On 11/7/25 4:02 AM, Pasha Tatashin wrote:
On Fri, Nov 7, 2025 at 7:00 AM Pasha Tatashin pasha.tatashin@soleen.com wrote:
Hi, Pasha
In our previous discussion, we talked about counting the number of times the kernel is rebooted via kexec. At that time, you suggested adding a variable in debugfs to keep track of this count. However, since debugfs is now optional, where would be an appropriate place to store this variable?
It is an optional config and can still be enabled if the live update reboot number value needs to be accessed through debugfs. However, given that debugfs does not guarantee a stable interface, tooling should not be built to require these interfaces.
In the WIP LUO [1] I have, I pr_info() the live update number during boot and also store it in the incoming LUO FDT tree, which can also be accessed through this optional debugfs interface.
The pr_info message appears like this during boot: [ 0.000000] luo: Retrieved live update data, liveupdate number: 17
Pasha
Forgot to add link to WIP LUOv5: [1] https://github.com/soleen/linux/tree/luo/v5rc04
Thanks a lot. I’ve carefully read this commit: https://github.com/soleen/linux/commit/60205b9a95c319dc9965f119303a1d83f0ff0....
To be honest, I’d like to run some tests with who/luo, including the selftest for kho/luo. Could you please share the steps with me?
If the testing steps have already been documented somewhere, could you please share the link?
Best Regards,
Yanjun.Zhu