Re: [PATCH V9 1/3] irq: Allow to pass the IRQF_TIMER flag with percpu irq request

Krzysztof Kozlowski
2017-04-24T18:33:38Z

On Mon, Apr 24, 2017 at 04:01:31PM +0200, Daniel Lezcano wrote:
> In the next changes, we track when the interrupts occur in order to
> statistically compute when is supposed to happen the next interrupt.
>
> In all the interruptions, it does not make sense to store the timer interrupt
> occurences and try to predict the next interrupt as when know the expiration
> time.
>
> The request_irq() has a irq flags parameter and the timer drivers use it to
> pass the IRQF_TIMER flag, letting us know the interrupt is coming from a timer.
> Based on this flag, we can discard these interrupts when tracking them.
>
> But, the API request_percpu_irq does not allow to pass a flag, hence specifying
> if the interrupt type is a timer.
>
> Add a function request_percpu_irq_flags() where we can specify the flags. The
> request_percpu_irq() function is changed to be a wrapper to
> request_percpu_irq_flags() passing a zero flag parameter.
>
> Change the timers using request_percpu_irq() to use request_percpu_irq_flags()
> instead with the IRQF_TIMER flag set.
>
> For now, in order to prevent a misusage of this parameter, only the IRQF_TIMER
> flag (or zero) is a valid parameter to be passed to the
> request_percpu_irq_flags() function.
>
> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Vineet Gupta <vgupta@synopsys.com>
> Cc: Marc Zyngier <marc.zyngier@arm.com>
> Cc: Patrice Chotard <patrice.chotard@st.com>
> Cc: Kukjin Kim <kgene@kernel.org>
> Cc: Krzysztof Kozlowski <krzk@kernel.org>
> Cc: Javier Martinez Canillas <javier@osg.samsung.com>
> Cc: Christoffer Dall <christoffer.dall@linaro.org>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Radim Krčmář <rkrcmar@redhat.com>
>
> ---
> Changelog:
>
> V9:
> - Clarified the patch description
> - Fixed EXPORT_SYMBOL_GPL(request_percpu_irq_flags)
> ---
> arch/arm/kernel/smp_twd.c | 3 ++-
> drivers/clocksource/arc_timer.c | 4 ++--
> drivers/clocksource/arm_arch_timer.c | 20 ++++++++++++--------
> drivers/clocksource/arm_global_timer.c | 4 ++--
> drivers/clocksource/exynos_mct.c | 7 ++++---
> drivers/clocksource/qcom-timer.c | 4 ++--
> drivers/clocksource/time-armada-370-xp.c | 9 +++++----
> drivers/clocksource/timer-nps.c | 6 +++---
> include/linux/interrupt.h | 11 ++++++++++-
> kernel/irq/manage.c | 15 ++++++++++-----
> virt/kvm/arm/arch_timer.c | 5 +++--
> 11 files changed, 55 insertions(+), 33 deletions(-)
>

For exynos-mct:
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>

Best regards,
Krzysztof