[PATCH 0/3] NVMe/TCP: support specifying the congestion-control

[Mingbao Sun]

From: Mingbao Sun <tyler.sun at dell.com>

Hi all,

congestion-control could have a noticeable impaction on the
performance of TCP-based communications. This is of course true
to NVMe_over_TCP.

Different congestion-controls (e.g., cubic, dctcp) are suitable for
different scenarios. Proper adoption of congestion control would benefit
the performance. On the contrary, the performance could be destroyed.

Though we can specify the congestion-control of NVMe_over_TCP via
writing '/proc/sys/net/ipv4/tcp_congestion_control', but this also
changes the congestion-control of all the future TCP sockets that
have not been explicitly assigned the congestion-control, thus bringing
potential impaction on their performance.

So it makes sense to make NVMe_over_TCP support specifying the
congestion-control.

patch 1/3 export a symbol on behalf of the following ones.
patch 2/3 addresses the NVMe/TCP host side.
patch 3/3 addresses the NVMe/TCP target side.

Since the change made to netdev is pretty simple, so the patch
is generated against nvme-5.18 of the nvme.git.

Mingbao Sun (3):
  tcp: export symbol tcp_set_congestion_control
  nvme-tcp: support specifying the congestion-control
  nvmet-tcp: support specifying the congestion-control

 drivers/nvme/host/fabrics.c    | 12 +++++++++++
 drivers/nvme/host/fabrics.h    |  2 ++
 drivers/nvme/host/tcp.c        | 15 +++++++++++++-
 drivers/nvme/target/configfs.c | 37 ++++++++++++++++++++++++++++++++++
 drivers/nvme/target/nvmet.h    |  1 +
 drivers/nvme/target/tcp.c      | 11 ++++++++++
 net/ipv4/tcp_cong.c            |  1 +
 7 files changed, 78 insertions(+), 1 deletion(-)

-- 
2.26.2