kstat: modify kstat_irqs_legacy to be variable sized
Impact: reduce memory usage.
Allocate kstat_irqs_legacy based on nr_cpu_ids to deal with this
memory usage bump when NR_CPUS bumped from 128 to 4096:
8192 +253952 262144 +3100% kstat_irqs_legacy(.bss)
This is only when CONFIG_SPARSE_IRQS=y.
Signed-off-by: Mike Travis <travis@sgi.com>
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index ebba7a1..b39f32a 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -124,8 +124,7 @@
}
};
-/* FIXME: use bootmem alloc ...*/
-static unsigned int kstat_irqs_legacy[NR_IRQS_LEGACY][NR_CPUS];
+static unsigned int *kstat_irqs_legacy;
int __init early_irq_init(void)
{
@@ -144,9 +143,14 @@
/* allocate irq_desc_ptrs array based on nr_irqs */
irq_desc_ptrs = alloc_bootmem(nr_irqs * sizeof(void *));
+ /* allocate based on nr_cpu_ids */
+ /* FIXME: invert kstat_irgs, and it'd be a per_cpu_alloc'd thing */
+ kstat_irqs_legacy = alloc_bootmem(NR_IRQS_LEGACY * nr_cpu_ids *
+ sizeof(int));
+
for (i = 0; i < legacy_count; i++) {
desc[i].irq = i;
- desc[i].kstat_irqs = kstat_irqs_legacy[i];
+ desc[i].kstat_irqs = kstat_irqs_legacy + i * nr_cpu_ids;
lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
init_alloc_desc_masks(&desc[i], 0, true);
irq_desc_ptrs[i] = desc + i;