SoftDog: reboot message missed

SoftDog: reboot message missed

[Timofeev_Alexander]

Hi All,

I use 2.6.16.60 kernel. It's been compiled with CONFIG_WATCHDOG_NOWAYOUT
<http://lxr.linux.no/linux-bk+*/+code=CONFIG_WATCHDOG_NOWAYOUT> =false.
It reboots system silently. The reboot message does not appear in
/var/log/messages.
Syslog-ng config is correct.
I looked through the watchdog.c and found:

  93
<http://lxr.linux.no/linux-bk+*/drivers/char/watchdog/softdog.c#L93>
static void watchdog_fire
<http://lxr.linux.no/linux-bk+*/+code=watchdog_fire> (unsigned long data
<http://lxr.linux.no/linux-bk+*/+code=data> )
  94
<http://lxr.linux.no/linux-bk+*/drivers/char/watchdog/softdog.c#L94> {
  95
<http://lxr.linux.no/linux-bk+*/drivers/char/watchdog/softdog.c#L95>
if (soft_noboot <http://lxr.linux.no/linux-bk+*/+code=soft_noboot> )
  96
<http://lxr.linux.no/linux-bk+*/drivers/char/watchdog/softdog.c#L96>
printk <http://lxr.linux.no/linux-bk+*/+code=printk> (KERN_CRIT
<http://lxr.linux.no/linux-bk+*/+code=KERN_CRIT>  PFX
<http://lxr.linux.no/linux-bk+*/+code=PFX>  "Triggered - Reboot
ignored.\n");
  97
<http://lxr.linux.no/linux-bk+*/drivers/char/watchdog/softdog.c#L97>
else
  98
<http://lxr.linux.no/linux-bk+*/drivers/char/watchdog/softdog.c#L98>
{
  99
<http://lxr.linux.no/linux-bk+*/drivers/char/watchdog/softdog.c#L99>
printk <http://lxr.linux.no/linux-bk+*/+code=printk> (KERN_CRIT
<http://lxr.linux.no/linux-bk+*/+code=KERN_CRIT>  PFX
<http://lxr.linux.no/linux-bk+*/+code=PFX>  "Initiating system
reboot.\n");
 100
<http://lxr.linux.no/linux-bk+*/drivers/char/watchdog/softdog.c#L100>
machine_restart <http://lxr.linux.no/linux-bk+*/+code=machine_restart>
(NULL <http://lxr.linux.no/linux-bk+*/+code=NULL> );
 101
<http://lxr.linux.no/linux-bk+*/drivers/char/watchdog/softdog.c#L101>
printk <http://lxr.linux.no/linux-bk+*/+code=printk> (KERN_CRIT
<http://lxr.linux.no/linux-bk+*/+code=KERN_CRIT>  PFX
<http://lxr.linux.no/linux-bk+*/+code=PFX>  "Reboot didn't ?????\n");
 102
<http://lxr.linux.no/linux-bk+*/drivers/char/watchdog/softdog.c#L102>
}
 103
<http://lxr.linux.no/linux-bk+*/drivers/char/watchdog/softdog.c#L103> }


I suspect that system might be halted before printk buffer gets flushed.
Does anybody encounter such a behavior? Is there a workaround?

In fact I only need to know if the last reboot was caused by the timer.
Unfortunately the WDIOC_GETBOOTSTATUS
<http://lxr.linux.no/linux-bk+*/+code=WDIOC_GETBOOTSTATUS>  ioctl is not
implemented ( according to the watchdog.c:softdog_ioctl
<http://lxr.linux.no/linux-bk+*/+code=softdog_ioctl>  ).

 210
<http://lxr.linux.no/linux-bk+*/drivers/char/watchdog/softdog.c#L210>
case WDIOC_GETBOOTSTATUS
<http://lxr.linux.no/linux-bk+*/+code=WDIOC_GETBOOTSTATUS> :
 211
<http://lxr.linux.no/linux-bk+*/drivers/char/watchdog/softdog.c#L211>
return put_user <http://lxr.linux.no/linux-bk+*/+code=put_user> (0, p
<http://lxr.linux.no/linux-bk+*/+code=p> );


TIA


Alex T.

Re: SoftDog: reboot message missed

[Frans Pop]

Timofeev_Alexander@emc.com wrote:
> I suspect that system might be halted before printk buffer gets flushed.
> Does anybody encounter such a behavior?

Yes, I've seen the same for an emergency shutdown due to overheating 
(thermal zone "critical" trip point was reached). See my comment 2) in 
http://bugzilla.kernel.org/show_bug.cgi?id=13918#c12.

Cheers,
FJP