| Message ID | 20180312192319.8039.61347.stgit@john-Precision-Tower-5810 |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | bpf,sockmap: sendmsg/sendfile ULP | expand |
From: John Fastabend <john.fastabend@gmail.com> Date: Mon, 12 Mar 2018 12:23:19 -0700 > 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>
diff --git a/include/linux/socket.h b/include/linux/socket.h index 1ce1f76..60e0148 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 a335397..ff8a8d3 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -994,7 +994,9 @@ ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset, 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;
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> --- include/linux/socket.h | 1 + net/ipv4/tcp.c | 4 +++- 2 files changed, 4 insertions(+), 1 deletion(-)