On 08/16/2010 03:54 AM, Soren Hansen wrote:
On Mon, Aug 16, 2010 at 11:37:07AM +0200, Soren Hansen wrote:
> I'm running this on another kernel right now and I'm not seeing the
> problem. I'll try again with the kernel I used a couple of days ago.
Ok, found the other kernel. Same diff as in my previous e-mail, same
action. These are my results:
09:41:01.134: debug : umlMonitorCommand:698 : Run command 'config con0'
09:41:01.134: debug : umlMonitorCommand:733 : res.error: 6, res.extra: 0, res.length:
4096, res.data:
09:41:01.134: debug : umlMonitorCommand:736 : nbytes: 0
09:41:01.134: debug : umlMonitorCommand:738 : res.error: 0, res.extra: 0, res.length: 4,
res.data: pts
This one's a 2.6.34.1 kernel. The one where I didn't see the problem is
a 2.6.32.something-or-the-other kernel. Mindboggling.
Oh my. This really does look like a kernel bug. Can you confirm it
with an strace? Have you reported this regression to the right kernel
folks?
I guess it would help if we could write a simpler test program to
isolate whether this recvfrom bug exists in a bare minimum number of
syscalls. Meanwhile, I have no idea how to work around a buggy recvfrom
that doesn't return the correct number of bytes.
--
Eric Blake eblake(a)redhat.com +1-801-349-2682
Libvirt virtualization library
http://libvirt.org