Re: Finegrained a/c/mtime was Re: Directory notification problem

From: Padraig Brady (padraig@antefacto.com)
Date: Fri Oct 05 2001 - 07:44:20 EST


Andi Kleen wrote:

>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
>
But the point is you, only ever would want nano second resolution to make
sure you notice all changes to a file. A more general (and much simpler)
solution would be to gen_count++ every time a file's modified. What other
applications would require better than second resolution on files?

Padraig.

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