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Date: Wed, 27 Oct 2010 16:45:02 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Robin Holt <holt@sgi.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
        Davide Libenzi <davidel@xmailserver.org>, linux-kernel@vger.kernel.org,
        Pekka Enberg <penberg@cs.helsinki.fi>
Subject: Re: [Patch] Convert max_user_watches to long.
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On Wed, 27 Oct 2010 14:09:15 -0500
Robin Holt <holt@sgi.com> wrote:

> On a 16TB machine, max_user_watches has an integer overflow.  Convert it
> to use a long and handle the associated fallout.
> 

hand-wavy reality check:

Are the existing defaults sane?  How well does the code perform with a
few billion watches?

Is the expected use case one-watch-per-user-per-fd?  If so, then
perhaps the max number of user_watches should have some realtionship
with the max number of fds?