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Date: Sat, 24 Jan 2009 16:30:10 -0800
From: Alfred Perlstein <alfred@freebsd.org>
To: Maksim Yevmenkin <maksim.yevmenkin@gmail.com>
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Cc: freebsd-current@freebsd.org, current@freebsd.org,
	Hans Petter Selasky <hselasky@c2i.net>
Subject: Re: panic: mutex Giant not owned at
	/usr/src/sys/kern/tty_ttydisc.c:1127
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* Maksim Yevmenkin <maksim.yevmenkin@gmail.com> [090124 01:38] wrote:
> 
> from what i can see you are _NOT_ using _SPIN_ mutexes (aka spin
> locks). you are using regular mutexes. let me quote locking(9) man
> page
> 
> "
> Mutexes
>      Basically (regular) mutexes will deschedule the thread if the mutex can
>      not be acquired.  A non-spin mutex can be considered to be equivalent to
>      getting a write lock on an rw_lock (see below),
> "
> 
> so, if thread can not get mutex it will be descheduled. this
> absolutely can not happen in netgraph!

>From a purely academic standpoint... why can't netgraph use
standard mutexes?

Is there a pointer you can give me?

-Alfred