Re: [Xen-devel] (repeatable) cross-domain networking failure

[mukesh agrawal <xen.sourceforge.net@xxxxxxxxxxxxxxxxxxx>]

On Sun, 16 Jan 2005, Keir Fraser wrote:

> This corroborates my intial guess that the backend driver (in DOM0) is
> sending the packets into the DOM0 networking layer, and never hearing
> back when the packet is freed. Normally this would trigger a response
> to be sent back to the domU and resources in the backend driver would
> get freed up. This isn't happening and you eventually hit a limit on
> the number of packets that the driver will simultaneously put in
> flight.
When you say "resources in the backend driver would get freed up", that's 
the domU (sender) backend driver?
> Either those UDP packets are queued up somewhere in the DOM0 network
> stack, or the destructor callback is not getting called for some
> reason or has got overwritten(!).
Well, the packets aren't stuck in the dom0 network stack... They get 
delivered all the way up to the application just fine (nc in the trivial 
test case). So I think it must be the latter... After delivering the UDP 
packet to the application, the destructor is not being called back.
Further, this seems to be specific to the receive path for packets 
delivered to userspace (since traffic to the kernel NFS server doesn't 
seem to trigger it, nor traffic to closed ports).
What (specific source files or documentation) would you suggest starting 
at, to see an example of how the destruction is supposed to be done? I 
guess the TCP receive code works properly, so maybe I should compare that 
to the UDP code?
Thanks,
mukesh



-------------------------------------------------------
The SF.Net email is sponsored by: Beat the post-holiday blues
Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek.
It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.sourceforge.net/lists/listinfo/xen-devel