2 files changed, 14 insertions, 0 deletions

diff --git a/net/core/user_dma.c b/net/core/user_dma.c
index 9eee91bcbf3f..b7c98dbcdb81 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 6b6c3adfcf00..6a6aa537b7aa 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 }
 };