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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 /kernel/irq/chip.c
parent218d11a8b071b23b76c484fd5f72a4fe3306801e (diff)
downloadblackbird-op-linux-0b8f1efad30bd58f89961b82dfe68b9edf8fd2ac.tar.gz
blackbird-op-linux-0b8f1efad30bd58f89961b82dfe68b9edf8fd2ac.zip
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 'kernel/irq/chip.c')
-rw-r--r--kernel/irq/chip.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 10b5092e9bfe..8e4fce4a1b1f 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -24,9 +24,10 @@
*/
void dynamic_irq_init(unsigned int irq)
{
- struct irq_desc *desc = irq_to_desc(irq);
+ struct irq_desc *desc;
unsigned long flags;
+ desc = irq_to_desc(irq);
if (!desc) {
WARN(1, KERN_ERR "Trying to initialize invalid IRQ%d\n", irq);
return;
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