Current-Users archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]

Re: Hang when starting sshd on MP machine

On Mar 23, 2008, at 10:32, Andrew Doran wrote:
It avoids the problem.

  Right.  That's what I figured.

I think it's case of trying to understand where the dealock is coming from. It looks like a lock order reversal. I think what is happening is that one
thread is acquiring:

        kernel_lock -> kq_lock

.. and another is acquiring:

        kq_lock -> kernel_lock.

They both deadlock waiting for each other's lock. Given a quick look I
haven't been able to find that.

Makes sense. I can't build a kernel right now due to the rumpfs problem that's affecting things in -current, but after that, I could take a swing at this.

I'll chat with you off-list about the idea of maybe putting "I'm being locked by XXX" in both of those two places, then can look at the output. My Ultra2 is on a serial console, so printf-style debugging is often my choice for such things. :-)

                - Chris

Home | Main Index | Thread Index | Old Index