[vlc-devel] [PATCH 3/3] access/udp: reduce mtu amount on initial packets

[Ilkka Ollakka]

On Tue, Oct 16, 2018 at 04:48:09PM +0200, Francois Cartegnie wrote:
> Le 16/10/2018 à 16:19, Ilkka Ollakka a écrit :

> > With those packet sizes, the tinkered patch would set the mtu to be 1378 and
> > keep it on that. As it has the limits of mtu being over 1500 and then length
> > being between 1000 and 1500 to reduce the mtu size. It's not perfect, but
> > should work in this case?


> Slice trailing packet of payload + header == 1000 bytes and boom.

So you anticipate or have seen streams that have packet size just around
1000 bytes and unfrequently bigger packet that goes way over that?

The issue is not if the lower limit is 1000 or so, the thing that is
tried to address that we can spend huge buffer on first packet and
adjust the size on following packets when we see that it's not bigger
than normal mtu. As on stream duration that one packet overhead is
marginal compared to case when just in case we would use 64k buffer or
calling MSG_PEEK just in case before every receive.

-- 
Ilkka Ollakka
There is hardly a thing in the world that some man can not make a little
worse and sell a little cheaper.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: Digital signature
URL: <http://mailman.videolan.org/pipermail/vlc-devel/attachments/20181016/5ac7c04c/attachment.sig>