On Sep 14, 2006, at 2:12 AM, Pavel Machek wrote: > Hi! > >>>> Date: Mon, 11 Sep 2006 21:36:37 +0200 >>>> From: Pavel Machek <pavel at ucw.cz> >>>> >>>> Kernel interface is not something to be experimented with. >>> >>> Disagree. How else to get it right?? >>> Try, learn, improve. That's experimentation. >>> Linux has no "stable API nonsense" ... >>> >>> The point of "cathedral vs. bazaar" was that experimentation >>> and evolution are more successful processes than "get it >>> right the first time". >> --- >> >> I think Pavel's point was that the userspace interface to >> the kernel (at least the syscall interface) is stable (open to >> Extension by addition of syscalls, but closed to modification >> or deletion of existing and that any experimentation needs to >> happen before functionality goes into the mainstream. > > Yes, that was my point. (And I'd add "plus you can't get around that > by introducing interface hidden by #ifdef"). > >> That said, I do think we probably need to add a new interface to >> cover operating points, because some of believe that policy needs >> to be in user space and the whole point of the OP abstraction is >> that operating points are atomic. You can't just add knobs to >> control more factors, because all those knobs need to be turned >> at the same time. Setting an operating point is inherently an >> atomic operation, not n separate operations that can be taken >> serially. > > Ok, "needs to be atomic" is first real argument for OP abstraction. I > wonder if we can get around that by delaying the transaction until > userspace tells us it made all the changes... otoh that is going to be > messy. > > But do you have some reasonable way to integrate OP with cpufreq? Yes, it was presented in the PowerOP/cpufreq integration patches. The cpufreq_driver layer is the natural integration point. > > Pavel > -- > (english) http://www.livejournal.com/~pavelmachek > (cesky, pictures) > http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html > _______________________________________________ > linux-pm mailing list > linux-pm at lists.osdl.org > https://lists.osdl.org/mailman/listinfo/linux-pm >
