Date: Fri, 3 Sep 2004 01:06:28 -0700
From: William Lee Irwin III <wli@holomorphy.com>
To: Kirill Korotaev <dev@sw.ru>
Cc: torvalds@osdl.org, dtor_core@ameritech.net, linux-kernel@vger.kernel.org
Subject: Re: INIT hangs with tonight BK pull (2.6.9-rc1+)
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	Kirill Korotaev <dev@sw.ru>, torvalds@osdl.org,
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At some point in the past, Dmitry Torokhov wrote:
>> Well, I was excited about blowing away 100B from each task but am now
>> a bit concerned about the semantic impact of the refcounting part of it.
>> It's unclear what pins an ID while a tty has a reference to it without
>> the reference counting; Kirill, could you answer this?

On Fri, Sep 03, 2004 at 12:09:10PM +0400, Kirill Korotaev wrote:
> stop.
> tty doesn't hold reference to ID neither in my patch nor in the original 
> kernel.
> tty only knows session ID and wants to traverse all tasks with such ID. 
> if task dies it calls detach_pid() and it won't be found in such a loop.
> No reference counting is required.
> The problem was in loop. Or more exactly my 
> do_each_task_pid()/while_each_task_pid() macros were incompatible with 
> continue statement inside. It was really foolish error. Like the most are...

Well, that sounds easy enough to deal with. I suppose the reference
counting argument is that the refcounting is on the tty by the tasks
and not vice-versa, and disassociate_ctty() cleans up the SID reference.


-- wli
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