On Wed, 15 May 2024 at 19:27, Marco d'Itri <
md@linux.it> wrote:
On May 15, Job Snijders via Bird-users <bird-users@network.cz> wrote:
> But please be very careful in considering this patch, because it does
> introduce some subtle changes in the on-the-wire behaviour of BIRD. For
> example, without this patch an UPDATE for a handful of routes and the
> End-of-RIB marker might end up in the same TCP packet (if this fits);
> but with this patch, the End-of-RIB marker ends up in its own TCP
> packet. As things are today, setting TCP_NODELAY will increase the
I think that this can be fixed easily with TCP_CORK.
Basically, with TCP_NODELAY + TCP_CORK you can have the optimal balance
of latency and overhead without using writev.
Yes, thanks for sharing this suggestion.
Note that TCP_CORK is a Linux-only feature (on FreeBSD it seems aliased to TCP_NOPUSH, but I might be misunderstanding that code). There are subtle differences between NOPUSH and CORK: resetting CORK triggers a flush, whereas resetting NOPUSH does not.
It is of course reasonable to optimize one platform and not others, we work with the tools that we have - but a portable approach (using writev()?) would seem attractive to me :-)
Kind regards,
Job