PERFORCE change 73025 for review

[Sam Leffler]

http://perforce.freebsd.org/chv.cgi?CH=73025

Change 73025 by sam at sam_ebb on 2005/03/13 18:35:34

	o check for rdonly mbuf's when coalescing
	o save stats+test stuff since this is a private branch

Affected files ...

.. //depot/projects/wifi/sys/dev/ath/if_ath.c#76 edit

Differences ...

==== //depot/projects/wifi/sys/dev/ath/if_ath.c#76 (text+ko) ====

@@ -3269,6 +3269,18 @@
 			ath_tx_cleanupq(sc, &sc->sc_txq[i]);
 }
 
+SYSCTL_NODE(_hw_ath, OID_AUTO, defrag, CTLFLAG_RD, 0, "defrag testing");
+static int ath_maxfrags = 4;
+SYSCTL_INT(_hw_ath_defrag, OID_AUTO, max, CTLFLAG_RW, &ath_maxfrags, 0, "");
+static int ath_defrags;
+SYSCTL_INT(_hw_ath_defrag, OID_AUTO, calls, CTLFLAG_RW, &ath_defrags, 0, "");
+static int ath_collectedfrags;
+SYSCTL_INT(_hw_ath_defrag, OID_AUTO, combined, CTLFLAG_RW, &ath_collectedfrags, 0, "");
+static int ath_replacedfrags;
+SYSCTL_INT(_hw_ath_defrag, OID_AUTO, replaced, CTLFLAG_RW, &ath_replacedfrags, 0, "");
+static int ath_defragsfail;
+SYSCTL_INT(_hw_ath_defrag, OID_AUTO, fail, CTLFLAG_RW, &ath_defragsfail, 0, "");
+
 /*
  * Defragment an mbuf chain, returning at most maxfrags separate
  * mbufs+clusters.  If this is not possible NULL is returned and
@@ -3282,12 +3294,14 @@
 	struct mbuf *m, *n, *n2, **prev;
 	u_int curfrags;
 
+ath_defrags++;/*XXX*/
 	/*
 	 * Calculate the current number of frags.
 	 */
 	curfrags = 0;
 	for (m = m0; m != NULL; m = m->m_next)
 		curfrags++;
+if (curfrags <= maxfrags) return m0; /* XXX for testing */
 	/*
 	 * First, try to collapse mbufs.  Note that we always collapse
 	 * towards the front so we don't need to deal with moving the
@@ -3300,12 +3314,14 @@
 		n = m->m_next;
 		if (n == NULL)
 			break;
-		if (n->m_len < M_TRAILINGSPACE(m)) {
+		if ((m->m_flags & M_RDONLY) == 0 &&
+		    n->m_len < M_TRAILINGSPACE(m)) {
 			bcopy(mtod(n, void *), mtod(m, char *) + m->m_len,
 				n->m_len);
 			m->m_len += n->m_len;
 			m->m_next = n->m_next;
 			m_free(n);
+ath_collectedfrags++;/*XXX*/
 			if (--curfrags <= maxfrags)
 				return m0;
 		} else
@@ -3331,6 +3347,7 @@
 			*prev = m;
 			m_free(n);
 			m_free(n2);
+ath_replacedfrags++;/*XXX*/
 			if (--curfrags <= maxfrags)	/* +1 cl -2 mbufs */
 				return m0;
 			/*
@@ -3349,6 +3366,7 @@
 	 * packet header).
 	 */
 bad:
+ath_defragsfail++;/*XXX*/
 	return NULL;
 }
 
@@ -3423,6 +3441,8 @@
 
 	pktlen += IEEE80211_CRC_LEN;
 
+m = ath_defrag(m0, M_DONTWAIT, ath_maxfrags); if (m != NULL) m0 = m;	/*XXX*/
+
 	/*
 	 * Load the DMA map so any coalescing is done.  This
 	 * also calculates the number of descriptors we need.