Author: glebius
Date: Sat Mar 22 18:24:44 2014
New Revision: 263649
URL: http://svnweb.freebsd.org/changeset/base/263649
Log:
sfxge: limit software Tx queue size.
Previous implementation limits put queue size only (when Tx lock can't
be acquired), but get queue may grow unboundedly which results in mbuf
pools exhaustion and latency growth.
Submitted by: Andrew Rybchenko <Andrew.Rybchenko at oktetlabs.ru>
Sponsored by: Solarflare Communications, Inc.
Modified:
head/sys/dev/sfxge/sfxge_tx.c
head/sys/dev/sfxge/sfxge_tx.h
Modified: head/sys/dev/sfxge/sfxge_tx.c
==============================================================================
--- head/sys/dev/sfxge/sfxge_tx.c Sat Mar 22 17:28:14 2014
(r263648)
+++ head/sys/dev/sfxge/sfxge_tx.c Sat Mar 22 18:24:44 2014
(r263649)
@@ -461,6 +461,9 @@ sfxge_tx_qdpl_put(struct sfxge_txq *txq,
sfxge_tx_qdpl_swizzle(txq);
+ if (stdp->std_count >= SFXGE_TX_DPL_GET_PKT_LIMIT_DEFAULT)
+ return (ENOBUFS);
+
*(stdp->std_getp) = mbuf;
stdp->std_getp = &mbuf->m_nextpkt;
stdp->std_count++;
@@ -480,8 +483,8 @@ sfxge_tx_qdpl_put(struct sfxge_txq *txq,
old_len = mp->m_pkthdr.csum_data;
} else
old_len = 0;
- if (old_len >= SFXGE_TX_MAX_DEFERRED)
- return ENOBUFS;
+ if (old_len >= SFXGE_TX_DPL_PUT_PKT_LIMIT_DEFAULT)
+ return (ENOBUFS);
mbuf->m_pkthdr.csum_data = old_len + 1;
mbuf->m_nextpkt = (void *)old;
} while (atomic_cmpset_ptr(putp, old, new) == 0);
@@ -512,12 +515,9 @@ sfxge_tx_packet_add(struct sfxge_txq *tx
*/
locked = mtx_trylock(&txq->lock);
- /*
- * Can only fail if we weren't able to get the lock.
- */
if (sfxge_tx_qdpl_put(txq, m, locked) != 0) {
- KASSERT(!locked,
- ("sfxge_tx_qdpl_put() failed locked"));
+ if (locked)
+ mtx_unlock(&txq->lock);
rc = ENOBUFS;
goto fail;
}
Modified: head/sys/dev/sfxge/sfxge_tx.h
==============================================================================
--- head/sys/dev/sfxge/sfxge_tx.h Sat Mar 22 17:28:14 2014
(r263648)
+++ head/sys/dev/sfxge/sfxge_tx.h Sat Mar 22 18:24:44 2014
(r263649)
@@ -75,7 +75,8 @@ struct sfxge_tx_mapping {
enum sfxge_tx_buf_flags flags;
};
-#define SFXGE_TX_MAX_DEFERRED 64
+#define SFXGE_TX_DPL_GET_PKT_LIMIT_DEFAULT 64
+#define SFXGE_TX_DPL_PUT_PKT_LIMIT_DEFAULT 64
/*
* Deferred packet list.
_______________________________________________
[email protected] mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "[email protected]"
