[PATCH 3/3] drm/amdkfd: destroy_pdds release pdd->drm_file at end

[Philip Yang]

On 2025-05-15 10:29, Chen, Xiaogang wrote:
>
> Does this patch fix a bug or just make code look more reasonable? 
> kfd_process_destroy_pdds releases pdd related buffers, not related to 
> operations on vm. So vm tear down dose not affect this function.
>
This change doesn't fix anything currently, as fput(pdd->drm_file) to 
free vm is right between free vm mapping qpd->cwsr_mem, qpd->ib_mem and 
free kernel bo qpd->proc_doorbells, pdd->proc_ctx_bo, to make it clear 
for future change.

Regards,

Philip

> Regards
>
> Xiaogang
>
> On 5/14/2025 12:10 PM, Philip Yang wrote:
>> Release pdd->drm_file may free the vm if this is the last reference,
>> move it to the last step after memory is unmapped.
>>
>> Signed-off-by: Philip Yang<Philip.Yang at amd.com>
>> ---
>>   drivers/gpu/drm/amd/amdkfd/kfd_process.c | 10 +++++++---
>>   1 file changed, 7 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
>> index e868cc8da46f..b009c852180d 100644
>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
>> @@ -1063,9 +1063,6 @@ static void kfd_process_destroy_pdds(struct kfd_process *p)
>>   		kfd_process_device_destroy_cwsr_dgpu(pdd);
>>   		kfd_process_device_destroy_ib_mem(pdd);
>>   
>> -		if (pdd->drm_file)
>> -			fput(pdd->drm_file);
>> -
>>   		if (pdd->qpd.cwsr_kaddr && !pdd->qpd.cwsr_base)
>>   			free_pages((unsigned long)pdd->qpd.cwsr_kaddr,
>>   				get_order(KFD_CWSR_TBA_TMA_SIZE));
>> @@ -1088,6 +1085,13 @@ static void kfd_process_destroy_pdds(struct kfd_process *p)
>>   			pdd->runtime_inuse = false;
>>   		}
>>   
>> +		/*
>> +		 * This may release the vm if application already close the drm node,
>> +		 * do it as last step after memory unmapped.
>> +		 */
>> +		if (pdd->drm_file)
>> +			fput(pdd->drm_file);
>> +
>>   		kfree(pdd);
>>   		p->pdds[i] = NULL;
>>   	}