[PATCH] drm/kfd: fix ttm_bo_release warning

[Yu, Lang]

[AMD Official Use Only]



>-----Original Message-----
>From: Koenig, Christian <Christian.Koenig at amd.com>
>Sent: Thursday, September 23, 2021 7:40 PM
>To: Yu, Lang <Lang.Yu at amd.com>; amd-gfx at lists.freedesktop.org
>Cc: Kuehling, Felix <Felix.Kuehling at amd.com>; Christian K nig
><C3B6christian.koenig at amd.com>; Huang, Ray <Ray.Huang at amd.com>
>Subject: Re: [PATCH] drm/kfd: fix ttm_bo_release warning
>
>
>
>Am 23.09.21 um 11:44 schrieb Lang Yu:
>> If a BO is pinned, unpin it before freeing it.
>>
>> Call Trace:
>> 	ttm_bo_put+0x30/0x50 [ttm]
>> 	amdgpu_bo_unref+0x1e/0x30 [amdgpu]
>> 	amdgpu_gem_object_free+0x34/0x50 [amdgpu]
>> 	drm_gem_object_free+0x1d/0x30 [drm]
>> 	amdgpu_amdkfd_gpuvm_free_memory_of_gpu+0x31f/0x3a0 [amdgpu]
>> 	kfd_process_device_free_bos+0xa3/0xf0 [amdgpu]
>> 	kfd_process_wq_release+0x224/0x2e0 [amdgpu]
>> 	process_one_work+0x220/0x3c0
>> 	worker_thread+0x4d/0x3f0
>> 	kthread+0x114/0x150
>> 	process_one_work+0x3c0/0x3c0
>> 	kthread_park+0x90/0x90
>> 	ret_from_fork+0x22/0x30
>>
>> Signed-off-by: Lang Yu <lang.yu at amd.com>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 3 +++
>>   1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
>b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
>> index 2d6b2d77b738..7e693b064072 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
>> @@ -1567,6 +1567,9 @@ int amdgpu_amdkfd_gpuvm_free_memory_of_gpu(
>>   	pr_debug("Release VA 0x%llx - 0x%llx\n", mem->va,
>>   		mem->va + bo_size * (1 + mem->aql_queue));
>>
>> +	if (mem->bo->tbo.pin_count)
>> +		amdgpu_bo_unpin(mem->bo);
>> +
>
>NAK, using mem->bo->tbo.pin_count like this is illegal.

I didn't  get your point. I referred to function-"void amdgpu_bo_unpin(struct amdgpu_bo *bo)",
which uses it like this.

>Where was the BO pinned in the first place?

I found two places:

	ret = kfd_process_alloc_gpuvm(pdd, qpd->ib_base, PAGE_SIZE, flags,
				      &kaddr);

	ret = kfd_process_alloc_gpuvm(pdd, qpd->cwsr_base,
				      KFD_CWSR_TBA_TMA_SIZE, flags, &kaddr);
Regards,
Lang

>Christian.
>
>>   	ret = unreserve_bo_and_vms(&ctx, false, false);
>>
>>   	/* Remove from VM internal data structures */