From 0fa0ebbf15addc1be8f73325d809c8547a9de304 Mon Sep 17 00:00:00 2001
From: Mike Travis <travis@sgi.com>
Date: Sat, 10 Jan 2009 22:24:06 -0800
Subject: 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>
---
kernel/irq/internals.h | 7 +++++++
1 file changed, 7 insertions(+)
(limited to 'kernel/irq/internals.h')
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index e6d0a43cc12..40416a81a0f 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);
--
cgit v1.2.3-70-g09d2