Re: [PATCH] x86: io_apic: Move and reenable irq only whenCONFIG_GENERIC_PENDING_IRQ=y

From: Ingo Molnar
Date: Fri Mar 02 2012 - 04:40:18 EST



* Alexander Gordeev <agordeev@xxxxxxxxxx> wrote:

> When CONFIG_GENERIC_PENDING_IRQ=n irq move and reenable code is never get
> executed, nor do_unmask_irq variable updates its init value. Move both the
> code and do_unmask_irq under CONFIG_GENERIC_PENDING_IRQ macro.
>
> Signed-off-by: Alexander Gordeev <agordeev@xxxxxxxxxx>
> ---
> arch/x86/kernel/apic/io_apic.c | 7 ++++++-
> 1 files changed, 6 insertions(+), 1 deletions(-)
>
> diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
> index fb07275..57dec14 100644
> --- a/arch/x86/kernel/apic/io_apic.c
> +++ b/arch/x86/kernel/apic/io_apic.c
> @@ -2515,8 +2515,11 @@ atomic_t irq_mis_count;
> static void ack_apic_level(struct irq_data *data)
> {
> struct irq_cfg *cfg = data->chip_data;
> - int i, do_unmask_irq = 0, irq = data->irq;
> + int i, irq = data->irq;
> unsigned long v;
> +#ifdef CONFIG_GENERIC_PENDING_IRQ
> + int do_unmask_irq = 0;
> +#endif
>
> irq_complete_move(cfg);
> #ifdef CONFIG_GENERIC_PENDING_IRQ
> @@ -2581,6 +2584,7 @@ static void ack_apic_level(struct irq_data *data)
> eoi_ioapic_irq(irq, cfg);
> }
>
> +#ifdef CONFIG_GENERIC_PENDING_IRQ
> /* Now we can move and renable the irq */
> if (unlikely(do_unmask_irq)) {
> /* Only migrate the irq if the ack has been received.
> @@ -2613,6 +2617,7 @@ static void ack_apic_level(struct irq_data *data)
> irq_move_masked_irq(data);
> unmask_ioapic(cfg);
> }
> +#endif

The two CONFIG_GENERIC_PENDING_IRQ blocks should be moved out
into two helper inline functions right in front of
ack_apic_level() so that we do not complicate ack_apic_level()
with so many #ifdefs.

They'd have the form of:

int masked = 0;

masked = ioapic_irqd_mask(data, cfg);

...

ioapic_irqd_unmask(data, cfg, masked);

or so.

Thanks,

Ingo
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