[net-next,0/3] tcp: avoid sending too small packets

Message

Eric Dumazet April 18, 2024, 9:45 p.m. UTC

tcp_sendmsg() cooks 'large' skbs, that are later split
if needed from tcp_write_xmit().

After a split, the leftover skb size is smaller than the optimal
size, and this causes a performance drop.

In this series, tcp_grow_skb() helper is added to shift
payload from the second skb in the write queue to the first
skb to always send optimal sized skbs.

This increases TSO efficiency, and decreases number of ACK
packets.

Eric Dumazet (3):
  tcp: remove dubious FIN exception from tcp_cwnd_test()
  tcp: call tcp_set_skb_tso_segs() from tcp_write_xmit()
  tcp: try to send bigger TSO packets

 net/ipv4/tcp_output.c | 78 +++++++++++++++++++++++++++++--------------
 1 file changed, 53 insertions(+), 25 deletions(-)

Comments

[e-mail] April 22, 2024, 9:30 p.m. UTC | #1

Hello:

This series was applied to netdev/net-next.git (main)
by Jakub Kicinski <[e-mail]>:

On Thu, 18 Apr 2024 21:45:57 +0000 you wrote:
> tcp_sendmsg() cooks 'large' skbs, that are later split
> if needed from tcp_write_xmit().
> 
> After a split, the leftover skb size is smaller than the optimal
> size, and this causes a performance drop.
> 
> In this series, tcp_grow_skb() helper is added to shift
> payload from the second skb in the write queue to the first
> skb to always send optimal sized skbs.
> 
> [...]

Here is the summary with links:
  - [net-next,1/3] tcp: remove dubious FIN exception from tcp_cwnd_test()
    https://git.kernel.org/netdev/net-next/c/22555032c513
  - [net-next,2/3] tcp: call tcp_set_skb_tso_segs() from tcp_write_xmit()
    https://git.kernel.org/netdev/net-next/c/d5b38a71d333
  - [net-next,3/3] tcp: try to send bigger TSO packets
    https://git.kernel.org/netdev/net-next/c/8ee602c63520

You are awesome, thank you!