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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/autoprobe.c
parent218d11a8b071b23b76c484fd5f72a4fe3306801e (diff)
downloadlinux-2.6.34-ux500-0b8f1efad30bd58f89961b82dfe68b9edf8fd2ac.tar.gz
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/autoprobe.c')
-rw-r--r--kernel/irq/autoprobe.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/kernel/irq/autoprobe.c b/kernel/irq/autoprobe.c
index cc0f7321b8c..650ce4102a6 100644
--- a/kernel/irq/autoprobe.c
+++ b/kernel/irq/autoprobe.c
@@ -40,6 +40,9 @@ unsigned long probe_irq_on(void)
* flush such a longstanding irq before considering it as spurious.
*/
for_each_irq_desc_reverse(i, desc) {
+ if (!desc)
+ continue;
+
spin_lock_irq(&desc->lock);
if (!desc->action && !(desc->status & IRQ_NOPROBE)) {
/*
@@ -68,6 +71,9 @@ unsigned long probe_irq_on(void)
* happened in the previous stage, it may have masked itself)
*/
for_each_irq_desc_reverse(i, desc) {
+ if (!desc)
+ continue;
+
spin_lock_irq(&desc->lock);
if (!desc->action && !(desc->status & IRQ_NOPROBE)) {
desc->status |= IRQ_AUTODETECT | IRQ_WAITING;
@@ -86,6 +92,9 @@ unsigned long probe_irq_on(void)
* Now filter out any obviously spurious interrupts
*/
for_each_irq_desc(i, desc) {
+ if (!desc)
+ continue;
+
spin_lock_irq(&desc->lock);
status = desc->status;
@@ -124,6 +133,9 @@ unsigned int probe_irq_mask(unsigned long val)
int i;
for_each_irq_desc(i, desc) {
+ if (!desc)
+ continue;
+
spin_lock_irq(&desc->lock);
status = desc->status;
@@ -166,6 +178,9 @@ int probe_irq_off(unsigned long val)
unsigned int status;
for_each_irq_desc(i, desc) {
+ if (!desc)
+ continue;
+
spin_lock_irq(&desc->lock);
status = desc->status;