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[net-next,0/3] tipc: Confgiuration of MTU for media UDP

Message ID 1524128780-2550-1-git-send-email-mohan.krishna.ghanta.krishnamurthy@ericsson.com
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Series tipc: Confgiuration of MTU for media UDP | expand

Message

GhantaKrishnamurthy MohanKrishna April 19, 2018, 9:06 a.m. UTC 
Systematic measurements have shown that an emulated MTU of 14k for
UDP bearers is the optimal value for maximal throughput. Accordingly,
the default MTU of UDP bearers is changed to 14k.

We also provide users with a fallback option from this value,
by providing support to configure MTU for UDP bearers. The following
options are introduced which are symmetrical to the design of
confguring link tolerance.

- Configure media with new MTU value, which will take effect on
links going up after the moment it was configured. Alternatively,
the bearer has to be disabled and re-enabled, for existing links to
reflect the configured value.

- Configure bearer with new MTU value, which take effect on 
running links dynamically.

Please note:
- User has to change MTU at both endpoints, otherwise the link 
will fall back to smallest MTU after a reset.
- Failover from a link with higher MTU to a link with lower MTU

GhantaKrishnamurthy MohanKrishna (3):
  tipc: set default MTU for UDP media
  tipc: implement configuration of UDP media MTU
  tipc: confgiure and apply UDP bearer MTU on running links

 include/uapi/linux/tipc_config.h  |  5 +++++
 include/uapi/linux/tipc_netlink.h |  1 +
 net/tipc/bearer.c                 | 29 ++++++++++++++++++++++++++++-
 net/tipc/bearer.h                 |  3 +++
 net/tipc/node.c                   | 12 +++++++++---
 net/tipc/node.h                   |  2 +-
 net/tipc/udp_media.c              |  4 ++--
 net/tipc/udp_media.h              | 14 ++++++++++++++
 8 files changed, 63 insertions(+), 7 deletions(-)

Comments

David Miller April 20, 2018, 3:04 p.m. UTC | #1 
From: GhantaKrishnamurthy MohanKrishna <mohan.krishna.ghanta.krishnamurthy@ericsson.com>
Date: Thu, 19 Apr 2018 11:06:17 +0200

> Systematic measurements have shown that an emulated MTU of 14k for
> UDP bearers is the optimal value for maximal throughput. Accordingly,
> the default MTU of UDP bearers is changed to 14k.
> 
> We also provide users with a fallback option from this value,
> by providing support to configure MTU for UDP bearers. The following
> options are introduced which are symmetrical to the design of
> confguring link tolerance.
> 
> - Configure media with new MTU value, which will take effect on
> links going up after the moment it was configured. Alternatively,
> the bearer has to be disabled and re-enabled, for existing links to
> reflect the configured value.
> 
> - Configure bearer with new MTU value, which take effect on 
> running links dynamically.
> 
> Please note:
> - User has to change MTU at both endpoints, otherwise the link 
> will fall back to smallest MTU after a reset.
> - Failover from a link with higher MTU to a link with lower MTU

There are many negatives to using UDP in a way which causes
fragmentation, like this code now does.

But whatever, you guys can do whatever you want and get to keep the
pieces I guess :-)

Series applied.