Re: [PATCH v8 0/2] hung_task: Improve warning budget handling and task reporting

[Andrew Morton]

On Tue,  4 Aug 2026 16:20:48 -0400 Aaron Tomlin <atomlin@xxxxxxxxxxx> wrote:

> The hung_task watchdog detects tasks stuck in TASK_UNINTERRUPTIBLE (D)
> state for longer than CONFIG_DEFAULT_HUNG_TASK_TIMEOUT seconds. To prevent
> log spam during system spikes, sysctl_hung_task_warnings enforces a budget
> on the number of logged warnings.
> 
> However, the current implementation has two major limitations:
> 
>     1. Permanent exhaustion of warning budget
> 
>        sysctl_hung_task_warnings is decremented directly when printing
>        warnings. Once this budget hits zero, no further warnings are
>        reported until an administrator manually updates the sysctl value or
>        reboots the system. Consequently, a single temporary hang episode
>        permanently blinds the kernel watchdog to any subsequent hung tasks
>        after system recovery.
> 
>     2. Total log suppression when budget is exhausted
> 
>        Once the warning budget reaches zero, hung_task_info() completely
>        suppresses all output, including the basic single-line alert. While
>        suppressing verbose stack dumps and lock debugging is desirable to
>        prevent dmesg flooding, hiding basic task alerts leaves
>        administrators entirely unaware that tasks are hanging.
> 
> This patch series resolves both limitations by decoupling the configured
> warning budget from the runtime warning counter, automatically resetting
> the budget when the system recovers, and keeping basic single-line hung
> task alerts visible.

Thanks.  A couple of concerns from AI review:
	https://sashiko.dev/#/patchset/20260804202050.262427-1-atomlin@xxxxxxxxxxx

Apologies if these were considered during review of previous
iterations.