Re: [PATCH v3 1/1] khugepaged: fix readahead lock inversion in collapse_file()

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

On 2026/10/26 19:26, David Hildenbrand (Arm) wrote:
> On 10/18/26 04:47, Baolin Wang wrote:
>>
>>
>> On 10/17/26 3:41 PM, Lance Yang wrote:
>>>
>>>
>>> On 2026/10/17 13:43, Baolin Wang wrote:
>>>>
>>>>
>>>>
>>>> OK.
>>>>
>>>>
>>>> Sounds good.
>>>>
>>>>
>>>> But why not add RA logic in collapse_pmd(), as we do for
>>>> SCAN_PAGE_DIRTY_OR_WRITEBACK? There's already retry logic there, and this
>>>> would also simplify the long collapse_file().
>>>
>>> That would be cleaner, yeah. Some older stable trees don't have that
>>> outer retry loop, though ... I'd prefer to get the fix backported first,
>>> then move the RA/retry logic out in a follow-up, wdyt?
>>
>> IIRC, the approach to bug fixes is to fix bugs properly and cleanly for
>> upstream, without being constrained by backporting requirements.
>>
>> Anyway, I don't have a strong opinion on this. Let's also see what David prefers.
> 
> Let's get this fixed in a acceptable way in a reasonable timeframe; it's been
> broken for too long. ... and follow up with bigger cleanups later.
> 
> @Lance is this version good to review for that purpose or are you planning a resend?

Right, as for the bigger cleanup, that can come later. Will resend the 
current version as-is :)