Re: [PATCH v5 3/4] mm: thp: use folio_batch to handle THP splitting in deferred_split_scan()

[Qi Zheng <qi.zheng@linux.dev>]

On 11/7/25 10:29 AM, Andrew Morton wrote:
> On Thu, 6 Nov 2025 14:52:13 +0000 Wei Yang <richard.weiyang@gmail.com> wrote:
> 
>>> +		if (folio_order(folio) > 1) {
>>> +			if (!list_empty(&folio->_deferred_list)) {
>>> +				ds_queue->split_queue_len--;
>>> +				/*
>>> +				 * Reinitialize page_deferred_list after removing the
>>> +				 * page from the split_queue, otherwise a subsequent
>>> +				 * split will see list corruption when checking the
>>> +				 * page_deferred_list.
>>> +				 */
>>> +				list_del_init(&folio->_deferred_list);
>>> +			}
>>> 			if (folio_test_partially_mapped(folio)) {
>>> 				folio_clear_partially_mapped(folio);
>>> 				mod_mthp_stat(folio_order(folio),
>>> 					      MTHP_STAT_NR_ANON_PARTIALLY_MAPPED, -1);
>>> 			}
>>> -			/*
>>> -			 * Reinitialize page_deferred_list after removing the
>>> -			 * page from the split_queue, otherwise a subsequent
>>> -			 * split will see list corruption when checking the
>>> -			 * page_deferred_list.
>>> -			 */
>>> -			list_del_init(&folio->_deferred_list);
>>
>> @Andrew
>>
>> Current mm-new looks not merge the code correctly?
>>
> 
> It happens.  We presently have 29 patches which alter mm/huge_memory.c.
> 
> Thanks for checking.  I'll drop version 5 of "reparent the THP split queue".
> 
> Please check what remains, and send a v6 against tomorrow's
> mm-new/mm-unstable.

OK, will rebase and resend it.