[Bloat] SO_SNDBUF and SO_RCVBUF

[Eric Dumazet]

On Wed, 2015-04-22 at 15:20 -0700, Simon Barber wrote:
> Wouldn't the LOWAT setting be much easier for applications to use if it was 
> set in estimated time (ie time it will take to deliver the data) rather 
> than bytes?

Sure, but you have all the info to infer one from the other.

Note also TCP stack has immediate notion of bytes, while adding time
delays immediately impose a possibly expensive time acquisition in high
precision.

# git show c9bee3b7fdecb0c1d070c7b54113b3bdfb9a3d36 | diffstat -p1 -w70
 Documentation/networking/ip-sysctl.txt |   13 +++++++++++++
 include/linux/tcp.h                    |    1 +
 include/net/sock.h                     |   19 +++++++++++++------
 include/net/tcp.h                      |   14 ++++++++++++++
 include/uapi/linux/tcp.h               |    1 +
 net/ipv4/sysctl_net_ipv4.c             |    7 +++++++
 net/ipv4/tcp.c                         |    7 +++++++
 net/ipv4/tcp_ipv4.c                    |    1 +
 net/ipv4/tcp_output.c                  |    3 +++
 net/ipv6/tcp_ipv6.c                    |    1 +
 10 files changed, 61 insertions(+), 6 deletions(-)

A time based implementation would be way more complex/expensive.