HZ、CONFIG_HZ 和 jiffies 变量在 linux内核源码中定义的位置

HZ  和 CONFIG_HZ 宏定义的位置：

实际上在 linux-2.6.x/include/asm/param.h  定义了HZ的值：

 

/*
 *  arch/arm/include/asm/param.h
 *
 *  Copyright (C) 1995-1999 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#ifndef __ASM_PARAM_H
#define __ASM_PARAM_H

 

#ifdef __KERNEL__

# define HZ     CONFIG_HZ                   /* Internal kernel timer frequency */
# define USER_HZ    100                     /* User interfaces are in "ticks" */
# define CLOCKS_PER_SEC (USER_HZ)              /* like times() */

#else

# define HZ     100

#endif

 

#define EXEC_PAGESIZE   4096

#ifndef NOGROUP
#define NOGROUP         (-1)
#endif

/* max length of hostname */
#define MAXHOSTNAMELEN  64

#endif

 

 

CONFIG_HZ的值可以在make menuconfig时设置，表示每秒钟定时器发生中断的次数，默认值是250。