diff options
| author | Yinghai Lu <yinghai@kernel.org> | 2008-12-05 18:58:31 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-12-08 14:31:51 +0100 |
| commit | 0b8f1efad30bd58f89961b82dfe68b9edf8fd2ac (patch) | |
| tree | 239251bad791fd60af8c0f2ba365b7188395c83f /include/linux/interrupt.h | |
| parent | 218d11a8b071b23b76c484fd5f72a4fe3306801e (diff) | |
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>
Diffstat (limited to 'include/linux/interrupt.h')
| -rw-r--r-- | include/linux/interrupt.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index f58a0cf8929..79e915e7e8a 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -18,6 +18,8 @@ #include <asm/ptrace.h> #include <asm/system.h> +extern int nr_irqs; + /* * These correspond to the IORESOURCE_IRQ_* defines in * linux/ioport.h to select the interrupt line behaviour. When |