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 --- drivers/xen/events.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'drivers/xen') diff --git a/drivers/xen/events.c b/drivers/xen/events.c index 1e3b934a4cf..2924faa7f6c 100644 --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -141,8 +141,12 @@ static void init_evtchn_cpu_bindings(void) int i; /* By default all event channels notify CPU#0. */ - for_each_irq_desc(i, desc) + for_each_irq_desc(i, desc) { + if (!desc) + continue; + desc->affinity = cpumask_of_cpu(0); + } #endif memset(cpu_evtchn, 0, sizeof(cpu_evtchn)); @@ -231,7 +235,7 @@ static int find_unbound_irq(void) int irq; /* Only allocate from dynirq range */ - for_each_irq_nr(irq) + for (irq = 0; irq < nr_irqs; irq++) if (irq_bindcount[irq] == 0) break; @@ -792,7 +796,7 @@ void xen_irq_resume(void) mask_evtchn(evtchn); /* No IRQ <-> event-channel mappings. */ - for_each_irq_nr(irq) + for (irq = 0; irq < nr_irqs; irq++) irq_info[irq].evtchn = 0; /* zap event-channel binding */ for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++) @@ -824,7 +828,7 @@ void __init xen_init_IRQ(void) mask_evtchn(i); /* Dynamic IRQ space is currently unbound. Zero the refcnts. */ - for_each_irq_nr(i) + for (i = 0; i < nr_irqs; i++) irq_bindcount[i] = 0; irq_ctx_init(smp_processor_id()); -- cgit v1.2.3-70-g09d2 From 6f8a0ed4e5d86c01db5e7e3f95d9003b7cf9cb87 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Wed, 17 Dec 2008 13:42:29 -0800 Subject: sparseirq, xen: make sure irq_desc is allocated for interrupts Impact: fix crash Make sure all Xen irqs have an irq_desc. Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Ingo Molnar --- drivers/xen/events.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/xen') diff --git a/drivers/xen/events.c b/drivers/xen/events.c index 2924faa7f6c..46625cd3874 100644 --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -233,6 +233,7 @@ static void unmask_evtchn(int port) static int find_unbound_irq(void) { int irq; + struct irq_desc *desc; /* Only allocate from dynirq range */ for (irq = 0; irq < nr_irqs; irq++) @@ -242,6 +243,10 @@ static int find_unbound_irq(void) if (irq == nr_irqs) panic("No available IRQ to bind to: increase nr_irqs!\n"); + desc = irq_to_desc_alloc_cpu(irq, 0); + if (WARN_ON(desc == NULL)) + return -1; + return irq; } -- cgit v1.2.3-70-g09d2