[I/OAT]: Add a sysctl for tuning the I/OAT offloaded I/O threshold
Any socket recv of less than this ammount will not be offloaded
Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 76eaeff..cd9e7c0 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -403,6 +403,7 @@
NET_TCP_MTU_PROBING=113,
NET_TCP_BASE_MSS=114,
NET_IPV4_TCP_WORKAROUND_SIGNED_WINDOWS=115,
+ NET_TCP_DMA_COPYBREAK=116,
};
enum {
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 578cccf..f1f4727 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -219,6 +219,7 @@
extern int sysctl_tcp_tw_reuse;
extern int sysctl_tcp_frto;
extern int sysctl_tcp_low_latency;
+extern int sysctl_tcp_dma_copybreak;
extern int sysctl_tcp_nometrics_save;
extern int sysctl_tcp_moderate_rcvbuf;
extern int sysctl_tcp_tso_win_divisor;
diff --git a/net/core/user_dma.c b/net/core/user_dma.c
index 9eee91b..b7c98db 100644
--- a/net/core/user_dma.c
+++ b/net/core/user_dma.c
@@ -30,6 +30,10 @@
#include <linux/rtnetlink.h> /* for BUG_TRAP */
#include <net/tcp.h>
+#define NET_DMA_DEFAULT_COPYBREAK 4096
+
+int sysctl_tcp_dma_copybreak = NET_DMA_DEFAULT_COPYBREAK;
+
/**
* dma_skb_copy_datagram_iovec - Copy a datagram to an iovec.
* @skb - buffer to copy
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 6b6c3ad..6a6aa53 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -688,6 +688,16 @@
.mode = 0644,
.proc_handler = &proc_dointvec
},
+#ifdef CONFIG_NET_DMA
+ {
+ .ctl_name = NET_TCP_DMA_COPYBREAK,
+ .procname = "tcp_dma_copybreak",
+ .data = &sysctl_tcp_dma_copybreak,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec
+ },
+#endif
{ .ctl_name = 0 }
};