[PATCH v3 4/6] drm/i915: Implement intersect/compatible functions
Arunpravin Paneer Selvam
arunpravin.paneerselvam at amd.com
Fri Jul 29 06:10:58 UTC 2022
On 7/28/2022 8:57 PM, Matthew Auld wrote:
> On 28/07/2022 15:33, Arunpravin Paneer Selvam wrote:
>> Implemented a new intersect and compatible callback function
>> fetching start offset from drm buddy allocator.
>>
>> v2: move the bits that are specific to buddy_man (Matthew)
>>
>> Signed-off-by: Christian König <christian.koenig at amd.com>
>> Signed-off-by: Arunpravin Paneer Selvam
>> <Arunpravin.PaneerSelvam at amd.com>
>> ---
>> drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 39 +-----------
>> drivers/gpu/drm/i915/i915_ttm_buddy_manager.c | 62 +++++++++++++++++++
>> 2 files changed, 64 insertions(+), 37 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
>> b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
>> index 70e2ed4e99df..54eead15d74b 100644
>> --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
>> @@ -396,43 +396,8 @@ static bool i915_ttm_eviction_valuable(struct
>> ttm_buffer_object *bo,
>> if (!i915_gem_object_evictable(obj))
>> return false;
>> - switch (res->mem_type) {
>> - case I915_PL_LMEM0: {
>> - struct ttm_resource_manager *man =
>> - ttm_manager_type(bo->bdev, res->mem_type);
>> - struct i915_ttm_buddy_resource *bman_res =
>> - to_ttm_buddy_resource(res);
>> - struct drm_buddy *mm = bman_res->mm;
>> - struct drm_buddy_block *block;
>> -
>> - if (!place->fpfn && !place->lpfn)
>> - return true;
>> -
>> - GEM_BUG_ON(!place->lpfn);
>> -
>> - /*
>> - * If we just want something mappable then we can quickly check
>> - * if the current victim resource is using any of the CPU
>> - * visible portion.
>> - */
>> - if (!place->fpfn &&
>> - place->lpfn == i915_ttm_buddy_man_visible_size(man))
>> - return bman_res->used_visible_size > 0;
>> -
>> - /* Real range allocation */
>> - list_for_each_entry(block, &bman_res->blocks, link) {
>> - unsigned long fpfn =
>> - drm_buddy_block_offset(block) >> PAGE_SHIFT;
>> - unsigned long lpfn = fpfn +
>> - (drm_buddy_block_size(mm, block) >> PAGE_SHIFT);
>> -
>> - if (place->fpfn < lpfn && place->lpfn > fpfn)
>> - return true;
>> - }
>> - return false;
>> - } default:
>> - break;
>> - }
>> + if (res->mem_type == I915_PL_LMEM0)
>> + return ttm_bo_eviction_valuable(bo, place);
>
> We should be able to drop the mem_type == I915_PL_LMEM0 check here I
> think, and just unconditionally do:
>
> return ttm_bo_eviction_valuable(bo, place);
okay
>
>> return true;
>> }
>> diff --git a/drivers/gpu/drm/i915/i915_ttm_buddy_manager.c
>> b/drivers/gpu/drm/i915/i915_ttm_buddy_manager.c
>> index a5109548abc0..9d2a31154d58 100644
>> --- a/drivers/gpu/drm/i915/i915_ttm_buddy_manager.c
>> +++ b/drivers/gpu/drm/i915/i915_ttm_buddy_manager.c
>> @@ -178,6 +178,66 @@ static void i915_ttm_buddy_man_free(struct
>> ttm_resource_manager *man,
>> kfree(bman_res);
>> }
>> +static bool i915_ttm_buddy_man_intersect(struct
>> ttm_resource_manager *man,
>
> Nit: intersects
ok
>
>> + struct ttm_resource *res,
>> + const struct ttm_place *place,
>> + size_t size)
>> +{
>> + struct i915_ttm_buddy_resource *bman_res =
>> to_ttm_buddy_resource(res);
>> + u32 start, num_pages = PFN_UP(size);
>> + struct drm_buddy_block *block;
>> +
>> + if (!place->fpfn && !place->lpfn)
>> + return true;
I place bug_on check here
GEM_BUG_ON(!place->lpfn);
>> +
>> + /*
>> + * If we just want something mappable then we can quickly check
>> + * if the current victim resource is using any of the CP
>> + * visible portion.
>> + */
>> + if (!place->fpfn &&
>> + place->lpfn == i915_ttm_buddy_man_visible_size(man))
>> + return bman_res->used_visible_size > 0;
>> +
>> + /* Check each drm buddy block individually */
>> + list_for_each_entry(block, &bman_res->blocks, link) {
>> + start = drm_buddy_block_offset(block) >> PAGE_SHIFT;
>> + /* Don't evict BOs outside of the requested placement range */
>> + if (place->fpfn >= (start + num_pages) ||
>> + (place->lpfn && place->lpfn <= start))
>> + return false;
>> + }
>> +
>> + return true;
>
> We need to account for the block size somewhere. Also same bug in the
> amdgpu patch it seems. We also need to do this the other way around
> and keep checking until we find something that overlaps, for example
> if the first block doesn't intersect/overlap we will incorrectly
> return false here, even if one of the other blocks does intersect.
>
> list_for_each_entry() {
> fpfn = drm_buddy_block_size(mm, block) >> PAGE_SHIFT;
> lpfn = fpfn + drm_buddy_block_size(mm, block) >> PAGE_SHIFT);
>
> if (place->fpfn < lpfn && place->lpfn > fpfn)
> return true;
> }
>
> return false;
yes, here the final code looks like,
list_for_each_entry(block, &bman_res->blocks, link) {
unsigned long fpfn =
drm_buddy_block_offset(block) >> PAGE_SHIFT;
unsigned long lpfn = fpfn +
(drm_buddy_block_size(mm, block) >> PAGE_SHIFT);
/* Don't evict BOs outside of the requested placement
range */
if (place->fpfn < lpfn && place->lpfn > fpfn)
return true;
}
return false;
>
>> +}
>> +
>> +static bool i915_ttm_buddy_man_compatible(struct
>> ttm_resource_manager *man,
>> + struct ttm_resource *res,
>> + const struct ttm_place *place,
>> + size_t size)
>> +{
>> + struct i915_ttm_buddy_resource *bman_res =
>> to_ttm_buddy_resource(res);
>> + u32 start, num_pages = PFN_UP(size);
>> + struct drm_buddy_block *block;
>> +
>> + if (!place->fpfn && !place->lpfn)
>> + return true;
I place bug_on check here
GEM_BUG_ON(!place->lpfn);
>> +
>> + if (!place->fpfn &&
>> + place->lpfn == i915_ttm_buddy_man_visible_size(man))
>> + return bman_res->used_visible_size == res->num_pages;
>> +
>> + /* Check each drm buddy block individually */
>> + list_for_each_entry(block, &bman_res->blocks, link) {
>> + start = drm_buddy_block_offset(block) >> PAGE_SHIFT;
>> + if (start < place->fpfn ||
>> + (place->lpfn && (start + num_pages) > place->lpfn))
>
> Same here. We need to consider the block size/range.
ahh somehow missed the block size, here the final code looks like,
/* Check each drm buddy block individually */
list_for_each_entry(block, &bman_res->blocks, link) {
unsigned long fpfn =
drm_buddy_block_offset(block) >> PAGE_SHIFT;
unsigned long lpfn = fpfn +
(drm_buddy_block_size(mm, block) >> PAGE_SHIFT);
if (fpfn < place->fpfn || lpfn > place->lpfn)
return false;
}
return true;
>
> Otherwise I think looks good.
>
>> + return false;
>> + }
>> +
>> + return true;
>> +}
>> +
>> static void i915_ttm_buddy_man_debug(struct ttm_resource_manager *man,
>> struct drm_printer *printer)
>> {
>> @@ -205,6 +265,8 @@ static void i915_ttm_buddy_man_debug(struct
>> ttm_resource_manager *man,
>> static const struct ttm_resource_manager_func
>> i915_ttm_buddy_manager_func = {
>> .alloc = i915_ttm_buddy_man_alloc,
>> .free = i915_ttm_buddy_man_free,
>> + .intersects = i915_ttm_buddy_man_intersect,
>> + .compatible = i915_ttm_buddy_man_compatible,
>> .debug = i915_ttm_buddy_man_debug,
>> };
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