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authorYinghai Lu <yinghai@kernel.org>2009-01-12 17:39:24 -0800
committerMike Travis <travis@sgi.com>2009-01-12 17:39:24 -0800
commit4a046d1754ee6ebb6f399696805ed61ea0444d4c (patch)
tree9b9e8e63d9490aea4c2f06263ad541cb8115eb63 /arch/x86
parente65e49d0f3714f4a6a42f6f6a19926ba33fcda75 (diff)
x86: arch_probe_nr_irqs
Impact: save RAM with large NR_CPUS, get smaller nr_irqs Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Mike Travis <travis@sgi.com>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/include/asm/irq_vectors.h7
-rw-r--r--arch/x86/kernel/io_apic.c16
2 files changed, 18 insertions, 5 deletions
diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h
index 602361ad0e7..a16a2ab2b42 100644
--- a/arch/x86/include/asm/irq_vectors.h
+++ b/arch/x86/include/asm/irq_vectors.h
@@ -115,14 +115,11 @@
# endif
#else
-/* defined as a macro so nr_irqs = max_nr_irqs(nr_cpu_ids) can be used */
-# define max_nr_irqs(nr_cpus) \
- ((8 * nr_cpus) > (32 * MAX_IO_APICS) ? \
+# define NR_IRQS \
+ ((8 * NR_CPUS) > (32 * MAX_IO_APICS) ? \
(NR_VECTORS + (8 * NR_CPUS)) : \
(NR_VECTORS + (32 * MAX_IO_APICS))) \
-# define NR_IRQS max_nr_irqs(NR_CPUS)
-
#endif
#elif defined(CONFIG_X86_VOYAGER)
diff --git a/arch/x86/kernel/io_apic.c b/arch/x86/kernel/io_apic.c
index ae80638012d..157986916cd 100644
--- a/arch/x86/kernel/io_apic.c
+++ b/arch/x86/kernel/io_apic.c
@@ -3850,6 +3850,22 @@ void __init probe_nr_irqs_gsi(void)
nr_irqs_gsi = nr;
}
+#ifdef CONFIG_SPARSE_IRQ
+int __init arch_probe_nr_irqs(void)
+{
+ int nr;
+
+ nr = ((8 * nr_cpu_ids) > (32 * nr_ioapics) ?
+ (NR_VECTORS + (8 * nr_cpu_ids)) :
+ (NR_VECTORS + (32 * nr_ioapics)));
+
+ if (nr < nr_irqs && nr > nr_irqs_gsi)
+ nr_irqs = nr;
+
+ return 0;
+}
+#endif
+
/* --------------------------------------------------------------------------
ACPI-based IOAPIC Configuration
-------------------------------------------------------------------------- */