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| author | Mike Travis <travis@sgi.com> | 2009-01-10 22:24:06 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-01-11 19:13:35 +0100 |
| commit | 0fa0ebbf15addc1be8f73325d809c8547a9de304 (patch) | |
| tree | cd995419a3eb84d3e18e92ff205af86a7a4ed66d | |
| parent | e2f4d06545ec1f29b0e838ee34cbf3500ea5b9a4 (diff) | |
| download | linux-0fa0ebbf15addc1be8f73325d809c8547a9de304.tar.gz linux-0fa0ebbf15addc1be8f73325d809c8547a9de304.tar.bz2 linux-0fa0ebbf15addc1be8f73325d809c8547a9de304.zip | |
irq: allocate irq_desc_ptrs array based on nr_irqs
Impact: allocate irq_desc_ptrs in preparation for making it variable-sized.
This addresses this memory usage bump when NR_CPUS bumped from 128 to 4096:
34816 +229376 264192 +658% irq_desc_ptrs(.data.read_mostly)
The patch is split into two parts, the first simply allocates the
irq_desc_ptrs array. Then next will deal with making it variable.
This is only when CONFIG_SPARSE_IRQS=y.
Signed-off-by: Mike Travis <travis@sgi.com>
| -rw-r--r-- | kernel/irq/handle.c | 11 | ||||
| -rw-r--r-- | kernel/irq/internals.h | 7 |
2 files changed, 16 insertions, 2 deletions
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index fd1ef16252f4..d0b8f7e72790 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -17,6 +17,7 @@ #include <linux/kernel_stat.h> #include <linux/rculist.h> #include <linux/hash.h> +#include <linux/bootmem.h> #include "internals.h" @@ -110,7 +111,7 @@ static void init_one_irq_desc(int irq, struct irq_desc *desc, int cpu) */ DEFINE_SPINLOCK(sparse_irq_lock); -struct irq_desc *irq_desc_ptrs[NR_IRQS] __read_mostly; +struct irq_desc **irq_desc_ptrs __read_mostly; static struct irq_desc irq_desc_legacy[NR_IRQS_LEGACY] __cacheline_aligned_in_smp = { [0 ... NR_IRQS_LEGACY-1] = { @@ -137,6 +138,9 @@ int __init early_irq_init(void) desc = irq_desc_legacy; legacy_count = ARRAY_SIZE(irq_desc_legacy); + /* allocate irq_desc_ptrs array based on nr_irqs */ + irq_desc_ptrs = alloc_bootmem(nr_irqs * sizeof(void *)); + for (i = 0; i < legacy_count; i++) { desc[i].irq = i; desc[i].kstat_irqs = kstat_irqs_legacy[i]; @@ -153,7 +157,10 @@ int __init early_irq_init(void) struct irq_desc *irq_to_desc(unsigned int irq) { - return (irq < nr_irqs) ? irq_desc_ptrs[irq] : NULL; + if (irq_desc_ptrs && irq < nr_irqs) + return irq_desc_ptrs[irq]; + + return NULL; } struct irq_desc *irq_to_desc_alloc_cpu(unsigned int irq, int cpu) diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h index e6d0a43cc125..40416a81a0f5 100644 --- a/kernel/irq/internals.h +++ b/kernel/irq/internals.h @@ -16,7 +16,14 @@ extern int __irq_set_trigger(struct irq_desc *desc, unsigned int irq, extern struct lock_class_key irq_desc_lock_class; extern void init_kstat_irqs(struct irq_desc *desc, int cpu, int nr); extern spinlock_t sparse_irq_lock; + +#ifdef CONFIG_SPARSE_IRQ +/* irq_desc_ptrs allocated at boot time */ +extern struct irq_desc **irq_desc_ptrs; +#else +/* irq_desc_ptrs is a fixed size array */ extern struct irq_desc *irq_desc_ptrs[NR_IRQS]; +#endif #ifdef CONFIG_PROC_FS extern void register_irq_proc(unsigned int irq, struct irq_desc *desc); |