From 9593782585e0cf70babe787a8463d492a68b1744 Mon Sep 17 00:00:00 2001
From: Chris Leech <christopher.leech@intel.com>
Date: Tue, 23 May 2006 18:02:55 -0700
Subject: [PATCH] [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>
---
include/linux/sysctl.h | 1 +
include/net/tcp.h | 1 +
net/core/user_dma.c | 4 ++++
net/ipv4/sysctl_net_ipv4.c | 10 ++++++++++
4 files changed, 16 insertions(+)
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 76eaeff76f8..cd9e7c0825a 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -403,6 +403,7 @@ enum
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 578cccf275d..f1f472746e6 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -219,6 +219,7 @@ extern int sysctl_tcp_adv_win_scale;
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 9eee91bcbf3..b7c98dbcdb8 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 6b6c3adfcf0..6a6aa537b7a 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -688,6 +688,16 @@ ctl_table ipv4_table[] = {
.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 }
};
--
2.41.3