svn commit: r280160 - in head: share/man/man4 sys/dev/sfxge
Andrew Rybchenko
arybchik at FreeBSD.org
Tue Mar 17 08:14:48 UTC 2015
Author: arybchik
Date: Tue Mar 17 08:14:46 2015
New Revision: 280160
URL: https://svnweb.freebsd.org/changeset/base/280160
Log:
sfxge: add tunables to control LRO parameters on driver load time
Sponsored by: Solarflare Communications, Inc.
Approved by: gnn (mentor)
Modified:
head/share/man/man4/sfxge.4
head/sys/dev/sfxge/sfxge_rx.c
Modified: head/share/man/man4/sfxge.4
==============================================================================
--- head/share/man/man4/sfxge.4 Tue Mar 17 05:48:45 2015 (r280159)
+++ head/share/man/man4/sfxge.4 Tue Mar 17 08:14:46 2015 (r280160)
@@ -120,6 +120,27 @@ The value must be greater than or equal
The maximum number of allocated RSS channels for the Nth adapter.
If set to 0 or unset, the number of channels is determined by the number
of CPU cores.
+.It Va hw.sfxge.lro.table_size
+Size of the LRO hash table.
+Must be a power of 2.
+A larger table means we can accelerate a larger number of streams.
+.It Va hw.sfxge.lro.chain_max
+The maximum length of a hash chain.
+If chains get too long then the lookup time increases and may exceed
+the benefit of LRO.
+.It Va hw.sfxge.lro.idle_ticks
+The maximum time (in ticks) that a connection can be idle before it's LRO
+state is discarded.
+.It Va hw.sfxge.lro.slow_start_packets
+Number of packets with payload that must arrive in-order before a connection
+is eligible for LRO.
+The idea is we should avoid coalescing segments when the sender is in
+slow-start because reducing the ACK rate can damage performance.
+.It Va hw.sfxge.lro.loss_packets
+Number of packets with payload that must arrive in-order following loss
+before a connection is eligible for LRO.
+The idea is we should avoid coalescing segments when the sender is recovering
+from loss, because reducing the ACK rate can damage performance.
.El
.Sh SUPPORT
For general information and support,
Modified: head/sys/dev/sfxge/sfxge_rx.c
==============================================================================
--- head/sys/dev/sfxge/sfxge_rx.c Tue Mar 17 05:48:45 2015 (r280159)
+++ head/sys/dev/sfxge/sfxge_rx.c Tue Mar 17 08:14:46 2015 (r280160)
@@ -36,6 +36,7 @@ __FBSDID("$FreeBSD$");
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/limits.h>
+#include <sys/syslog.h>
#include <net/ethernet.h>
#include <net/if.h>
@@ -58,20 +59,38 @@ __FBSDID("$FreeBSD$");
#ifdef SFXGE_LRO
+SYSCTL_NODE(_hw_sfxge, OID_AUTO, lro, CTLFLAG_RD, NULL,
+ "Large receive offload (LRO) parameters");
+
+#define SFXGE_LRO_PARAM(_param) SFXGE_PARAM(lro._param)
+
/* Size of the LRO hash table. Must be a power of 2. A larger table
* means we can accelerate a larger number of streams.
*/
static unsigned lro_table_size = 128;
+TUNABLE_INT(SFXGE_LRO_PARAM(table_size), &lro_table_size);
+SYSCTL_UINT(_hw_sfxge_lro, OID_AUTO, table_size, CTLFLAG_RDTUN,
+ &lro_table_size, 0,
+ "Size of the LRO hash table (must be a power of 2)");
/* Maximum length of a hash chain. If chains get too long then the lookup
* time increases and may exceed the benefit of LRO.
*/
static unsigned lro_chain_max = 20;
+TUNABLE_INT(SFXGE_LRO_PARAM(chain_max), &lro_chain_max);
+SYSCTL_UINT(_hw_sfxge_lro, OID_AUTO, chain_max, CTLFLAG_RDTUN,
+ &lro_chain_max, 0,
+ "The maximum length of a hash chain");
/* Maximum time (in ticks) that a connection can be idle before it's LRO
* state is discarded.
*/
static unsigned lro_idle_ticks; /* initialised in sfxge_rx_init() */
+TUNABLE_INT(SFXGE_LRO_PARAM(idle_ticks), &lro_idle_ticks);
+SYSCTL_UINT(_hw_sfxge_lro, OID_AUTO, idle_ticks, CTLFLAG_RDTUN,
+ &lro_idle_ticks, 0,
+ "The maximum time (in ticks) that a connection can be idle "
+ "before it's LRO state is discarded");
/* Number of packets with payload that must arrive in-order before a
* connection is eligible for LRO. The idea is we should avoid coalescing
@@ -79,6 +98,11 @@ static unsigned lro_idle_ticks; /* initi
* can damage performance.
*/
static int lro_slow_start_packets = 2000;
+TUNABLE_INT(SFXGE_LRO_PARAM(slow_start_packets), &lro_slow_start_packets);
+SYSCTL_UINT(_hw_sfxge_lro, OID_AUTO, slow_start_packets, CTLFLAG_RDTUN,
+ &lro_slow_start_packets, 0,
+ "Number of packets with payload that must arrive in-order before "
+ "a connection is eligible for LRO");
/* Number of packets with payload that must arrive in-order following loss
* before a connection is eligible for LRO. The idea is we should avoid
@@ -86,6 +110,11 @@ static int lro_slow_start_packets = 2000
* reducing the ACK rate can damage performance.
*/
static int lro_loss_packets = 20;
+TUNABLE_INT(SFXGE_LRO_PARAM(loss_packets), &lro_loss_packets);
+SYSCTL_UINT(_hw_sfxge_lro, OID_AUTO, loss_packets, CTLFLAG_RDTUN,
+ &lro_loss_packets, 0,
+ "Number of packets with payload that must arrive in-order "
+ "following loss before a connection is eligible for LRO");
/* Flags for sfxge_lro_conn::l2_id; must not collide with EVL_VLID_MASK */
#define SFXGE_LRO_L2_ID_VLAN 0x4000
@@ -1239,6 +1268,13 @@ sfxge_rx_init(struct sfxge_softc *sc)
int rc;
#ifdef SFXGE_LRO
+ if (!ISP2(lro_table_size)) {
+ log(LOG_ERR, "%s=%u must be power of 2",
+ SFXGE_LRO_PARAM(table_size), lro_table_size);
+ rc = EINVAL;
+ goto fail_lro_table_size;
+ }
+
if (lro_idle_ticks == 0)
lro_idle_ticks = hz / 10 + 1; /* 100 ms */
#endif
@@ -1266,5 +1302,9 @@ fail:
sfxge_rx_qfini(sc, index);
sc->rxq_count = 0;
+
+#ifdef SFXGE_LRO
+fail_lro_table_size:
+#endif
return (rc);
}
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