[PATCH 1/3] drm/amdgpu: fix gtt mgr available statistics

[zhoucm1]

On 2017年04月19日 14:38, Christian König wrote:
> Am 19.04.2017 um 05:50 schrieb Chunming Zhou:
>> gtt_mgr_alloc is called by many places in local driver, while
>> gtt_mgr_new is called by get_node in ttm.
>
> NAK, that can lead to over allocating the address space and we can't 
> handle that during suspend/resume.
I didn't get your mean here.

Describe it first from my side, I found this issue on APU like carrizo, 
vram is little, so gtt is used much more, we always found the gtt cannot 
be used end up and results in Game failed to allocate memory, but from 
dumping mm hole table, there are many free hole and memory.
The root cause is mgr->available statistic is incorrect, which doesn't 
match dump mm table.
I think mgr->available should only be changed when insert/free node.

Regards,
David Zhou
>
> Regards,
> Christian.
>
>>
>> Change-Id: Ia5a18a3b531a01ad7d47f40e08f778e7b94c048a
>> Signed-off-by: Chunming Zhou <David1.Zhou at amd.com>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c | 11 +++++------
>>   1 file changed, 5 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c 
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c
>> index 69ab2ee..8a950a5 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c
>> @@ -124,6 +124,8 @@ int amdgpu_gtt_mgr_alloc(struct 
>> ttm_mem_type_manager *man,
>>       r = drm_mm_insert_node_in_range_generic(&mgr->mm, node, 
>> mem->num_pages,
>>                           mem->page_alignment, 0,
>>                           fpfn, lpfn, sflags, aflags);
>> +    if (!r)
>> +        mgr->available -= mem->num_pages;
>>       spin_unlock(&mgr->lock);
>>         if (!r) {
>> @@ -160,7 +162,6 @@ static int amdgpu_gtt_mgr_new(struct 
>> ttm_mem_type_manager *man,
>>           spin_unlock(&mgr->lock);
>>           return 0;
>>       }
>> -    mgr->available -= mem->num_pages;
>>       spin_unlock(&mgr->lock);
>>         node = kzalloc(sizeof(*node), GFP_KERNEL);
>> @@ -187,9 +188,6 @@ static int amdgpu_gtt_mgr_new(struct 
>> ttm_mem_type_manager *man,
>>         return 0;
>>   err_out:
>> -    spin_lock(&mgr->lock);
>> -    mgr->available += mem->num_pages;
>> -    spin_unlock(&mgr->lock);
>>         return r;
>>   }
>> @@ -214,9 +212,10 @@ static void amdgpu_gtt_mgr_del(struct 
>> ttm_mem_type_manager *man,
>>           return;
>>         spin_lock(&mgr->lock);
>> -    if (node->start != AMDGPU_BO_INVALID_OFFSET)
>> +    if (node->start != AMDGPU_BO_INVALID_OFFSET) {
>>           drm_mm_remove_node(node);
>> -    mgr->available += mem->num_pages;
>> +        mgr->available += mem->num_pages;
>> +    }
>>       spin_unlock(&mgr->lock);
>>         kfree(node);
>
>