4. Rebuild sysctl(8)
# cd /usr/src/sbin/sysctl && make && make install
5. Reboot
6. Enable the feature
# sysctl net.inet.tcp.large_recv_offload=1
# ifconfig ix0 down && ifconfig ix0 up
I tested this diff for a while in different scenarios (receiving,
routing, relaying) without noticing any problems yet.
bluhm@ already suggested that I could change the feature switch from a
global sysctl(2) to an per interface ifconfig(8) option. This would
give the user more control.
Tests with other ix(4) NICs are welcome and needed!
bye,
Jan
Index: dev/pci/if_ix.c
===================================================================
RCS file: /cvs/src/sys/dev/pci/if_ix.c,v
retrieving revision 1.185
diff -u -p -r1.185 if_ix.c
--- dev/pci/if_ix.c 15 Mar 2022 11:22:10 -0000 1.185
+++ dev/pci/if_ix.c 23 May 2022 14:39:45 -0000
@@ -2870,7 +2870,7 @@ ixgbe_initialize_receive_units(struct ix
{
struct rx_ring *rxr = sc->rx_rings;
struct ixgbe_hw *hw = &sc->hw;
- uint32_t bufsz, fctrl, srrctl, rxcsum;
+ uint32_t bufsz, fctrl, srrctl, rxcsum, rdrxctl;
uint32_t hlreg;
int i;
@@ -2894,6 +2894,14 @@ ixgbe_initialize_receive_units(struct ix
hlreg |= IXGBE_HLREG0_JUMBOEN;
IXGBE_WRITE_REG(hw, IXGBE_HLREG0, hlreg);
+ if (tcp_lro) {
+ /* enable RSCACKC for RSC */
+ rdrxctl = IXGBE_READ_REG(hw, IXGBE_RDRXCTL);
+ rdrxctl |= IXGBE_RDRXCTL_RSCACKC;
+ rdrxctl |= IXGBE_RDRXCTL_FCOE_WRFIX;
+ IXGBE_WRITE_REG(hw, IXGBE_RDRXCTL, rdrxctl);
+ }
+
bufsz = (sc->rx_mbuf_sz - ETHER_ALIGN) >> IXGBE_SRRCTL_BSIZEPKT_SHIFT;
for (i = 0; i < sc->num_queues; i++, rxr++) {
@@ -2909,6 +2917,12 @@ ixgbe_initialize_receive_units(struct ix
/* Set up the SRRCTL register */
srrctl = bufsz | IXGBE_SRRCTL_DESCTYPE_ADV_ONEBUF;
IXGBE_WRITE_REG(hw, IXGBE_SRRCTL(i), srrctl);
+
+ if (tcp_lro) {
+ /* Enable Receive Side Coalescing */
+ IXGBE_WRITE_REG(hw, IXGBE_RSCCTL(i),
+ IXGBE_RSCCTL_RSCEN|IXGBE_RSCCTL_MAXDESC_16);
+ }
/* Setup the HW Rx Head and Tail Descriptor Pointers */
IXGBE_WRITE_REG(hw, IXGBE_RDH(i), 0);
Index: dev/pci/ixgbe.h
===================================================================
RCS file: /cvs/src/sys/dev/pci/ixgbe.h,v
retrieving revision 1.33
diff -u -p -r1.33 ixgbe.h
--- dev/pci/ixgbe.h 8 Feb 2022 03:38:00 -0000 1.33
+++ dev/pci/ixgbe.h 23 May 2022 14:53:59 -0000
@@ -61,11 +61,16 @@
#include <net/if.h>
#include <net/if_media.h>
#include <net/toeplitz.h>
+#include <net/route.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <netinet/ip.h>
+#include <netinet/ip_ipsp.h>
#include <netinet/ip6.h>
+#include <netinet/tcp.h>
+#include <netinet/tcp_timer.h>
+#include <netinet/tcp_var.h>
#if NBPFILTER > 0
#include <net/bpf.h>
Index: netinet/tcp_input.c
===================================================================
RCS file: /cvs/src/sys/netinet/tcp_input.c,v
retrieving revision 1.375
diff -u -p -r1.375 tcp_input.c
--- netinet/tcp_input.c 4 Jan 2022 06:32:39 -0000 1.375
+++ netinet/tcp_input.c 23 May 2022 14:41:59 -0000
@@ -126,6 +126,7 @@ struct timeval tcp_rst_ppslim_last;
int tcp_ackdrop_ppslim = 100; /* 100pps */
int tcp_ackdrop_ppslim_count = 0;
struct timeval tcp_ackdrop_ppslim_last;
+int tcp_lro = 0; /* TCP Large Receive Offload */
#define TCP_PAWS_IDLE (24 * 24 * 60 * 60 * PR_SLOWHZ)
Index: netinet/tcp_usrreq.c
===================================================================
RCS file: /cvs/src/sys/netinet/tcp_usrreq.c,v
retrieving revision 1.183
diff -u -p -r1.183 tcp_usrreq.c
--- netinet/tcp_usrreq.c 25 Feb 2022 23:51:03 -0000 1.183
+++ netinet/tcp_usrreq.c 23 May 2022 14:43:41 -0000
@@ -128,6 +128,7 @@ const struct sysctl_bounded_args tcpctl_
{ TCPCTL_SYN_BUCKET_LIMIT, &tcp_syn_bucket_limit, 1, INT_MAX },
{ TCPCTL_RFC3390, &tcp_do_rfc3390, 0, 2 },
{ TCPCTL_ALWAYS_KEEPALIVE, &tcp_always_keepalive, 0, 1 },
+ { TCPCTL_LRO, &tcp_lro, 0, 1 },
};
struct inpcbtable tcbtable;
Index: netinet/tcp_var.h
===================================================================
RCS file: /cvs/src/sys/netinet/tcp_var.h,v
retrieving revision 1.139
diff -u -p -r1.139 tcp_var.h
--- netinet/tcp_var.h 25 Feb 2022 23:51:03 -0000 1.139
+++ netinet/tcp_var.h 23 May 2022 14:47:49 -0000
@@ -465,7 +465,8 @@ struct tcpstat {
#define TCPCTL_SYN_USE_LIMIT 23 /* number of uses before reseeding
hash */
#define TCPCTL_ROOTONLY 24 /* return root only port bitmap */
#define TCPCTL_SYN_HASH_SIZE 25 /* number of buckets in the hash */
-#define TCPCTL_MAXID 26
+#define TCPCTL_LRO 26 /* en/disable TCP Large Receive
Offloading */
+#define TCPCTL_MAXID 27
#define TCPCTL_NAMES { \
{ 0, 0 }, \
@@ -494,6 +495,7 @@ struct tcpstat {
{ "synuselimit", CTLTYPE_INT }, \
{ "rootonly", CTLTYPE_STRUCT }, \
{ "synhashsize", CTLTYPE_INT }, \
+ { "large_recv_offload", CTLTYPE_INT }, \
}
struct tcp_ident_mapping {
@@ -652,6 +654,7 @@ extern int tcp_syn_bucket_limit;/* max e
extern int tcp_syn_use_limit; /* number of uses before reseeding hash */
extern struct syn_cache_set tcp_syn_cache[];
extern int tcp_syn_cache_active; /* active syn cache, may be 0 or 1 */
+extern int tcp_lro; /* en/disable large receive offloading */
void tcp_canceltimers(struct tcpcb *);
struct tcpcb *
