Re: [PATCH 8/8] drm/amdgpu: add drm buddy support to amdgpu

[Matthew Auld <matthew.auld@intel.com>]

On 04/11/2021 07:34, Christian König wrote:
> 
> 
> Am 03.11.21 um 20:25 schrieb Matthew Auld:
>> On 25/10/2021 14:00, Arunpravin wrote:
>>> - Remove drm_mm references and replace with drm buddy functionalities
>>> - Add res cursor support for drm buddy
>>>
>>> Signed-off-by: Arunpravin <Arunpravin.PaneerSelvam@amd.com>
>>
>> <snip>
>>
>>> +        spin_lock(&mgr->lock);
>>> +        r = drm_buddy_alloc(mm, (uint64_t)place->fpfn << PAGE_SHIFT,
>>> +                    (uint64_t)lpfn << PAGE_SHIFT,
>>> +                    (uint64_t)n_pages << PAGE_SHIFT,
>>> +                     min_page_size, &node->blocks,
>>> +                     node->flags);
>>
>>
>> Is spinlock + GFP_KERNEL allowed?
> 
> Nope it isn't, but does that function really calls kmalloc()?

It calls kmem_cache_zalloc(..., GFP_KERNEL)

> 
> Christian.
> 
>>
>>> +        spin_unlock(&mgr->lock);
>>> +
>>> +        if (unlikely(r))
>>> +            goto error_free_blocks;
>>> +
>>>           pages_left -= pages;
>>>           ++i;
>>>             if (pages > pages_left)
>>>               pages = pages_left;
>>>       }
>>> -    spin_unlock(&mgr->lock);
>>> +
>>> +    /* Free unused pages for contiguous allocation */
>>> +    if (place->flags & TTM_PL_FLAG_CONTIGUOUS) {
>>> +        uint64_t actual_size = (uint64_t)node->base.num_pages << 
>>> PAGE_SHIFT;
>>> +
>>> +        r = drm_buddy_free_unused_pages(mm,
>>> +                        actual_size,
>>> +                        &node->blocks);
>>
>> Needs some locking.
>