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Date: Wed, 3 Oct 2001 23:26:09 +0200
From: Andi Kleen <ak@suse.de>
To: Alex Larsson <alexl@redhat.com>
Cc: Ulrich Drepper <drepper@cygnus.com>, Andi Kleen <ak@suse.de>,
        linux-kernel@vger.kernel.org
Subject: Re: Finegrained a/c/mtime was Re: Directory notification problem
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In-Reply-To: <Pine.LNX.4.33.0110031111470.29619-100000@devserv.devel.redhat.com>; from alexl@redhat.com on Wed, Oct 03, 2001 at 11:15:04AM -0400
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On Wed, Oct 03, 2001 at 11:15:04AM -0400, Alex Larsson wrote:
> Is a nanoseconds field the right choice though? In reality you might not 
> have a nanosecond resolution timer, so you would miss changes that appear
> on shorter timescale than the timer resolution. Wouldn't a generation 
> counter, increased when ctime was updated, be a better solution?

Near any CPU has a cycle counter builtin now, which gives you ns like
resolution. In theory you could still get collisions on MP systems, 
but window is small enough that it can be ignored in practice.

-Andi
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