Re: [PATCH v3 3/6] mm/huge_memory: respect MADV_COLLAPSE with PR_THP_DISABLE_EXCEPT_ADVISED

[Usama Arif <usamaarif642@gmail.com>]

>> diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h
>> index 9c1d6e49b8a9..cdda963a039a 100644
>> --- a/include/uapi/linux/prctl.h
>> +++ b/include/uapi/linux/prctl.h
>> @@ -185,7 +185,7 @@ struct prctl_mm_map {
>>  #define PR_SET_THP_DISABLE	41
>>  /*
>>   * Don't disable THPs when explicitly advised (e.g., MADV_HUGEPAGE /
>> - * VM_HUGEPAGE).
>> + * VM_HUGEPAGE, MADV_COLLAPSE).
>>   */
>>  # define PR_THP_DISABLE_EXCEPT_ADVISED	(1 << 1)
>>  #define PR_GET_THP_DISABLE	42
>> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
>> index 85252b468f80..ef5ccb0ec5d5 100644
>> --- a/mm/huge_memory.c
>> +++ b/mm/huge_memory.c
>> @@ -104,7 +104,8 @@ unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma,
>>  {
>>  	const bool smaps = type == TVA_SMAPS;
>>  	const bool in_pf = type == TVA_PAGEFAULT;
>> -	const bool enforce_sysfs = type != TVA_FORCED_COLLAPSE;
>> +	const bool forced_collapse = type == TVA_FORCED_COLLAPSE;
>> +	const bool enforce_sysfs = !forced_collapse;
> 
> I guess as discussed we'll return to this.
> 

Thanks for the review!

Yes I have a follow up patch ready, will send that when things stabalize and this series
makes into mm-new.