Commit c2b1063e authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

genirq: Add a IRQF_NO_DEBUG flag 



The whole call to note_interrupt() can be avoided or return early when
interrupts would be marked accordingly. For IPI handlers which always
return HANDLED the whole procedure is pretty pointless to begin with.

Add a IRQF_NO_DEBUG flag and mark the interrupt accordingly if supplied
when the interrupt is requested.

When noirqdebug is set on the kernel commandline, then the interrupt is
marked unconditionally so that there is only one condition in the hotpath
to evaluate.

 [ clg: Add changelog ]

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarCédric Le Goater <clg@kaod.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/7a8ad02f-63a8-c1aa-fdd1-39d973593d02@kaod.org
parent d07f6ca9

include/linux/interrupt.h

+3 −0
Original line number Diff line number Diff line
@@ -64,6 +64,8 @@ 
 * IRQF_NO_AUTOEN - Don't enable IRQ or NMI automatically when users request it.

 *                Users will enable it explicitly by enable_irq() or enable_nmi()

 *                later.

 * IRQF_NO_DEBUG - Exclude from runnaway detection for IPI and similar handlers,

 *		   depends on IRQF_PERCPU.

 */

#define IRQF_SHARED		0x00000080

#define IRQF_PROBE_SHARED	0x00000100
@@ -78,6 +80,7 @@ 
#define IRQF_EARLY_RESUME	0x00020000

#define IRQF_COND_SUSPEND	0x00040000

#define IRQF_NO_AUTOEN		0x00080000

#define IRQF_NO_DEBUG		0x00100000



#define IRQF_TIMER		(__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD)

include/linux/irq.h

+2 −0
Original line number Diff line number Diff line
@@ -72,6 +72,7 @@ enum irqchip_irq_state; 
 *				  mechanism and from core side polling.

 * IRQ_DISABLE_UNLAZY		- Disable lazy irq disable

 * IRQ_HIDDEN			- Don't show up in /proc/interrupts

 * IRQ_NO_DEBUG			- Exclude from note_interrupt() debugging

 */

enum {

	IRQ_TYPE_NONE		= 0x00000000,
@@ -99,6 +100,7 @@ enum { 
	IRQ_IS_POLLED		= (1 << 18),

	IRQ_DISABLE_UNLAZY	= (1 << 19),

	IRQ_HIDDEN		= (1 << 20),

	IRQ_NO_DEBUG		= (1 << 21),

};



#define IRQF_MODIFY_MASK	\

kernel/irq/chip.c

+1 −1
Original line number Diff line number Diff line
@@ -481,7 +481,7 @@ void handle_nested_irq(unsigned int irq) 
	for_each_action_of_desc(desc, action)

		action_ret |= action->thread_fn(action->irq, action->dev_id);



	if (!noirqdebug)

	if (!irq_settings_no_debug(desc))

		note_interrupt(desc, action_ret);



	raw_spin_lock_irq(&desc->lock);

kernel/irq/handle.c

+1 −1
Original line number Diff line number Diff line
@@ -197,7 +197,7 @@ irqreturn_t handle_irq_event_percpu(struct irq_desc *desc) 


	add_interrupt_randomness(desc->irq_data.irq, flags);



	if (!noirqdebug)

	if (!irq_settings_no_debug(desc))

		note_interrupt(desc, retval);

	return retval;

}

kernel/irq/manage.c

+5 −0
Original line number Diff line number Diff line
@@ -1686,8 +1686,13 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) 
		if (new->flags & IRQF_PERCPU) {

			irqd_set(&desc->irq_data, IRQD_PER_CPU);

			irq_settings_set_per_cpu(desc);

			if (new->flags & IRQF_NO_DEBUG)

				irq_settings_set_no_debug(desc);

		}



		if (noirqdebug)

			irq_settings_set_no_debug(desc);



		if (new->flags & IRQF_ONESHOT)

			desc->istate |= IRQS_ONESHOT;