path: root/include/linux
diff options
authorDavid S. Miller <davem@davemloft.net>2005-07-05 15:24:38 -0700
committerDavid S. Miller <davem@davemloft.net>2005-07-05 15:24:38 -0700
commitc1b4a7e69576d65efc31a8cea0714173c2841244 (patch)
tree92082532651cddc6f0649a9d7ca9ca63e381d310 /include/linux
parent0d9901df62fe4820aee86b49f1a074cdb5c6928e (diff)
[TCP]: Move to new TSO segmenting scheme.
Make TSO segment transmit size decisions at send time not earlier. The basic scheme is that we try to build as large a TSO frame as possible when pulling in the user data, but the size of the TSO frame output to the card is determined at transmit time. This is guided by tp->xmit_size_goal. It is always set to a multiple of MSS and tells sendmsg/sendpage how large an SKB to try and build. Later, tcp_write_xmit() and tcp_push_one() chop up the packet if necessary and conditions warrant. These routines can also decide to "defer" in order to wait for more ACKs to arrive and thus allow larger TSO frames to be emitted. A general observation is that TSO elongates the pipe, thus requiring a larger congestion window and larger buffering especially at the sender side. Therefore, it is important that applications 1) get a large enough socket send buffer (this is accomplished by our dynamic send buffer expansion code) 2) do large enough writes. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux')
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index dfd93d03f5d2..e4fd82e42104 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -286,7 +286,7 @@ struct tcp_sock {
__u32 max_window; /* Maximal window ever seen from peer */
__u32 pmtu_cookie; /* Last pmtu seen by socket */
__u32 mss_cache; /* Cached effective mss, not including SACKS */
- __u16 mss_cache_std; /* Like mss_cache, but without TSO */
+ __u16 xmit_size_goal; /* Goal for segmenting output packets */
__u16 ext_header_len; /* Network protocol overhead (IP/IPv6 options) */
__u8 ca_state; /* State of fast-retransmit machine */
__u8 retransmits; /* Number of unrecovered RTO timeouts. */