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authorYinghai Lu <yinghai@kernel.org>2008-12-05 18:58:31 -0800
committerIngo Molnar <mingo@elte.hu>2008-12-08 14:31:51 +0100
commit0b8f1efad30bd58f89961b82dfe68b9edf8fd2ac (patch)
tree239251bad791fd60af8c0f2ba365b7188395c83f /arch/x86/include/asm/irq_vectors.h
parent218d11a8b071b23b76c484fd5f72a4fe3306801e (diff)
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 <yinghai@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/include/asm/irq_vectors.h')
-rw-r--r--arch/x86/include/asm/irq_vectors.h9
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h
index 0005adb0f94..bb6b69a6b12 100644
--- a/arch/x86/include/asm/irq_vectors.h
+++ b/arch/x86/include/asm/irq_vectors.h
@@ -102,11 +102,20 @@
#define invalid_vm86_irq(irq) ((irq) < 3 || (irq) > 15)
#if defined(CONFIG_X86_IO_APIC) && !defined(CONFIG_X86_VOYAGER)
+
+#ifndef CONFIG_SPARSE_IRQ
# if NR_CPUS < MAX_IO_APICS
# define NR_IRQS (NR_VECTORS + (32 * NR_CPUS))
# else
# define NR_IRQS (NR_VECTORS + (32 * MAX_IO_APICS))
# endif
+#else
+# if (8 * NR_CPUS) > (32 * MAX_IO_APICS)
+# define NR_IRQS (NR_VECTORS + (8 * NR_CPUS))
+# else
+# define NR_IRQS (NR_VECTORS + (32 * MAX_IO_APICS))
+# endif
+#endif
#elif defined(CONFIG_X86_VOYAGER)