Re: processes hung after sys_renameat, and 'missing' processes

[Linus Torvalds]

On Sun, Jun 3, 2012 at 3:36 PM, Dave Jones <davej@xxxxxxxxxx> wrote:
>
> It's still up and in this state if you want me to gather any further info
> before I reboot it.

You seem to have lockdep enabled, since I see the lock information,
but presumably you didn't get a lockdep splat before this?

Also, sysrq-w is usually way more interesting than 't' when there are
processes stuck on a mutex.

Because yes, it looks like you have a boattload of trinity processes
stuck on an inode mutex. Looks like every single one of them is in
'lock_rename()'. It *shouldn't* be an ABBA deadlock, since lockdep
should have noticed that, but who knows.

It looks like the lock information is somewhat truncated. I suspect
the dmesg buffer had filled up with all the task data.

Can you do just "sysrq-d" for the lock information (and maybe
separately "sysrq-w" for the blocked tasks)? The non-truncated lock
data might tell us more.

               Linus
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