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Commit 2c6927a3 authored by Yinghai Lu's avatar Yinghai Lu Committed by Ingo Molnar
Browse files

irq: replace loop with nr_irqs with for_each_irq_desc 



There are a handful of loops that go from 0 to nr_irqs and use
get_irq_desc() on them. These would allocate all the irq_desc
entries, regardless of the need for them.

Use the smarter for_each_irq_desc() iterator that will only iterate
over the present ones.

v2: make sure arch without GENERIC_HARDIRQS work too

Signed-off-by: default avatarYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 9059d8fa

arch/x86/kernel/io_apic_64.c

+3 −3
Original line number Diff line number Diff line
@@ -1871,10 +1871,10 @@ static int migrate_irq_remapped_level(int irq) 


static void ir_irq_migration(struct work_struct *work)

{

	int irq;

	unsigned int irq;

	struct irq_desc *desc;



	for (irq = 0; irq < nr_irqs; irq++) {

		struct irq_desc *desc = irq_to_desc(irq);

	for_each_irq_desc(irq, desc) {

		if (desc->status & IRQ_MOVE_PENDING) {

			unsigned long flags;

arch/x86/kernel/irq_64.c

+2 −3
Original line number Diff line number Diff line
@@ -224,17 +224,16 @@ void fixup_irqs(cpumask_t map) 
{

	unsigned int irq;

	static int warned;

	struct irq_desc *desc;



	for (irq = 0; irq < nr_irqs; irq++) {

	for_each_irq_desc(irq, desc) {

		cpumask_t mask;

		int break_affinity = 0;

		int set_affinity = 1;

		struct irq_desc *desc;



		if (irq == 2)

			continue;



		desc = irq_to_desc(irq);

		/* interrupt's are disabled at this point */

		spin_lock(&desc->lock);

arch/x86/kernel/irqinit_64.c

+5 −12
Original line number Diff line number Diff line
@@ -142,25 +142,18 @@ void __init init_ISA_irqs(void) 
	init_bsp_APIC();

	init_8259A(0);



	for (i = 0; i < nr_irqs; i++) {

	for (i = 0; i < 16; i++) {

		struct irq_desc *desc = irq_to_desc(i);



		desc->status = IRQ_DISABLED;

		desc->action = NULL;

		desc->depth = 1;



		if (i < 16) {

		/*

		 * 16 old-style INTA-cycle interrupts:

		 */

		set_irq_chip_and_handler_name(i, &i8259A_chip,

						      handle_level_irq, "XT");

		} else {

			/*

			 * 'high' PCI IRQs filled in on demand

			 */

			desc->chip = &no_irq_chip;

		}

	}

}

include/linux/irq.h

+7 −0
Original line number Diff line number Diff line
@@ -202,9 +202,16 @@ extern struct irq_desc irq_desc[NR_IRQS]; 
extern struct irq_desc *irq_desc;

#endif



#ifdef CONFIG_GENERIC_HARDIRQS

#define for_each_irq_desc(irq, desc)		\

	for (irq = 0, desc = irq_desc; irq < nr_irqs; irq++, desc = &irq_desc[irq])

#endif



#else



extern struct irq_desc *sparse_irqs;

#define for_each_irq_desc(irqX, desc)		\

	for (desc = sparse_irqs, irqX = desc->irq; desc && irqX != -1U; desc = desc->next, irqX = desc ? desc->irq : -1U)



#endif

kernel/irq/internals.h

+2 −2
Original line number Diff line number Diff line
@@ -14,11 +14,11 @@ extern int __irq_set_trigger(struct irq_desc *desc, unsigned int irq, 
		unsigned long flags);



#ifdef CONFIG_PROC_FS

extern void register_irq_proc(unsigned int irq);

extern void register_irq_proc(unsigned int irq, struct irq_desc *desc);

extern void register_handler_proc(unsigned int irq, struct irqaction *action);

extern void unregister_handler_proc(unsigned int irq, struct irqaction *action);

#else

static inline void register_irq_proc(unsigned int irq) { }

static inline void register_irq_proc(unsigned int irq, struct irq_desc *desc) { }

static inline void register_handler_proc(unsigned int irq,

					 struct irqaction *action) { }

static inline void unregister_handler_proc(unsigned int irq,