From owner-freebsd-dtrace@freebsd.org  Thu Mar 31 17:43:07 2016
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Date: Thu, 31 Mar 2016 20:42:56 +0300
From: Aleksander Alekseev <mail@eax.me>
To: Adrian Chadd <adrian.chadd@gmail.com>
Cc: Hans Petter Selasky <hps@selasky.org>, "freebsd-hackers@freebsd.org"
 <freebsd-hackers@freebsd.org>, Andriy Voskoboinyk <s3erios@gmail.com>,
 freebsd-dtrace@freebsd.org
Subject: Re: I need a little help in fixing `exclusive sleep mutex
 urtwn0_com_lock` in CURRENT
Message-ID: <20160331204256.5cb1fdaf@portege>
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> So as I understand some code acquired a mutex and didn't release it.
> And naturally it has something to do with USB. Now how can I figure
> out what code acquired this lock? Best approach I can think of
> currently is to find all places where this lock is accessed and add a
> debug logging. But perhaps there is a better way?

By any chance is it possible to trace mtx_lock / mtx_unlock calls using
DTrace? I see number of probes in `dtrace -l` which look like
something I need. Unfortunately they are named like knlist_mtx_lock or
do_lock_umutex so I can't figure out whether these are probes I looking
for or not.

cc: freebsd-dtrace@

-- 
Best regards,
Aleksander Alekseev
http://eax.me/