Commit c09cb129 authored by Shijith Thotton's avatar Shijith Thotton Committed by Thomas Gleixner
Browse files

genirq: Update irq stats from NMI handlers 



The NMI handlers handle_percpu_devid_fasteoi_nmi() and handle_fasteoi_nmi()
do not update the interrupt counts. Due to that the NMI interrupt count
does not show up correctly in /proc/interrupts.

Add the statistics and treat the NMI handlers in the same way as per cpu
interrupts and prevent them from updating irq_desc::tot_count as this might
be corrupted due to concurrency.

[ tglx: Massaged changelog ]

Fixes: 2dcf1fbc ("genirq: Provide NMI handlers")
Signed-off-by: default avatarShijith Thotton <sthotton@marvell.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1562313336-11888-1-git-send-email-sthotton@marvell.com
parent 9b979ac3

kernel/irq/chip.c

+4 −0
Original line number Diff line number Diff line
@@ -748,6 +748,8 @@ void handle_fasteoi_nmi(struct irq_desc *desc) 
	unsigned int irq = irq_desc_get_irq(desc);

	irqreturn_t res;



	__kstat_incr_irqs_this_cpu(desc);



	trace_irq_handler_entry(irq, action);

	/*

	 * NMIs cannot be shared, there is only one action.
@@ -962,6 +964,8 @@ void handle_percpu_devid_fasteoi_nmi(struct irq_desc *desc) 
	unsigned int irq = irq_desc_get_irq(desc);

	irqreturn_t res;



	__kstat_incr_irqs_this_cpu(desc);



	trace_irq_handler_entry(irq, action);

	res = action->handler(irq, raw_cpu_ptr(action->percpu_dev_id));

	trace_irq_handler_exit(irq, action, res);

kernel/irq/irqdesc.c

+7 −1
Original line number Diff line number Diff line
@@ -946,6 +946,11 @@ unsigned int kstat_irqs_cpu(unsigned int irq, int cpu) 
			*per_cpu_ptr(desc->kstat_irqs, cpu) : 0;

}



static bool irq_is_nmi(struct irq_desc *desc)

{

	return desc->istate & IRQS_NMI;

}



/**

 * kstat_irqs - Get the statistics for an interrupt

 * @irq:	The interrupt number
@@ -963,7 +968,8 @@ unsigned int kstat_irqs(unsigned int irq) 
	if (!desc || !desc->kstat_irqs)

		return 0;

	if (!irq_settings_is_per_cpu_devid(desc) &&

	    !irq_settings_is_per_cpu(desc))

	    !irq_settings_is_per_cpu(desc) &&

	    !irq_is_nmi(desc))

	    return desc->tot_count;



	for_each_possible_cpu(cpu)

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