205 lines
6.1 KiB
C
205 lines
6.1 KiB
C
/*
|
|
* hangcheck-timer.c
|
|
*
|
|
* Driver for a little io fencing timer.
|
|
*
|
|
* Copyright (C) 2002, 2003 Oracle. All rights reserved.
|
|
*
|
|
* Author: Joel Becker <joel.becker@oracle.com>
|
|
*
|
|
* 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.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public
|
|
* License along with this program; if not, write to the
|
|
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
|
* Boston, MA 021110-1307, USA.
|
|
*/
|
|
|
|
/*
|
|
* The hangcheck-timer driver uses the TSC to catch delays that
|
|
* jiffies does not notice. A timer is set. When the timer fires, it
|
|
* checks whether it was delayed and if that delay exceeds a given
|
|
* margin of error. The hangcheck_tick module paramter takes the timer
|
|
* duration in seconds. The hangcheck_margin parameter defines the
|
|
* margin of error, in seconds. The defaults are 60 seconds for the
|
|
* timer and 180 seconds for the margin of error. IOW, a timer is set
|
|
* for 60 seconds. When the timer fires, the callback checks the
|
|
* actual duration that the timer waited. If the duration exceeds the
|
|
* alloted time and margin (here 60 + 180, or 240 seconds), the machine
|
|
* is restarted. A healthy machine will have the duration match the
|
|
* expected timeout very closely.
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/types.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/reboot.h>
|
|
#include <linux/smp_lock.h>
|
|
#include <linux/init.h>
|
|
#include <linux/delay.h>
|
|
#include <asm/uaccess.h>
|
|
#include <linux/sysrq.h>
|
|
|
|
|
|
#define VERSION_STR "0.9.0"
|
|
|
|
#define DEFAULT_IOFENCE_MARGIN 60 /* Default fudge factor, in seconds */
|
|
#define DEFAULT_IOFENCE_TICK 180 /* Default timer timeout, in seconds */
|
|
|
|
static int hangcheck_tick = DEFAULT_IOFENCE_TICK;
|
|
static int hangcheck_margin = DEFAULT_IOFENCE_MARGIN;
|
|
static int hangcheck_reboot; /* Defaults to not reboot */
|
|
static int hangcheck_dump_tasks; /* Defaults to not dumping SysRQ T */
|
|
|
|
/* options - modular */
|
|
module_param(hangcheck_tick, int, 0);
|
|
MODULE_PARM_DESC(hangcheck_tick, "Timer delay.");
|
|
module_param(hangcheck_margin, int, 0);
|
|
MODULE_PARM_DESC(hangcheck_margin, "If the hangcheck timer has been delayed more than hangcheck_margin seconds, the driver will fire.");
|
|
module_param(hangcheck_reboot, int, 0);
|
|
MODULE_PARM_DESC(hangcheck_reboot, "If nonzero, the machine will reboot when the timer margin is exceeded.");
|
|
module_param(hangcheck_dump_tasks, int, 0);
|
|
MODULE_PARM_DESC(hangcheck_dump_tasks, "If nonzero, the machine will dump the system task state when the timer margin is exceeded.");
|
|
|
|
MODULE_AUTHOR("Oracle");
|
|
MODULE_DESCRIPTION("Hangcheck-timer detects when the system has gone out to lunch past a certain margin.");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_VERSION(VERSION_STR);
|
|
|
|
/* options - nonmodular */
|
|
#ifndef MODULE
|
|
|
|
static int __init hangcheck_parse_tick(char *str)
|
|
{
|
|
int par;
|
|
if (get_option(&str,&par))
|
|
hangcheck_tick = par;
|
|
return 1;
|
|
}
|
|
|
|
static int __init hangcheck_parse_margin(char *str)
|
|
{
|
|
int par;
|
|
if (get_option(&str,&par))
|
|
hangcheck_margin = par;
|
|
return 1;
|
|
}
|
|
|
|
static int __init hangcheck_parse_reboot(char *str)
|
|
{
|
|
int par;
|
|
if (get_option(&str,&par))
|
|
hangcheck_reboot = par;
|
|
return 1;
|
|
}
|
|
|
|
static int __init hangcheck_parse_dump_tasks(char *str)
|
|
{
|
|
int par;
|
|
if (get_option(&str,&par))
|
|
hangcheck_dump_tasks = par;
|
|
return 1;
|
|
}
|
|
|
|
__setup("hcheck_tick", hangcheck_parse_tick);
|
|
__setup("hcheck_margin", hangcheck_parse_margin);
|
|
__setup("hcheck_reboot", hangcheck_parse_reboot);
|
|
__setup("hcheck_dump_tasks", hangcheck_parse_dump_tasks);
|
|
#endif /* not MODULE */
|
|
|
|
#if defined(CONFIG_X86_64) || defined(CONFIG_S390)
|
|
# define HAVE_MONOTONIC
|
|
# define TIMER_FREQ 1000000000ULL
|
|
#elif defined(CONFIG_IA64)
|
|
# define TIMER_FREQ ((unsigned long long)local_cpu_data->itc_freq)
|
|
#else
|
|
# define TIMER_FREQ (HZ*loops_per_jiffy)
|
|
#endif
|
|
|
|
#ifdef HAVE_MONOTONIC
|
|
extern unsigned long long monotonic_clock(void);
|
|
#else
|
|
static inline unsigned long long monotonic_clock(void)
|
|
{
|
|
return get_cycles();
|
|
}
|
|
#endif /* HAVE_MONOTONIC */
|
|
|
|
|
|
/* Last time scheduled */
|
|
static unsigned long long hangcheck_tsc, hangcheck_tsc_margin;
|
|
|
|
static void hangcheck_fire(unsigned long);
|
|
|
|
static DEFINE_TIMER(hangcheck_ticktock, hangcheck_fire, 0, 0);
|
|
|
|
|
|
static void hangcheck_fire(unsigned long data)
|
|
{
|
|
unsigned long long cur_tsc, tsc_diff;
|
|
|
|
cur_tsc = monotonic_clock();
|
|
|
|
if (cur_tsc > hangcheck_tsc)
|
|
tsc_diff = cur_tsc - hangcheck_tsc;
|
|
else
|
|
tsc_diff = (cur_tsc + (~0ULL - hangcheck_tsc)); /* or something */
|
|
|
|
if (tsc_diff > hangcheck_tsc_margin) {
|
|
if (hangcheck_dump_tasks) {
|
|
printk(KERN_CRIT "Hangcheck: Task state:\n");
|
|
#ifdef CONFIG_MAGIC_SYSRQ
|
|
handle_sysrq('t', NULL, NULL);
|
|
#endif /* CONFIG_MAGIC_SYSRQ */
|
|
}
|
|
if (hangcheck_reboot) {
|
|
printk(KERN_CRIT "Hangcheck: hangcheck is restarting the machine.\n");
|
|
emergency_restart();
|
|
} else {
|
|
printk(KERN_CRIT "Hangcheck: hangcheck value past margin!\n");
|
|
}
|
|
}
|
|
mod_timer(&hangcheck_ticktock, jiffies + (hangcheck_tick*HZ));
|
|
hangcheck_tsc = monotonic_clock();
|
|
}
|
|
|
|
|
|
static int __init hangcheck_init(void)
|
|
{
|
|
printk("Hangcheck: starting hangcheck timer %s (tick is %d seconds, margin is %d seconds).\n",
|
|
VERSION_STR, hangcheck_tick, hangcheck_margin);
|
|
#if defined (HAVE_MONOTONIC)
|
|
printk("Hangcheck: Using monotonic_clock().\n");
|
|
#else
|
|
printk("Hangcheck: Using get_cycles().\n");
|
|
#endif /* HAVE_MONOTONIC */
|
|
hangcheck_tsc_margin =
|
|
(unsigned long long)(hangcheck_margin + hangcheck_tick);
|
|
hangcheck_tsc_margin *= (unsigned long long)TIMER_FREQ;
|
|
|
|
hangcheck_tsc = monotonic_clock();
|
|
mod_timer(&hangcheck_ticktock, jiffies + (hangcheck_tick*HZ));
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
static void __exit hangcheck_exit(void)
|
|
{
|
|
del_timer_sync(&hangcheck_ticktock);
|
|
printk("Hangcheck: Stopped hangcheck timer.\n");
|
|
}
|
|
|
|
module_init(hangcheck_init);
|
|
module_exit(hangcheck_exit);
|