[PATCH] doc: watchdog: Add an usage note on hpwdt with hp-asrd

[PATCH] doc: watchdog: Add an usage note on hpwdt with hp-asrd

[Masanari Iida]

An agent software called hp-asrd from Hewlett Packard
updates same iLO watchdog timer as hpwdt does update.
So they can not be uses simultaneously.
Add this usage note in hpwdt.txt.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
---
 Documentation/watchdog/hpwdt.txt | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Documentation/watchdog/hpwdt.txt b/Documentation/watchdog/hpwdt.txt
index 9488078..719c38d 100644
--- a/Documentation/watchdog/hpwdt.txt
+++ b/Documentation/watchdog/hpwdt.txt
@@ -89,7 +89,8 @@ Last reviewed: 06/02/2009
 
 	Hypertransport/CSI Error       31h
 
-
+hpwdt can not work as expected if hp-asrd is running simultaneously.
+Because both hpwdt and hp-asrd update same iLO watchdog timer.
 
  -- Tom Mingarelli
     (thomas.mingarelli@hp.com)
-- 
2.0.0.rc0.38.g1697bf3

Re: [PATCH] doc: watchdog: Add an usage note on hpwdt with hp-asrd

[Guenter Roeck]

On 04/25/2014 03:52 AM, Masanari Iida wrote:
> An agent software called hp-asrd from Hewlett Packard
> updates same iLO watchdog timer as hpwdt does update.
> So they can not be uses simultaneously.
> Add this usage note in hpwdt.txt.
>
> Signed-off-by: Masanari Iida <standby24x7@gmail.com>
> ---
>   Documentation/watchdog/hpwdt.txt | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/watchdog/hpwdt.txt b/Documentation/watchdog/hpwdt.txt
> index 9488078..719c38d 100644
> --- a/Documentation/watchdog/hpwdt.txt
> +++ b/Documentation/watchdog/hpwdt.txt
> @@ -89,7 +89,8 @@ Last reviewed: 06/02/2009
>
>   	Hypertransport/CSI Error       31h
>
> -
> +hpwdt can not work as expected if hp-asrd is running simultaneously.
> +Because both hpwdt and hp-asrd update same iLO watchdog timer.
>

How about adding a note here explaining that hp-asrd is a user space application
from HP (assuming that is what it is) ?

Guenter

RE: [PATCH] doc: watchdog: Add an usage note on hpwdt with hp-asrd

[Mingarelli, Thomas]

Yes I need to review this before it being submitted. Some confusion here.

-----Original Message-----
From: Guenter Roeck [mailto:linux@roeck-us.net] 
Sent: Friday, April 25, 2014 8:03 AM
To: Masanari Iida; wim@iguana.be; linux-watchdog@vger.kernel.org; Mingarelli, Thomas; linux-kernel@vger.kernel.org
Subject: Re: [PATCH] doc: watchdog: Add an usage note on hpwdt with hp-asrd

On 04/25/2014 03:52 AM, Masanari Iida wrote:
> An agent software called hp-asrd from Hewlett Packard updates same iLO 
> watchdog timer as hpwdt does update.
> So they can not be uses simultaneously.
> Add this usage note in hpwdt.txt.
>
> Signed-off-by: Masanari Iida <standby24x7@gmail.com>
> ---
>   Documentation/watchdog/hpwdt.txt | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/watchdog/hpwdt.txt 
> b/Documentation/watchdog/hpwdt.txt
> index 9488078..719c38d 100644
> --- a/Documentation/watchdog/hpwdt.txt
> +++ b/Documentation/watchdog/hpwdt.txt
> @@ -89,7 +89,8 @@ Last reviewed: 06/02/2009
>
>   	Hypertransport/CSI Error       31h
>
> -
> +hpwdt can not work as expected if hp-asrd is running simultaneously.
> +Because both hpwdt and hp-asrd update same iLO watchdog timer.
>

How about adding a note here explaining that hp-asrd is a user space application from HP (assuming that is what it is) ?

Guenter

Re: [PATCH] doc: watchdog: Add an usage note on hpwdt with hp-asrd

[Masanari Iida]

I have encountered a symptom that I could not use hpwdt
with hp-asrd on BL460c Gen8 + RHEL6.4.

How to reproduce
(1)  Start hp-asrd  with ASR timeout as 600 seconds
(2)  Load hpwdt  with soft_margin as 30 seconds.
(3)  # echo 1 > /dev/watchdog  and wait 30 sec to reboot.

Actual Result
No reboot happen.

(4)  Stop hp-asrd
(5)  # echo 1 > /dev/watchdog  and wait 30sec to reboot

Actual Result
Reboot after 30 sec.

And my colleague wrote a small tool to send an ioctl to
/dev/watchdog to get  WDIOC_GETTIMELEFT.

(6)  Run a tool to monitor time left.
(7)  # echo 1 >  /dev/watchdog
(8)  Before 30sec timeout expire, start  hp-asrd .

Result

time left=22
time left=20
time left=19
time left=19
time left=18
time left=17
time left=16
time left=14
time left=13
time left=13
time left=12
time left=599　　<= The time when hp-asrd started
time left=599
time left=599
time left=599

So this is the reason why hp-asrd and hpwdt update the same timer.
So I conclude they can not run simultaneously.

Masanari
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Re: [PATCH] doc: watchdog: Add an usage note on hpwdt with hp-asrd

[Randy Dunlap]

On 04/25/14 03:52, Masanari Iida wrote:
> An agent software called hp-asrd from Hewlett Packard
> updates same iLO watchdog timer as hpwdt does update.
> So they can not be uses simultaneously.
> Add this usage note in hpwdt.txt.
> 
> Signed-off-by: Masanari Iida <standby24x7@gmail.com>
> ---
>  Documentation/watchdog/hpwdt.txt | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/watchdog/hpwdt.txt b/Documentation/watchdog/hpwdt.txt
> index 9488078..719c38d 100644
> --- a/Documentation/watchdog/hpwdt.txt
> +++ b/Documentation/watchdog/hpwdt.txt
> @@ -89,7 +89,8 @@ Last reviewed: 06/02/2009
>  
>  	Hypertransport/CSI Error       31h
>  
> -
> +hpwdt can not work as expected if hp-asrd is running simultaneously.

         cannot                                                       ,

> +Because both hpwdt and hp-asrd update same iLO watchdog timer.

   because                        update the same

>  
>   -- Tom Mingarelli
>      (thomas.mingarelli@hp.com)
> 


-- 
~Randy