Re: [PATCHv3 linux-next] hrtimer: Add notifier when clock_was_setwas called

From: Herbert Xu
Date: Thu Sep 12 2013 - 09:44:35 EST


On Thu, Sep 12, 2013 at 03:21:24PM +0200, Thomas Gleixner wrote:
>
> > (3): http://www.spinics.net/lists/netdev/msg245169.html
>
> Thanks for the explanation so far.
>
> What's still unclear to me is why these timeouts are bound to wall
> time in the first place.
>
> Is there any real reason why the key life time can't simply be
> expressed in monotonic time, e.g. N seconds after creation or M
> seconds after usage? Looking at the relevant RFCs I can't find any
> requirement for binding the life time to wall time.
>
> A life time of 10 minutes does not change when the wall clock is
> adjusted for whatever reasons. It's still 10 minutes and not some
> random result of the wall clock adjustments. But I might be wrong as
> usual :)

Well we started out with straight timers. It was changed because
people wanted IPsec SAs to expire after a suspect/resume which
AFAIK does not touch normal timers.

Of course, this brought with it a new set of problems when the
system time is stepped which now cause SAs to expire even though
they probably shouldn't.

Cheers,
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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