From 0b8f1efad30bd58f89961b82dfe68b9edf8fd2ac Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Fri, 5 Dec 2008 18:58:31 -0800 Subject: 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 Signed-off-by: Ingo Molnar --- include/linux/interrupt.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/interrupt.h') 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 #include +extern int nr_irqs; + /* * These correspond to the IORESOURCE_IRQ_* defines in * linux/ioport.h to select the interrupt line behaviour. When -- cgit v1.2.3 From 0ebb26e7a4e2c5337502e98b2221e037fda911b9 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Fri, 12 Dec 2008 11:26:39 +0100 Subject: sparse irqs: handle !GENIRQ platforms Impact: build fix fix: In file included from /home/mingo/tip/arch/m68k/amiga/amiints.c:39: /home/mingo/tip/include/linux/interrupt.h:21: error: expected identifier or '(' /home/mingo/tip/arch/m68k/amiga/amiints.c: In function 'amiga_init_IRQ': Signed-off-by: Ingo Molnar --- include/linux/interrupt.h | 4 ++-- include/linux/irqnr.h | 11 ++++++++++- include/linux/random.h | 2 +- 3 files changed, 13 insertions(+), 4 deletions(-) (limited to 'include/linux/interrupt.h') diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 79e915e7e8a5..777f89e00b4a 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -14,12 +14,12 @@ #include #include #include +#include + #include #include #include -extern int nr_irqs; - /* * These correspond to the IORESOURCE_IRQ_* defines in * linux/ioport.h to select the interrupt line behaviour. When diff --git a/include/linux/irqnr.h b/include/linux/irqnr.h index 13754f813589..95d2b74641f5 100644 --- a/include/linux/irqnr.h +++ b/include/linux/irqnr.h @@ -1,6 +1,11 @@ #ifndef _LINUX_IRQNR_H #define _LINUX_IRQNR_H +/* + * Generic irq_desc iterators: + */ +#ifdef __KERNEL__ + #ifndef CONFIG_GENERIC_HARDIRQS #include # define nr_irqs NR_IRQS @@ -11,10 +16,12 @@ # define for_each_irq_desc_reverse(irq, desc) \ for (irq = nr_irqs - 1; irq >= 0; irq--) #else + +extern int nr_irqs; + #ifndef CONFIG_SPARSE_IRQ struct irq_desc; -extern int nr_irqs; # define for_each_irq_desc(irq, desc) \ for (irq = 0, desc = irq_desc; irq < nr_irqs; irq++, desc++) # define for_each_irq_desc_reverse(irq, desc) \ @@ -26,4 +33,6 @@ extern int nr_irqs; #define for_each_irq_nr(irq) \ for (irq = 0; irq < nr_irqs; irq++) +#endif /* __KERNEL__ */ + #endif diff --git a/include/linux/random.h b/include/linux/random.h index ad9daa2374d5..adbf3bd3c6b3 100644 --- a/include/linux/random.h +++ b/include/linux/random.h @@ -8,6 +8,7 @@ #define _LINUX_RANDOM_H #include +#include /* ioctl()'s for the random number generator */ @@ -49,7 +50,6 @@ struct timer_rand_state; extern struct timer_rand_state *irq_timer_state[]; -extern int nr_irqs; static inline struct timer_rand_state *get_timer_rand_state(unsigned int irq) { if (irq >= nr_irqs) -- cgit v1.2.3