linux-stable/include/linux/irqnr.h
Yinghai Lu 0b8f1efad3 sparse irq_desc[] array: core kernel and x86 changes
Impact: new feature

Problem on distro kernels: irq_desc[NR_IRQS] takes megabytes of RAM with
NR_CPUS set to large values. The goal is to be able to scale up to much
larger NR_IRQS value without impacting the (important) common case.

To solve this, we generalize irq_desc[NR_IRQS] to an (optional) array of
irq_desc pointers.

When CONFIG_SPARSE_IRQ=y is used, we use kzalloc_node to get irq_desc,
this also makes the IRQ descriptors NUMA-local (to the site that calls
request_irq()).

This gets rid of the irq_cfg[] static array on x86 as well: irq_cfg now
uses desc->chip_data for x86 to store irq_cfg.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-08 14:31:51 +01:00

16 lines
267 B
C

#ifndef _LINUX_IRQNR_H
#define _LINUX_IRQNR_H
#ifndef CONFIG_GENERIC_HARDIRQS
#include <asm/irq.h>
# define nr_irqs NR_IRQS
# define for_each_irq_desc(irq, desc) \
for (irq = 0; irq < nr_irqs; irq++)
static inline early_sparse_irq_init(void)
{
}
#endif
#endif