Re: [syzbot] [mm?] WARNING in deferred_split_folio

Lance Yang
2026-04-01T11:41:20Z

On 2026/4/1 19:38, David Hildenbrand (Arm) wrote:
> On 4/1/26 13:34, Lance Yang wrote:
>>
>> On Wed, Apr 01, 2026 at 01:22:58PM +0200, David Hildenbrand (Arm) wrote:
>>> On 4/1/26 13:20, Lance Yang wrote:
>>>>
>>>>
>>>> Ouch, you're right, I was wrong - the trylock drop is a pre-existing
>>>> issue, not caused by the reorder ;)
>>>>
>>>>
>>>> Nice, LGTM!
>>>>
>>>> Given that the "trylock -> drop" behavior seems to exist already today,
>>>> do you think it's worth fixing that together with the reorder?
>>>
>>> I'd do it in a single shot if possible.
>>
>> ACK.
>>
>>> Can you craft something? (cc stable etc)
>>
>> certainly, will do! But commit[1] ("mm: migrate: requeue destination
>> folio on deferred split queue") is only in mm-stable now, not yet
>> upstream/stable ...
>
> It's tricky. The original commit will be backported to stable kernels,
> so we want also the fix to be backported to the same stable kernels.
>
> The commit id in mm-stable is "stable" now.

Emm... Not a big deal, I guess. We can always submit a stable backport
once that fix gets merged into stable :D