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From: John Baldwin <jhb@freebsd.org>
To: freebsd-current@freebsd.org
Subject: Re: Filesystem wedges caused by r251446
Date: Tue, 9 Jul 2013 12:02:24 -0400
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 (bigwig.baldwin.cx); Tue, 09 Jul 2013 12:12:41 -0400 (EDT)
Cc: Konstantin Belousov <kostikbel@gmail.com>, Ian FREISLICH <ianf@clue.co.za>
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On Thursday, July 04, 2013 5:03:29 am Ian FREISLICH wrote:
> Konstantin Belousov wrote:
> > 
> > Care to provide any useful information ?
> > 
> > http://www.freebsd.org/doc/en_US.ISO8859-1/books/developers-
handbook/kerneldebug-deadlocks.html
> 
> Well, the system doesn't deadlock it's perfectly useable so long
> as you don't touch the file that's wedged.  A lot of the time the
> userland process is unkillable, but often it is killable.  How do
> I get from from the PID to where the FS is stuck in the kernel?

Use kgdb.  'proc <pid>', then 'bt'.

-- 
John Baldwin