CELF Project Proposal: Create a watchdog framework for the Linux kernel

Wolfram Sang <w.sang@...>

Proposer: Wolfram Sang

Summary: Create a watchdog framework for the Linux kernel

Description: The watchdog API of the Linux kernel is documented and used for
years. Yet, there is no abstraction for its common functionality (open, write,
ioctl, close), so every watchdog driver has to implement those methods on its
own. In addition to the vast amount of code duplication in the kernel source,
this is also error-prone as there are subtle corner-cases in handling the
watchdog and the userspace-input correctly. Although there is code review for
new drivers, it seems very desirable to improve the situation as a whole.

There have been two approaches for a generic watchdog framework, one from Alan
Cox and one from Wim van Sebroeck, the current watchdog maintainer. Sadly,
nothing from those have made it to mainline so far. This is a bit surprising;
although watchdogs are usually rather simple devices, they are crucial for the
stability concept of an enormous number of devices. The benefit of this
proposal is to have a rock-solid, well maintainable and trustworthy watchdog
framework, which makes writing new drivers faster and less error-prone.

Related work:

* Proposal by Alan Cox:

* Proposal by Wim van Sebroeck:

My estimation would be 4 weeks of development and testing

Pengutronix e.K. | Wolfram Sang |
Industrial Linux Solutions | http://www.pengutronix.de/ |

Tim Bird <tim.bird@...>

Wolfram Sang wrote:
Summary: Create a watchdog framework for the Linux kernel
Interesting. I've created a page for this proposal at:

-- Tim

Tim Bird
Architecture Group Chair, CE Linux Forum
Senior Staff Engineer, Sony Corporation of America