linux-kernel - Re: [PATCH 4/4] ARM: timer-sp: Set dynamic irq affinity

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Date:	Wed, 27 Feb 2013 10:34:21 +0530
From:	Santosh Shilimkar <santosh.shilimkar@...com>
To:	Viresh Kumar <viresh.kumar@...aro.org>
CC:	Daniel Lezcano <daniel.lezcano@...aro.org>,
	<john.stultz@...aro.org>, <tglx@...utronix.de>,
	<jacob.jun.pan@...ux.intel.com>,
	<linux-arm-kernel@...ts.infradead.org>, <linux-pm@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>, <linaro-kernel@...ts.linaro.org>,
	<patches@...aro.org>, <linus.walleij@...ricsson.com>
Subject: Re: [PATCH 4/4] ARM: timer-sp: Set dynamic irq affinity

On Wednesday 27 February 2013 10:29 AM, Viresh Kumar wrote:
> On 27 February 2013 10:26, Santosh Shilimkar <santosh.shilimkar@...com> wrote:
>> On Wednesday 27 February 2013 03:47 AM, Daniel Lezcano wrote:
>>>
>>> From: Viresh Kumar <viresh.kumar@...aro.org>
>>>
>>> When a cpu goes to a deep idle state where its local timer is shutdown, it
>>> notifies the time frame work 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.
>>>
>> Broad-cast device will only open the CPU for which the timer IRQ
>> affined to. And infact with subject series the affinity also is
>> updated for the CPU which owns the last timer expiry event.
>>
>> What am I missing here ?
>
> Dynamic affinity will work only if the following flag is set for a
> clock_event_device: CLOCK_EVT_FEAT_DYNIRQ, otherwise wakeup
> would happen on the cpu to which static affinity was set to.
>
I should have looked at the patches in order first :)
Sorry for the noise.

Regards,
Santosh
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