Messages in this thread Patch in this message | | | Date | Mon, 24 Mar 2008 09:31:00 -0500 (CDT) | From | Alan Mayer <> | Subject | [PATCH] x86_64: resize NR_IRQS for large machines |
| |
Subject: [PATCH] x86_64: resize NR_IRQS for large machines
From: Alan Mayer <ajm@sgi.com>
On machines with very large numbers of cpus, tables that are dimensioned by NR_IRQS get very large, especially the irq_desc table. They are also very sparsely used. When the cpu count is > MAX_IO_APICS, use MAX_IO_APICS to set NR_IRQS, otherwise use NR_CPUS.
Signed-off-by: Alan Mayer <ajm@sgi.com>
Reviewed-by: Christoph Lameter <clameter@sgi.com>
---
Index: v2.6.25-rc6/include/asm-x86/irq_64.h =================================================================== --- v2.6.25-rc6.orig/include/asm-x86/irq_64.h 2008-03-19 16:52:52.000000000 -0500 +++ v2.6.25-rc6/include/asm-x86/irq_64.h 2008-03-20 16:46:51.000000000 -0500 @@ -10,6 +10,10 @@ * <tomsoft@informatik.tu-chemnitz.de> */ +#if !defined(MAX_IO_APICS) +#include <asm/apicdef.h> +#endif + #define TIMER_IRQ 0 /* @@ -31,7 +35,11 @@ #define FIRST_SYSTEM_VECTOR 0xef /* duplicated in hw_irq.h */ -#define NR_IRQS (NR_VECTORS + (32 *NR_CPUS)) +#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 #define NR_IRQ_VECTORS NR_IRQS static __inline__ int irq_canonicalize(int irq) Index: v2.6.25-rc6/include/linux/kernel_stat.h =================================================================== --- v2.6.25-rc6.orig/include/linux/kernel_stat.h 2008-03-19 16:53:00.000000000 -0500 +++ v2.6.25-rc6/include/linux/kernel_stat.h 2008-03-20 11:12:27.000000000 -0500 @@ -1,11 +1,11 @@ #ifndef _LINUX_KERNEL_STAT_H #define _LINUX_KERNEL_STAT_H -#include <asm/irq.h> #include <linux/smp.h> #include <linux/threads.h> #include <linux/percpu.h> #include <linux/cpumask.h> +#include <asm/irq.h> #include <asm/cputime.h> /*
| |