Re: mm/memory-failure tracepoint change breaks userspace rasdaemon

[Steven Rostedt]

On June 5, 2026 4:52:28 AM EDT, "David Hildenbrand (Arm)" <david@xxxxxxxxxx> wrote:
>On 6/3/26 21:31, Steven Rostedt wrote:
>> On Wed, 3 Jun 2026 21:13:30 +0200
>> "David Hildenbrand (Arm)" <david@xxxxxxxxxx> wrote:
>> 
>>> Thanks, that makes sense!
>>>
>>> So, would it be fair to say that, in general, what's exposed through
>>>
>>> 	/sys/kernel/tracing/events/
>>>
>>> is stable ABI?
>> 
>> It's only stable if something depends on it. It changes all the time.
>> It's only when someone complains about it that it becomes "stable"!
>
>Heh, so we only know that it's stable when we break it ...
>
>Let me figure out how to document that.
>

Yep. That's basically Linus's rule. He even said we break user space API all the time. What we don't allow is to break actual user space. The problem is that you can break user space by fixing an API without knowing something depended on the bug.