Commit 4a046d17 authored by Yinghai Lu's avatar Yinghai Lu Committed by Mike Travis
Browse files

x86: arch_probe_nr_irqs 



Impact: save RAM with large NR_CPUS, get smaller nr_irqs

Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
Signed-off-by: default avatarMike Travis <travis@sgi.com>
parent e65e49d0

arch/x86/include/asm/irq_vectors.h

+2 −5
Original line number Diff line number Diff line
@@ -115,14 +115,11 @@ 
# endif

#else



/* defined as a macro so nr_irqs = max_nr_irqs(nr_cpu_ids) can be used */

# define max_nr_irqs(nr_cpus)				\

	((8 * nr_cpus) > (32 * MAX_IO_APICS) ?		\

# define NR_IRQS					\

	((8 * NR_CPUS) > (32 * MAX_IO_APICS) ?		\

		(NR_VECTORS + (8 * NR_CPUS)) :		\

		(NR_VECTORS + (32 * MAX_IO_APICS)))	\



# define NR_IRQS max_nr_irqs(NR_CPUS)



#endif



#elif defined(CONFIG_X86_VOYAGER)

arch/x86/kernel/io_apic.c

+16 −0
Original line number Diff line number Diff line
@@ -3850,6 +3850,22 @@ void __init probe_nr_irqs_gsi(void) 
		nr_irqs_gsi = nr;

}



#ifdef CONFIG_SPARSE_IRQ

int __init arch_probe_nr_irqs(void)

{

	int nr;



	nr = ((8 * nr_cpu_ids) > (32 * nr_ioapics) ?

		(NR_VECTORS + (8 * nr_cpu_ids)) :

		(NR_VECTORS + (32 * nr_ioapics)));



	if (nr < nr_irqs && nr > nr_irqs_gsi)

		nr_irqs = nr;



	return 0;

}

#endif



/* --------------------------------------------------------------------------

                          ACPI-based IOAPIC Configuration

   -------------------------------------------------------------------------- */

include/linux/interrupt.h

+1 −0
Original line number Diff line number Diff line
@@ -467,6 +467,7 @@ int show_interrupts(struct seq_file *p, void *v); 
struct irq_desc;



extern int early_irq_init(void);

extern int arch_probe_nr_irqs(void);

extern int arch_early_irq_init(void);

extern int arch_init_chip_data(struct irq_desc *desc, int cpu);

kernel/irq/handle.c

+2 −7
Original line number Diff line number Diff line
@@ -59,10 +59,6 @@ EXPORT_SYMBOL_GPL(nr_irqs); 


#ifdef CONFIG_SPARSE_IRQ



#ifndef max_nr_irqs

#define max_nr_irqs(nr_cpus)	NR_IRQS

#endif



static struct irq_desc irq_desc_init = {

	.irq	    = -1,

	.status	    = IRQ_DISABLED,
@@ -138,8 +134,7 @@ int __init early_irq_init(void) 
	int i;



	 /* initialize nr_irqs based on nr_cpu_ids */

	nr_irqs = max_nr_irqs(nr_cpu_ids);



	arch_probe_nr_irqs();

	printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d\n", NR_IRQS, nr_irqs);



	desc = irq_desc_legacy;

kernel/softirq.c

+5 −0
Original line number Diff line number Diff line
@@ -795,6 +795,11 @@ int __init __weak early_irq_init(void) 
	return 0;

}



int __init __weak arch_probe_nr_irqs(void)

{

	return 0;

}



int __init __weak arch_early_irq_init(void)

{

	return 0;