Check if the TSC source is stable otherwise fail registration.
Signed-off-by: Michael Trimarchi <[email protected]>
---
diff --git a/drivers/char/hangcheck-timer.c b/drivers/char/hangcheck-timer.c
index 712d9f2..910a77a 100644
--- a/drivers/char/hangcheck-timer.c
+++ b/drivers/char/hangcheck-timer.c
@@ -10,12 +10,12 @@
* 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,
@@ -64,14 +64,18 @@ static int hangcheck_dump_tasks; /* Defaults to not dumping SysRQ T */
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_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_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_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_DESCRIPTION("Hangcheck-timer detects when the system has gone"
+ " out to lunch past a certain margin.");
MODULE_LICENSE("GPL");
MODULE_VERSION(VERSION_STR);
@@ -81,7 +85,7 @@ MODULE_VERSION(VERSION_STR);
static int __init hangcheck_parse_tick(char *str)
{
int par;
- if (get_option(&str,&par))
+ if (get_option(&str, &par))
hangcheck_tick = par;
return 1;
}
@@ -89,7 +93,7 @@ static int __init hangcheck_parse_tick(char *str)
static int __init hangcheck_parse_margin(char *str)
{
int par;
- if (get_option(&str,&par))
+ if (get_option(&str, &par))
hangcheck_margin = par;
return 1;
}
@@ -97,7 +101,7 @@ static int __init hangcheck_parse_margin(char *str)
static int __init hangcheck_parse_reboot(char *str)
{
int par;
- if (get_option(&str,&par))
+ if (get_option(&str, &par))
hangcheck_reboot = par;
return 1;
}
@@ -105,7 +109,7 @@ static int __init hangcheck_parse_reboot(char *str)
static int __init hangcheck_parse_dump_tasks(char *str)
{
int par;
- if (get_option(&str,&par))
+ if (get_option(&str, &par))
hangcheck_dump_tasks = par;
return 1;
}
@@ -151,8 +155,10 @@ static void hangcheck_fire(unsigned long data)
if (cur_tsc > hangcheck_tsc)
tsc_diff = cur_tsc - hangcheck_tsc;
- else
- tsc_diff = (cur_tsc + (~0ULL - hangcheck_tsc)); /* or something */
+ else {
+ /* or samenthing */
+ tsc_diff = (cur_tsc + (~0ULL - hangcheck_tsc));
+ }
if (tsc_diff > hangcheck_tsc_margin) {
if (hangcheck_dump_tasks) {
@@ -172,15 +178,21 @@ static void hangcheck_fire(unsigned long data)
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",
+ printk(KERN_INFO "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");
+#if defined(HAVE_MONOTONIC)
+ printk(KERN_INFO "Hangcheck: Using monotonic_clock().\n");
#else
- printk("Hangcheck: Using get_cycles().\n");
+ if (!check_tsc_unstable())
+ printk(KERN_INFO "Hangcheck: Using get_cycles().\n");
+ else {
+ printk(KERN_ERR "Handcheck: Failed to register"
+ " (Unstable TSC).\n");
+ return -ENODEV;
+ }
#endif /* HAVE_MONOTONIC */
hangcheck_tsc_margin =
(unsigned long long)(hangcheck_margin + hangcheck_tick);
@@ -196,7 +208,7 @@ static int __init hangcheck_init(void)
static void __exit hangcheck_exit(void)
{
del_timer_sync(&hangcheck_ticktock);
- printk("Hangcheck: Stopped hangcheck timer.\n");
+ printk(KERN_INFO "Hangcheck: Stopped hangcheck timer.\n");
}
module_init(hangcheck_init);
On Thu, Nov 06, 2008 at 11:37:28PM +0100, Michael Trimarchi wrote:
> Check if the TSC source is stable otherwise fail registration.
Good idea.
> @@ -151,8 +155,10 @@ static void hangcheck_fire(unsigned long data)
>
> if (cur_tsc > hangcheck_tsc)
> tsc_diff = cur_tsc - hangcheck_tsc;
> - else
> - tsc_diff = (cur_tsc + (~0ULL - hangcheck_tsc)); /* or something */
> + else {
> + /* or samenthing */
> + tsc_diff = (cur_tsc + (~0ULL - hangcheck_tsc));
> + }
This hunk isn't any good. The comment spelling is messed up,
and really you can just remove the "or something".
Joel
--
"There is no sincerer love than the love of food."
- George Bernard Shaw
Joel Becker
Principal Software Developer
Oracle
E-mail: [email protected]
Phone: (650) 506-8127