Re: [PATCH] [RFC] timerfd: add TFD_NOTIFY_CLOCK_SET to watch forclock changes

From: john stultz
Date: Wed Dec 01 2010 - 18:47:00 EST


On Wed, 2010-12-01 at 17:46 -0500, Valdis.Kletnieks@xxxxxx wrote:
> On Wed, 01 Dec 2010 10:43:59 GMT, Jamie Lokier said:
>
> > So maybe CLOCK_MONOTONIC should be changed to include elapsed time
> > during suspend/resume, and CLOCK_MONOTONIC_RAW could remain as it is,
> > for programs that want that?
>
> Wouldn't that be an API break for programs that are expecting the current
> behavior of CLOCK_MONOTONIC? Yes, there should be a way to request either of
> them - but if there's only one way now, it should continue to act the current
> way, and the added way is the second option.

We do keep track of the amount of time in suspend (total_sleep_time), so
creating a new clockid to provide CLOCK_MONOTONIC + total_sleep_time
wouldn't be hard. We just haven't had a clear articulation of why it
would be useful to expose to userland (nor a clear name to describe
exactly what it represents).

thanks
-john


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/