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@redhat.com +1-801-349-2682 Libvirt virtualization library http://libvirt.org