Re: [PATCH, RFC 2/8] ARM: twd: register clock event for 1 core SMP

[Santosh Shilimkar]

On Tuesday 19 February 2013 05:44 PM, Felipe Balbi wrote:
> On Tue, Feb 19, 2013 at 03:44:14PM +0530, Santosh Shilimkar wrote:
> > On Monday 18 February 2013 05:07 PM, Afzal Mohammed wrote:
> > > Register percpu local timer for scheduler tick in the case of one core
> > > SMP configuration. In other cases - secondary cpu's as well as boot
> > > cpu's having more than one core, this is being registered as per
> > > existing boot flow, with a difference that they happens after delay
> > > calibration. Registering the clock for tick in case of one core should
> > > be done before Kernel calibrates delay (this is required to boot,
> > > unless local timer is the only one registered for tick). Registering
> > > twd local timer at init_time (which platforms are doing now) helps
> > > achieve that with the proposed change.
> > >
> > > This helps in an almost booting Kernel (minimal) by only relying on
> > > ARM parts for an A9 one core SMP.
> > >
> > > Signed-off-by: Afzal Mohammed <afzal@xxxxxx>
> > > ---
> > As mentioned in cover-letter, I don't think we have good
> > reasoning to make TWD to work with UP configuration. Even
> > you fix the timer code, there are more cascaded dependencies
> > which is not worth the effort.
>
> if CONFIG_SMP_ON_UP is enabled, smp_twd.c can still be compiled, right ?
Yep though just from deps pesrpective TWD is made available for ARM SMP
machines as below

config HAVE_ARM_TWD
        bool
        depends on SMP

Regards,
Santosh
--
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/