diff options
| author | John Fastabend <john.fastabend@gmail.com> | 2018-03-18 22:57:00 +0300 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2018-03-19 23:14:38 +0300 |
| commit | 312fc2b4c82e96a48cb2d0da2bd4816eb253c499 (patch) | |
| tree | 6bcfadb456706b7e326c46f17bff214e56181fcc | |
| parent | ffa35660017161524b7db79b0ce293fa1af16c4d (diff) | |
| download | linux-312fc2b4c82e96a48cb2d0da2bd4816eb253c499.tar.xz | |
net: do_tcp_sendpages flag to avoid SKBTX_SHARED_FRAG
When calling do_tcp_sendpages() from in kernel and we know the data
has no references from user side we can omit SKBTX_SHARED_FRAG flag.
This patch adds an internal flag, NO_SKBTX_SHARED_FRAG that can be used
to omit setting SKBTX_SHARED_FRAG.
The flag is not exposed to userspace because the sendpage call from
the splice logic masks out all bits except MSG_MORE.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| -rw-r--r-- | include/linux/socket.h | 1 | ||||
| -rw-r--r-- | net/ipv4/tcp.c | 4 |
2 files changed, 4 insertions, 1 deletions
diff --git a/include/linux/socket.h b/include/linux/socket.h index 1ce1f768a58c..60e01482a9c4 100644 --- a/include/linux/socket.h +++ b/include/linux/socket.h @@ -287,6 +287,7 @@ struct ucred { #define MSG_SENDPAGE_NOTLAST 0x20000 /* sendpage() internal : not the last page */ #define MSG_BATCH 0x40000 /* sendmmsg(): more messages coming */ #define MSG_EOF MSG_FIN +#define MSG_NO_SHARED_FRAGS 0x80000 /* sendpage() internal : page frags are not shared */ #define MSG_ZEROCOPY 0x4000000 /* Use user data in kernel path */ #define MSG_FASTOPEN 0x20000000 /* Send data in TCP SYN */ diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index fb350f740f69..f90ec24c2cc8 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -994,7 +994,9 @@ new_segment: get_page(page); skb_fill_page_desc(skb, i, page, offset, copy); } - skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; + + if (!(flags & MSG_NO_SHARED_FRAGS)) + skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; skb->len += copy; skb->data_len += copy; |