Re: [PATCH] hung_task: Increment the global counter immediately

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

On 2026/2/7 04:54, Aaron Tomlin wrote:
> On Wed, Feb 04, 2026 at 10:05:49AM -0800, Andrew Morton wrote:
>> On Wed, 4 Feb 2026 12:04:54 +0100 Petr Mladek <pmladek@suse.com> wrote:
>>
>>> A recent change allowed to reset the global counter of hung tasks using
>>> the sysctl interface. A potential race with the regular check has been
>>> solved by updating the global counter only once at the end of the check.
>>>
>>> However, the hung task check can take a significant amount of time,
>>> particularly when task information is being dumped to slow serial
>>> consoles. Some users monitor this global counter to trigger immediate
>>> migration of critical containers. Delaying the increment until the
>>> full check completes postpones these high-priority rescue operations.
>>>
>>> Update the global counter as soon as a hung task is detected. Since
>>> the value is read asynchronously, a relaxed atomic operation is
>>> sufficient.
>>>
>>> Reported-by: Lance Yang <lance.yang@linux.dev>
>>> Closes: https://lore.kernel.org/r/f239e00f-4282-408d-b172-0f9885f4b01b@linux.dev
>>> Signed-off-by: Petr Mladek <pmladek@suse.com>
>>> ---
>>> This is a followup patch for
>>> https://lore.kernel.org/r/20260125135848.3356585-1-atomlin@atomlin.com
>>>
>>> Note that I could not use commit IDs because the original
>>> patchset is not in a stable tree yet. In fact, it seems
>>> that it is not even in linux-next at the moment.
>>
>> Yes, I've gone into "fixes and trivial stuff only" mode, as we're at -rc8.
>>
>> Aaron, please incorporate Petr's fix into v8 and resend towards the end
>> of the merge window?
>>
>> Thanks.
> 
> Hi Andrew,
> 
> Absolutely.

Don't forget to credit Petr - just saying :)