Re: [PATCH] hugetlb: add cond_resched() to __unmap_hugepage_range()

["David Hildenbrand (Arm)" <david@kernel.org>]

On 8/18/26 20:55, Andrew Morton wrote:
> On Tue, 18 Aug 2026 20:21:37 +0200 "David Hildenbrand (Arm)" <david@kernel.org> wrote:
> 
>>>
>>> That's pretty bad behavior and we might want to fix it in earlier
>>> kernels.  Is PREEMPT_NONE effectively dead in 6.18.x and its
>>> existing users?
>>>
>>> If yes, we do want to fix older kernels then we should merge this.
>>>
>>
>> Okay, but that would be stable-only fixes?
> 
> Not understanding.
> 
> Maybe you refer to adding a patch to -stable but not to -linus?  That's
> against the -stable rules
> (Documentation/process/stable-kernel-rules.rst).

It's tricky: if a problem only exists in stable (there is nothing to fix in
Linus' tree), then a stable-only fix is acceptable.

Otherwise we'd have to route unnecessary churn through upstream just for it to
reach stable, which doesn't make any sense.

When sending a stable patch, it should document how this is only a stable
problem and why no corresponding upstream fix is required (or how the actual fix
for upstream is actually deprecating the relevant config).

-- 
Cheers,

David