Re: [PATCH v9 1/2] hung_task: Reset warning budget when problem gets resolved

[Lance Yang <lance.yang@linux.dev>]

On Fri, Aug 14, 2026 at 09:57:17AM -0400, Aaron Tomlin wrote:
>The sysctl hung_task_warnings currently holds both the configured warning
>limit and the remaining budget. Each detailed report decrements the
>sysctl, so once it reaches zero, the configured limit is lost and cannot
>be restored automatically.
>
>Keep sysctl hung_task_warnings unchanged and track the remaining budget
>in hung_task_warnings_printed. Reset the runtime budget via an atomic flag
>when a watchdog check sees no hung tasks or when userspace writes a new
>sysctl value.

Only sysctl writes go through reset_hung_task_warnings; no-hung case
reloads budget directly. Also worth spelling out why flag is there:
keeping runtime budget khungtaskd-owned. I'd write it as:

Keep sysctl_hung_task_warnings as the configured warning limit and make
khungtaskd the sole owner of the remaining budget. A check that finds no
hung tasks reloads the budget directly from the configured limit. A
successful sysctl write publishes an atomic reset request, which
khungtaskd consumes at the start of the next check.

No need to resend just for this, though. I think Andrew can fix that up
when applying.

>Suggested-by: Petr Mladek <pmladek@suse.com>
>Suggested-by: Lance Yang <lance.yang@linux.dev>
>Tested-by: Lance Yang <lance.yang@linux.dev>
>Signed-off-by: Aaron Tomlin <atomlin@atomlin.com>
>---

Nothing jumped out at me, thanks!

Reviewed-by: Lance Yang <lance.yang@linux.dev>