Re: Tickless/dyntick kernel, highres timer and general time crapectomy

["Franck Bui-Huu" <vagabon.xyz@gmail.com>]

Hi Ralf,

Ralf Baechle wrote:
> On Thu, Jun 07, 2007 at 04:44:11PM +0200, Franck Bui-Huu wrote:
>
> > >   No, it doesn't. Even on dyntick kernels, interrupts do happen several
> > > times a second. Dynticks have nothing to do with disabling timer
> > > interrupts...
> > That's true however if your system has 2 clock devices. One is the r4k-hpt
> > and the other one soemthing else with a higher rating. If you don't stop
> > r4k-hpt interrupts, how does it work ?
> To some degree this question is hypothetic because generally the cp0
> count/compare timer will be the highest rated counter.
Well it increments every other clock. So it's not impossible to have a
an other higher rated counter.

> But even if so, the basic solution is the same - just ignore the interrupt
> whenever it happens to be triggered.  Or if it isn't shared with an
> active performance counter interrupt, you could even disable_irq() it.
OK, but the current code doesn't seem to support very well multiple
clock event devices. For example the global_cd array is not updated if
a new clock event device is registered. Even ll_timer_interrupt()
handler should be renamed something like ll_hpt_interrupt() for
example.

Thanks,


--
              Franck