software watchdog

software watchdog

[gspujar]

Hi,
I am using software watchdog in my application. Is there any way to ensure that
watchdog continues its
job even after the process that opens the watchdog device crashes or teminates ?

Thanks in advance
Girish

Re: software watchdog

[Alberto Bertogli]

On Fri, Nov 02, 2001 at 11:38:47AM +0530, gspujar@hss.hns.com wrote:
> Hi,
> I am using software watchdog in my application. Is there any way to ensure that
> watchdog continues its
> job even after the process that opens the watchdog device crashes or teminates ?
> 

I think CONFIG_WATCHDOG_NOWAYOUT is exactly what you want.
You find it just where you enabled your watchdog.

		Alberto

Re: software watchdog

[Oliver Xymoron]

On Tue, 11 Dec 2001, Russell King wrote:

> On Tue, Dec 11, 2001 at 04:26:07PM +0530, gspujar@hss.hns.com wrote:
> > Why is that the printk output not going to syslog although  I have entry in
> > /etc/syslog.conf
> >
> > kern.crit                       /var/log/pbsc.log
> > even after I remove the mdelay call.
>
> The machine reboots before syslog gets to run.
>
> What happens is:
>
> 	printk();
> 	reboot();
>
> During that period, syslog is unable to run, and therefore is unable to
> write the log message to disk.
>
> > Does it mean that without using "testing" mode ( I cannot beacuse I need a
> > reboot) it is not possible to get log  ?
>
> I suppose you could modify softdog to delay the reboot using it's timer
> (the timer fires the first time, you check data to see if it's non-zero.
> If it's not, increment watchdog_ticktock.data, and set the watchdog to
> timeout in 5 seconds, return).

Silly. The whole point of watchdog is to reboot a wedged machine. The
reason it's firing is presumably because the userspace watchdog
daemon didn't get a chance to touch the device, so odds that syslog would
get a chance to run are pretty slim.

If you really need a log message, get a serial console.

-- 
 "Love the dolphins," she advised him. "Write by W.A.S.T.E.."

Re: software watchdog

[Russell King]

On Tue, Dec 11, 2001 at 04:26:07PM +0530, gspujar@hss.hns.com wrote:
> Why is that the printk output not going to syslog although  I have entry in
> /etc/syslog.conf
> 
> kern.crit                       /var/log/pbsc.log
> even after I remove the mdelay call.

The machine reboots before syslog gets to run.

What happens is:

	printk();
	reboot();

During that period, syslog is unable to run, and therefore is unable to
write the log message to disk.

> Does it mean that without using "testing" mode ( I cannot beacuse I need a
> reboot) it is not possible to get log  ?

I suppose you could modify softdog to delay the reboot using it's timer
(the timer fires the first time, you check data to see if it's non-zero.
If it's not, increment watchdog_ticktock.data, and set the watchdog to
timeout in 5 seconds, return).

You should probably prevent softdog_write updating the timer if the
data field is non-zero, so once you don't change the behaviour; this
is of course dependent on your test case.

--
Russell King (rmk@arm.linux.org.uk)                The developer of ARM Linux
             http://www.arm.linux.org.uk/personal/aboutme.html

Re: software watchdog

[gspujar]

Hi,
Why is that the printk output not going to syslog although  I have entry in
/etc/syslog.conf

kern.crit                       /var/log/pbsc.log
even after I remove the mdelay call.

Where as I am getting a log from another driver I am using. It also uses printk.

Does it mean that without using "testing" mode ( I cannot beacuse I need a
reboot) it is
not possible to get log  ?

Thanks in advance
Girish





Russell King <rmk@arm.linux.org.uk> on 12/11/2001 03:38:03 PM

To:   Girish S Pujar/HSS@HSS
cc:   linux-kernel@vger.kernel.org, Atul Chowdhry/HSS@HSS

Subject:  Re: software watchdog




On Tue, Dec 11, 2001 at 01:33:04PM +0530, gspujar@hss.hns.com wrote:
> >>>printk(KERN_CRIT "SOFTDOG: Initiating system reboot.\n"); prints the
> message on the console.
>
> I put a delay of 5secs with mdelay, and I can see the message on the console.
> I wanted the message as a syslog,

In order to log this message to syslog, you need to allow the syslog
process to run.  If you're using a uniprocessor machine, using mdelay()
doesn't allow syslog to run during this time.

Softdog has a "testing" mode, which can be enabled by defining
ONLY_TESTING.  This disables the automatic reboot, but the system
will log the timeout message.

--
Russell King (rmk@arm.linux.org.uk)                The developer of ARM Linux
             http://www.arm.linux.org.uk/personal/aboutme.html

Re: software watchdog

[Russell King]

On Tue, Dec 11, 2001 at 01:33:04PM +0530, gspujar@hss.hns.com wrote:
> >>>printk(KERN_CRIT "SOFTDOG: Initiating system reboot.\n"); prints the
> message on the console.
> 
> I put a delay of 5secs with mdelay, and I can see the message on the console.
> I wanted the message as a syslog,

In order to log this message to syslog, you need to allow the syslog
process to run.  If you're using a uniprocessor machine, using mdelay()
doesn't allow syslog to run during this time.

Softdog has a "testing" mode, which can be enabled by defining
ONLY_TESTING.  This disables the automatic reboot, but the system
will log the timeout message.

--
Russell King (rmk@arm.linux.org.uk)                The developer of ARM Linux
             http://www.arm.linux.org.uk/personal/aboutme.html

Re: software watchdog

[J Sloan]

gspujar@hss.hns.com wrote:

> Hi all,
>
> I am using software watchdog in my application.  When the watchdog reboots the
> system,
>
> >>>printk(KERN_CRIT "SOFTDOG: Initiating system reboot.\n"); prints the message
> on the console.
>
> I put a delay of 5secs with mdelay, and I can see the message on the console.
> I wanted the message as a syslog,
>
> so I added         kern.crit in /etc/syslog.conf file.,
> But I am not getting the above message in the log file.
> Can any one help me with this ????

Send the message to "*" instead of /var/log/messages

That, and/or arrange to do a sync before reboot.

I'm sure there are other ways as well...

cu

jjs

software watchdog

[gspujar]

Hi all,

I am using software watchdog in my application.  When the watchdog reboots the
system,

>>>printk(KERN_CRIT "SOFTDOG: Initiating system reboot.\n"); prints the message
on the console.

I put a delay of 5secs with mdelay, and I can see the message on the console.
I wanted the message as a syslog,

so I added         kern.crit in /etc/syslog.conf file.,
But I am not getting the above message in the log file.
Can any one help me with this ????

Thanks
Girish