| Message ID | 1440545634-3901299-3-git-send-email-brakmo@fb.com |
|---|---|
| State | RFC, archived |
| Delegated to: | David Miller |
| Headers | show |
On Tue, Aug 25, 2015 at 4:33 PM, Lawrence Brakmo <brakmo@fb.com> wrote: > > Refactor tcp_skb_cb to create two overlaping areas to store > state for incoming or outgoing skbs based on comments by > Neal Cardwell to tcp_nv patch: > > AFAICT this patch would not require an increase in the size of > sk_buff cb[] if it were to take advantage of the fact that the > tcp_skb_cb header.h4 and header.h6 fields are only used in the packet > reception code path, and this in_flight field is only used on the > transmit side. > > Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Acked-by: Yuchung Cheng <ycheng@google.com> > --- > include/net/tcp.h | 11 ++++++++--- > 1 file changed, 8 insertions(+), 3 deletions(-) > > diff --git a/include/net/tcp.h b/include/net/tcp.h > index 0121529..a086a98 100644 > --- a/include/net/tcp.h > +++ b/include/net/tcp.h > @@ -755,11 +755,16 @@ struct tcp_skb_cb { > /* 1 byte hole */ > __u32 ack_seq; /* Sequence number ACK'd */ > union { > - struct inet_skb_parm h4; > + struct { > + /* There is space for up to 20 bytes */ > + } tx; /* only used for outgoing skbs */ > + union { > + struct inet_skb_parm h4; > #if IS_ENABLED(CONFIG_IPV6) > - struct inet6_skb_parm h6; > + struct inet6_skb_parm h6; > #endif > - } header; /* For incoming frames */ > + } header; /* For incoming skbs */ > + }; > }; > > #define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0])) > -- > 1.8.1 > -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/net/tcp.h b/include/net/tcp.h index 0121529..a086a98 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -755,11 +755,16 @@ struct tcp_skb_cb { /* 1 byte hole */ __u32 ack_seq; /* Sequence number ACK'd */ union { - struct inet_skb_parm h4; + struct { + /* There is space for up to 20 bytes */ + } tx; /* only used for outgoing skbs */ + union { + struct inet_skb_parm h4; #if IS_ENABLED(CONFIG_IPV6) - struct inet6_skb_parm h6; + struct inet6_skb_parm h6; #endif - } header; /* For incoming frames */ + } header; /* For incoming skbs */ + }; }; #define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0]))
Refactor tcp_skb_cb to create two overlaping areas to store state for incoming or outgoing skbs based on comments by Neal Cardwell to tcp_nv patch: AFAICT this patch would not require an increase in the size of sk_buff cb[] if it were to take advantage of the fact that the tcp_skb_cb header.h4 and header.h6 fields are only used in the packet reception code path, and this in_flight field is only used on the transmit side. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> --- include/net/tcp.h | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)