Messages in this thread | | | Date | Wed, 02 Jun 2010 15:55:30 +0100 | From | Ben McKeegan <> | Subject | Re: [Patch] fix packet loss and massive ping spikes with PPP multi-link |
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Ben McKeegan wrote: > Paul Mackerras wrote: > >>> I needed to do something similar a while back and I took a very >>> different approach, which I think is more flexible. Rather than >>> implement a new round-robin scheduler I simply introduced a target >>> minimum fragment size into the fragment size calculation, as a per >>> bundle parameter that can be configured via a new ioctl. This >>> modifies the algorithm so that it tries to limit the number of >>> fragments such that each fragment is at least the minimum size. If >>> the minimum size is greater than the packet size it will not be >>> fragmented all but will instead just get sent down the next >>> available channel. >>> >>> A pppd plugin generates the ioctl call allowing this to be tweaked >>> per connection. It is more flexible in that you can still have the >>> larger packets fragmented if you wish. >> >> I like this a lot better than the other proposed patch. It adds less >> code because it uses the fact that ppp_mp_explode() already has a >> round-robin capability using the ppp->nxchan field, plus it provides a >> way to control it per bundle via pppd. >> >> If you fix up the indentation issues (2-space indent in some of the >> added code -- if you're using emacs, set c-basic-offset to 8), I'll >> ack it and hopefully DaveM will pick it up. > > Okay, I'll fix it up when I'm back at work Tuesday and submit (today is > a UK public holiday) and also dig out and fix up the userspace code to > go with it.
Still working on this, updating the patch wasn't as trivial as I thought as it clashed with Gabriele Paoloni's ppp_mp_explode redesign. However, while looking at this code I believe I have found a bug which might have been contributing to the poor performance the OP was experiencing. For the case where channel speeds are unknown and there are more than 2 channels it would miscalculate the fragment sizes so they are not balanced on the channels.
Patch for the bug to follow immediately.
Regards, Ben.
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