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authorYinghai Lu <yinghai@kernel.org>2008-12-05 18:58:31 -0800
committerIngo Molnar <mingo@elte.hu>2008-12-08 14:31:51 +0100
commit0b8f1efad30bd58f89961b82dfe68b9edf8fd2ac (patch)
tree239251bad791fd60af8c0f2ba365b7188395c83f /include/linux/interrupt.h
parent218d11a8b071b23b76c484fd5f72a4fe3306801e (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.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index f58a0cf8929a..79e915e7e8a5 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