Gerrit,
Comments inline.
On 11/17/06, Gerrit Renker <gerrit@xxxxxxxxxxxxxx> wrote:
It is great to see that this is picked up. It is one of the items
which I had put onto the ToDo >list as well,
the thread starting this began on
http://www.mail-archive.com/dccp%40vger.kernel.org/msg00446.html
That is the same bug as
http://www.mail-archive.com/dccp@xxxxxxxxxxxxxxx/msg00467.html which I
mentioned in my original email.
| Nov 3 02:27:46 localhost kernel: [44880.646538] tmp2 = 0 ccid3_hc_rx_calc_first_li: x_recv = 0, rtt =1
I wonder whether this is due to the RTT, due to the following statement in ccid3_hc_rx_calc_first_li:
if (rtt == 0)
rtt = 1;
Of course it is! I feel stupid I didn't find that one....
Maybe it would be good to print out when the RTT estimate is zero (with regard to the other email, I am still
puzzled about the Receiver-RTT measurement). The same statement re-appears in tfrc_calc_x (to avoid division-by-zero),
without warning.
I think that a warning message could bring in some light: maybe it is the case here that the RTT measurement is just
at rock bottom, always returns 0, and thus always stays at 1.
It was just put in there to stop divide by zeros. It wasn't meant to
be a proper fix.
It would be great if you could come up with something, you know this code best. I have put it into my `TBD' folder
and may just pester with emails later ;-)
Yes I will try and look at it all again when I get the chance.
There is another thread which I think may be of relevance, incidentally again at the rx_packet_recv function:
http://www.mail-archive.com/dccp%40vger.kernel.org/msg00118.html
This one has already been fixed. If you look at the code it's changed
a fair bit since then. This was a bug which crippled my testing and I
was glad to get sorted. I also removed some of the cc_val/window stuff
at this point as I figured 80% working was better than 0% working as
regards to congestion control...
Ian
--
Ian McDonald
Web: http://wand.net.nz/~iam4
Blog: http://imcdnzl.blogspot.com
WAND Network Research Group
Department of Computer Science
University of Waikato
New Zealand
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