void ath_returnbuf_head(struct ath_softc *sc, struct ath_buf *bf);
 extern void ath_returnbuf_tail(struct ath_softc *sc, struct ath_buf *bf);

Modified: head/sys/dev/ath/if_ath_sysctl.c
==============================================================================
--- head/sys/dev/ath/if_ath_sysctl.c	Wed Jun 13 06:46:00 2012	(r236999)
+++ head/sys/dev/ath/if_ath_sysctl.c	Wed Jun 13 06:57:55 2012	(r237000)
@@ -377,6 +377,19 @@ ath_sysctl_txagg(SYSCTL_HANDLER_ARGS)
 	printf("Total TX buffers: %d; Total TX buffers busy: %d\n",
 	    t, i);
 
+	i = t = 0;
+	ATH_TXBUF_LOCK(sc);
+	TAILQ_FOREACH(bf, &sc->sc_txbuf_mgmt, bf_list) {
+		if (bf->bf_flags & ATH_BUF_BUSY) {
+			printf("Busy: %d\n", t);
+			i++;
+		}
+		t++;
+	}
+	ATH_TXBUF_UNLOCK(sc);
+	printf("Total mgmt TX buffers: %d; Total mgmt TX buffers busy: %d\n",
+	    t, i);
+
 	return 0;
 }
 

Modified: head/sys/dev/ath/if_ath_tx.c
==============================================================================
--- head/sys/dev/ath/if_ath_tx.c	Wed Jun 13 06:46:00 2012	(r236999)
+++ head/sys/dev/ath/if_ath_tx.c	Wed Jun 13 06:57:55 2012	(r237000)
@@ -203,7 +203,8 @@ ath_txfrag_setup(struct ath_softc *sc, a
 
 	ATH_TXBUF_LOCK(sc);
 	for (m = m0->m_nextpkt; m != NULL; m = m->m_nextpkt) {
-		bf = _ath_getbuf_locked(sc);
+		/* XXX non-management? */
+		bf = _ath_getbuf_locked(sc, ATH_BUFTYPE_NORMAL);
 		if (bf == NULL) {	/* out of buffers, cleanup */
 			device_printf(sc->sc_dev, "%s: no buffer?\n",
 			    __func__);
@@ -1878,7 +1879,7 @@ ath_raw_xmit(struct ieee80211_node *ni, 
 	/*
 	 * Grab a TX buffer and associated resources.
 	 */
-	bf = ath_getbuf(sc);
+	bf = ath_getbuf(sc, ATH_BUFTYPE_MGMT);
 	if (bf == NULL) {
 		sc->sc_stats.ast_tx_nobuf++;
 		m_freem(m);

Modified: head/sys/dev/ath/if_athvar.h
==============================================================================
--- head/sys/dev/ath/if_athvar.h	Wed Jun 13 06:46:00 2012	(r236999)
+++ head/sys/dev/ath/if_athvar.h	Wed Jun 13 06:57:55 2012	(r237000)
@@ -44,6 +44,14 @@
 #define	ATH_TIMEOUT		1000
 
 /*
+ * There is a separate TX ath_buf pool for management frames.
+ * This ensures that management frames such as probe responses
+ * and BAR frames can be transmitted during periods of high
+ * TX activity.
+ */
+#define	ATH_MGMT_TXBUF		32
+
+/*
  * 802.11n requires more TX and RX buffers to do AMPDU.
  */
 #ifdef	ATH_ENABLE_11N
@@ -172,6 +180,11 @@ struct ath_node {
 	((((x)%(mul)) >= ((mul)/2)) ? ((x) + ((mul) - 1)) / (mul) : (x)/(mul))
 #define	ATH_RSSI(x)		ATH_EP_RND(x, HAL_RSSI_EP_MULTIPLIER)
 
+typedef enum {
+	ATH_BUFTYPE_NORMAL	= 0,
+	ATH_BUFTYPE_MGMT	= 1,
+} ath_buf_type_t;
+
 struct ath_buf {
 	TAILQ_ENTRY(ath_buf)	bf_list;
 	struct ath_buf *	bf_next;	/* next buffer in the aggregate */
@@ -243,6 +256,7 @@ struct ath_buf {
 };
 typedef TAILQ_HEAD(ath_bufhead_s, ath_buf) ath_bufhead;
 
+#define	ATH_BUF_MGMT	0x00000001	/* (tx) desc is a mgmt desc */
 #define	ATH_BUF_BUSY	0x00000002	/* (tx) desc owned by h/w */
 
 /*
@@ -487,6 +501,8 @@ struct ath_softc {
 
 	struct ath_descdma	sc_txdma;	/* TX descriptors */
 	ath_bufhead		sc_txbuf;	/* transmit buffer */
+	struct ath_descdma	sc_txdma_mgmt;	/* mgmt TX descriptors */
+	ath_bufhead		sc_txbuf_mgmt;	/* mgmt transmit buffer */
 	struct mtx		sc_txbuflock;	/* txbuf lock */
 	char			sc_txname[12];	/* e.g. "ath0_buf" */
 	u_int			sc_txqsetup;	/* h/w queues setup */


More information about the svn-src-all mailing list