Re: [v1 resend 03/12] mm/thp: zone_device awareness in THP handling code

[Balbir Singh <balbirs@nvidia.com>]

On 7/4/25 21:10, Mika Penttilä wrote:
>>  /* Racy check whether the huge page can be split */
>> @@ -3543,6 +3594,10 @@ static int __split_unmapped_folio(struct folio *folio, int new_order,
>>  					((mapping || swap_cache) ?
>>  						folio_nr_pages(release) : 0));
>>  
>> +			if (folio_is_device_private(release))
>> +				percpu_ref_get_many(&release->pgmap->ref,
>> +							(1 << new_order) - 1);
> 
> pgmap refcount should not be modified here, count should remain the same after the split also
> 
> 

Good point, let me revisit the accounting

For this patch series, the tests did not catch it since new ref's evaluate to 0

Thanks,
Balbir Singh