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

[Qi Zheng]

On 11/7/25 10:29 AM, Andrew Morton wrote:
> On Thu, 6 Nov 2025 14:52:13 +0000 Wei Yang <richard.weiyang@xxxxxxxxx> 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.