On Wed, 2009-02-04 at 14:29 +0000, Daniel Walker wrote: > On Mon, 2008-12-15 at 08:26 -0800, John Stultz wrote: > > > Nice. The cyclecounter struct can work as a good base that I can shift > > the clocksource bits over to as I clean that up. > > > > We will probably want to split this out down the road, but for now its > > small enough and related enough that I think its fine in the > > clocksource.h/c. > > > > Also since Magnus has been working on it, does enable/disable accessors > > in the cyclecounter struct make sense for your hardware as well? > > > > Also the corner cases on overflows (how we manage the state, should > > reads be deferred for too long) will need to be addressed, but I guess > > we can solve that when it becomes an issue. Just to be clear: none of > > the hardware you're submitting this round has wrapping issues? Or is > > that not the case? > > Why wouldn't this just use a clocksource directly and not register it > with the timekeeping? The cyclecounter is just a subset of the > clocksource .. The very first revision of the patch did exactly that: http://kerneltrap.org/mailarchive/linux-netdev/2008/11/19/4164204 The patch was smaller, but it also took some shortcuts (reusing fields meant to be used in a different way) and added other unused fields to the user of such an independent clocksource instance. I agree with John that separate structures for different aspects of the problem (abstract API for read-only access to hardware; converting cycle counter into continuously increasing time counter) is the cleaner approach. -- Best Regards, Patrick Ohly The content of this message is my personal opinion only and although I am an employee of Intel, the statements I make here in no way represent Intel's position on the issue, nor am I authorized to speak on behalf of Intel on this matter. -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html