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Date: Tue, 27 Aug 2002 13:08:04 -0600 (MDT)
From: Thunder from the hill <thunder@lightweight.ods.org>
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To: Chris Wedgwood <cw@f00f.org>
cc: Alan Cox <alan@lxorguk.ukuu.org.uk>, Zheng Jian-Ming <zjm@cis.nctu.edu.tw>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: problems with changing UID/GID
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Hi,

On Tue, 27 Aug 2002, Chris Wedgwood wrote:
> On Tue, Aug 27, 2002 at 09:42:27AM -0600, Thunder from the hill wrote:
> 
>     I don't think this is cool. I mean, think of how many times we use
>     it, who will eat the overhead?
> 
> We use it almost never... a few times per process at most.  And the
> overhead will be nonexistent except in cases where the caller has to
> wait on the lock --- and in those cases it seems totally reasonable they
> *should* have to wait.

And how do you protect a caller from having to wait for the lock? You'd 
need a lock count here, where you can only change the credentials when the 
count is zero. But when will that ever be?

And btw, the count bumping/downing does cost. We need to do that sensibly.

			Thunder
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