Matt,

which commit is a bit complicated to say. Basically yes, the code is a
merge between the 2.6.32 kernel code we have for 10.04 and the Xen
patches SUSE had at that point in time. The "new" tree I am talking was
an effort to pick the patches from a newer release and try to work out
what is missing / has changed. Which is not that simple because the
rebase their tree onto something (which Xen source I never was able to
find out) and then refresh their patchset.

If you want to see yourself, you can find the current code at:
git://kernel.ubuntu.com/ubuntu/ubuntu-lucid.git
(check out the ec2 branch) and I have pushed the results of reworking the newer 
patchset to
git://kernel.ubuntu.com/smb/ubuntu-lucid.git
into the ec2-next branch there.

And IMO we do have ticket locks. Se drivers/xen/core/spinlocks.c in the
current ec2 branch. Also the fact that you actually see interrupt counts
for the spinlock IRQ. Compiling the ec2-next (maybe a bit optimistic
name) branch and run that, you will notice that spinlock are now
directly an event channel but also do not get incremented (because
compiling with compat set to 3.0.2 disables the ticket lock code).

Ok, so at least that does rule out the hypervisor poll call to be the
problem and we can go forward from there. And to repeat the answer to
your last question: yes based on SUSE. Be careful when reading code in
the ec2 tree. Is is a bit of a pain because it still contains all of the
2.6.32 upstream xen components, plus the SUSE (whatever xen version that
is based on). So arch/x86/xen is not used for the ec2 kernel, but
arch/x86/include/mach-xen/asm is as are copies of x86 files with -xen to
them and some parts in drivers/xen (those pulled in by CONFIG_XEN).

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to the bug report.
https://bugs.launchpad.net/bugs/929941

Title:
  Kernel deadlock in scheduler on m2.{2,4}xlarge EC2 instance

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux-ec2/+bug/929941/+subscriptions

-- 
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

Reply via email to