Re: [PATCH v5 08/12] powerpc: Add support to mask perf interrupts and replay them

[Nicholas Piggin]

On Wed,  4 Jan 2017 17:19:46 +0530
Madhavan Srinivasan <ma...@linux.vnet.ibm.com> wrote:

> @@ -134,7 +137,7 @@ static inline bool arch_irqs_disabled(void)
>       _was_enabled = local_paca->soft_enabled;        \
>       local_paca->soft_enabled = IRQ_DISABLE_MASK_LINUX;\
>       local_paca->irq_happened |= PACA_IRQ_HARD_DIS;  \
> -     if (!(_was_enabled & IRQ_DISABLE_MASK_LINUX))   \
> +     if (!(_was_enabled & IRQ_DISABLE_MASK_ALL))     \
>               trace_hardirqs_off();                   \
>  } while(0)

Hang on, maybe there's some confusion about this. trace_hardirqs_off() is
for Linux irqs (i.e., local_irq_disable()), so that should continue to
test just the LINUX mask I think. Otherwise this

    powerpc_local_pmu_disable();
    hard_irq_disable();

Will miss calling trace_hardirqs_off(). You don't have a function that
disables PMU irqs without Linux irqs, but one might exist.

What I was concerned about is actually setting the disable mask to ALL

        local_paca->soft_enabled = IRQ_DISABLE_MASK_ALL;

No? Otherwise if you did

    powerpc_local_irq_pmu_disable();
    hard_irq_disable();

Then you would lose the PMU bit out of the mask.

Thanks,
Nick