Re: [PATCH v14 2/3] trace,x86: Introduce entering/exiting_irq()

From: Steven Rostedt
Date: Thu Jun 06 2013 - 14:26:22 EST


On Thu, 2013-06-06 at 11:23 -0400, Seiji Aguchi wrote:
> ---
> arch/x86/include/asm/apic.h | 27 +++++++++++++++++++++++++++
> 1 files changed, 27 insertions(+), 0 deletions(-)
>
> diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
> index 3388034..f8119b5 100644
> --- a/arch/x86/include/asm/apic.h
> +++ b/arch/x86/include/asm/apic.h
> @@ -12,6 +12,7 @@
> #include <asm/fixmap.h>
> #include <asm/mpspec.h>
> #include <asm/msr.h>
> +#include <asm/idle.h>
>
> #define ARCH_APICTIMER_STOPS_ON_C3 1
>
> @@ -687,5 +688,31 @@ extern int default_check_phys_apicid_present(int phys_apicid);
> #endif
>
> #endif /* CONFIG_X86_LOCAL_APIC */
> +extern void irq_enter(void);
> +extern void irq_exit(void);
> +
> +static inline void entering_irq(void)
> +{
> + irq_enter();
> + exit_idle();
> +}
> +
> +static inline void entering_ack_irq(void)
> +{
> + ack_APIC_irq();
> + entering_irq();
> +}
> +
> +static inline void exiting_irq(void)
> +{
> + irq_exit();
> +}
> +
> +static inline void exiting_ack_irq(void)
> +{
> + irq_exit();
> + /* Ack only at the end to avoid potential reentry */
> + ack_APIC_irq();
> +}
>
> #endif /* _ASM_X86_APIC_H */

I think it also makes sense to use these in this patch as well. That is,
go ahead and make the changes likes this:

@@ -919,17 +919,14 @@ void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs)
/*
* NOTE! We'd better ACK the irq immediately,
* because timer handling can be slow.
- */
- ack_APIC_irq();
- /*
+ *
* update_process_times() expects us to have done irq_enter().
* Besides, if we don't timer interrupts ignore the global
* interrupt lock, which is the WrongThing (tm) to do.
*/
- irq_enter();
- exit_idle();
+ entering_ack_irq();
local_apic_timer_interrupt();
- irq_exit();
+ exiting_irq();

set_irq_regs(old_regs);
}

And do that with all the interrupts.

I think this is getting close for adding to 3.11 queue.

-- Steve


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