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SubjectRe: [PATCH 0/4] time: dynamic irq affinity
On Wednesday 27 February 2013 03:47 AM, Daniel Lezcano wrote:
> When a cpu goes to a deep idle state where its local timer is shutdown,
> it notifies the time framework to use the broadcast timer instead.
>
> Unfortunately, the broadcast device could wake up any CPU, including an
> idle one which is not concerned by the wake up at all.
>
> This implies, in the worst case, an idle CPU will wake up to send an IPI
> to another idle cpu.
>
> This patch solves this by setting the irq affinity to the cpu concerned
> by the nearest timer event, by this way, the CPU which is wake up is
> guarantee to be the one concerned by the next event and we are safe with
> unnecessary wakeup for another idle CPU.
>
> As the irq affinity is not supported by all the archs, a flag is needed
> to specify which clocksource can handle it.
>
> Daniel Lezcano (3):
> time : pass broadcast parameter
> time : set broadcast irq affinity
> ARM: nomadik: add dynamic irq flag to the timer
>
> Viresh Kumar (1):
> ARM: timer-sp: Set dynamic irq affinity
>
Thanks Daniel for addressing the comments from earlier version. This
version looks good to me.

Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>

Regards,
Santosh
P.S: As I mentioned 'CLOCK_EVT_FEAT_DYNIRQ' optimization on
OMAP at least I found risky because you might end up missing
the asynchronous IPI wakeups because of the current SGI's
implementation. This must be true for other ARM platforms
as well.



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