-----Original Message----- From: amd-gfx amd-gfx-bounces@lists.freedesktop.org On Behalf Of Christian König Sent: Wednesday, March 23, 2022 1:07 PM To: Paneer Selvam, Arunpravin Arunpravin.PaneerSelvam@amd.com; intel-gfx@lists.freedesktop.org; dri-devel@lists.freedesktop.org; amd-gfx@lists.freedesktop.org Cc: Deucher, Alexander Alexander.Deucher@amd.com; matthew.auld@intel.com; daniel@ffwll.ch; Koenig, Christian Christian.Koenig@amd.com Subject: Re: [PATCH v11] drm/amdgpu: add drm buddy support to amdgpu
Am 23.03.22 um 07:25 schrieb Arunpravin Paneer Selvam:
[SNIP] @@ -415,48 +409,86 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man, goto error_fini; }
- mode = DRM_MM_INSERT_BEST;
- INIT_LIST_HEAD(&node->blocks);
- if (place->flags & TTM_PL_FLAG_TOPDOWN)
mode = DRM_MM_INSERT_HIGH;
node->flags |= DRM_BUDDY_TOPDOWN_ALLOCATION;
- pages_left = node->base.num_pages;
- if (place->fpfn || lpfn != man->size >> PAGE_SHIFT)
/* Allocate blocks in desired range */node->flags |= DRM_BUDDY_RANGE_ALLOCATION;
- /* Limit maximum size to 2GB due to SG table limitations */
- pages = min(pages_left, 2UL << (30 - PAGE_SHIFT));
- BUG_ON(!node->base.num_pages);
Please drop this BUG_ON(). This is not something which prevents further data corruption, so the BUG_ON() is not justified.
ok
pages_left = node->base.num_pages;
i = 0;
- spin_lock(&mgr->lock); while (pages_left) {
uint32_t alignment = tbo->page_alignment;
if (tbo->page_alignment)min_page_size = tbo->page_alignment << PAGE_SHIFT;elsemin_page_size = mgr->default_page_size;The handling here looks extremely awkward to me.
min_page_size should be determined outside of the loop, based on default_page_size, alignment and contiguous flag.
I kept min_page_size determine logic inside the loop for cases 2GiB+ requirements, Since now we are round up the size to the required alignment, I modified the min_page_size determine logic outside of the loop in v12. Please review.
Then why do you drop the lock and grab it again inside the loop? And what is "i" actually good for?
modified the lock/unlock placement in v12.
"i" is to track when there is 2GiB+ contiguous allocation request, first we allocate 2GiB (due to SG table limit) continuously and the remaining pages in the next iteration, hence this request can't be a continuous. To set the placement flag we make use of "i" value. In our case "i" value becomes 2 and we don't set the below flag. node->base.placement |= TTM_PL_FLAG_CONTIGUOUS;
If we don't get such requests, I will remove "i".
/* Limit maximum size to 2GB due to SG table limitations */pages = min(pages_left, 2UL << (30 - PAGE_SHIFT));if (pages >= pages_per_node)
alignment = pages_per_node;r = drm_mm_insert_node_in_range(mm, &node->mm_nodes[i], pages,alignment, 0, place->fpfn,lpfn, mode);if (unlikely(r)) {if (pages > pages_per_node) {if (is_power_of_2(pages))pages = pages / 2;elsepages = rounddown_pow_of_two(pages);continue;}goto error_free;
min_page_size = pages_per_node << PAGE_SHIFT;if (!is_contiguous && !IS_ALIGNED(pages, min_page_size >> PAGE_SHIFT))is_contiguous = 1;if (is_contiguous) {pages = roundup_pow_of_two(pages);min_page_size = pages << PAGE_SHIFT;if (pages > lpfn)lpfn = pages;
vis_usage += amdgpu_vram_mgr_vis_size(adev, &node->mm_nodes[i]);amdgpu_vram_mgr_virt_start(&node->base, &node->mm_nodes[i]);pages_left -= pages;
BUG_ON(min_page_size < mm->chunk_size);mutex_lock(&mgr->lock);r = drm_buddy_alloc_blocks(mm, (u64)place->fpfn << PAGE_SHIFT,(u64)lpfn << PAGE_SHIFT,(u64)pages << PAGE_SHIFT,min_page_size,&node->blocks,node->flags);mutex_unlock(&mgr->lock);if (unlikely(r))goto error_free_blocks;++i;
if (pages > pages_left)
pages = pages_left;
pages_left = 0;elsepages_left -= pages;
spin_unlock(&mgr->lock);
if (i == 1)
- /* Free unused pages for contiguous allocation */
- if (is_contiguous) {
Well that looks really odd, why is trimming not part of drm_buddy_alloc_blocks() ?
we didn't place trim function part of drm_buddy_alloc_blocks since we thought this function can be a generic one and it can be used by any other application as well. For example, now we are using it for trimming the last block in case of size non-alignment with min_page_size.
u64 actual_size = (u64)node->base.num_pages << PAGE_SHIFT;mutex_lock(&mgr->lock);drm_buddy_block_trim(mm,actual_size,&node->blocks);Why is the drm_buddy_block_trim() function given all the blocks and not just the last one?
modified in v12.
Regards, Christian.
mutex_unlock(&mgr->lock);}
list_for_each_entry(block, &node->blocks, link)
vis_usage += amdgpu_vram_mgr_vis_size(adev, block);block = amdgpu_vram_mgr_first_block(&node->blocks);
if (!block) {
r = -EINVAL;goto error_fini;}
node->base.start = amdgpu_node_start(block) >> PAGE_SHIFT;
if (i == 1 && is_contiguous) node->base.placement |= TTM_PL_FLAG_CONTIGUOUS;
if (adev->gmc.xgmi.connected_to_cpu) @@ -468,13 +500,13 @@ static
int amdgpu_vram_mgr_new(struct ttm_resource_manager *man, *res = &node->base; return 0;
-error_free:
- while (i--)
drm_mm_remove_node(&node->mm_nodes[i]);- spin_unlock(&mgr->lock);
+error_free_blocks:
- mutex_lock(&mgr->lock);
- drm_buddy_free_list(mm, &node->blocks);
- mutex_unlock(&mgr->lock); error_fini: ttm_resource_fini(man, &node->base);
- kvfree(node);
kfree(node);
return r; }
@@ -490,27 +522,26 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man, static void amdgpu_vram_mgr_del(struct ttm_resource_manager *man, struct ttm_resource *res) {
- struct ttm_range_mgr_node *node = to_ttm_range_mgr_node(res);
- struct amdgpu_vram_mgr_node *node = to_amdgpu_vram_mgr_node(res); struct amdgpu_vram_mgr *mgr = to_vram_mgr(man); struct amdgpu_device *adev = to_amdgpu_device(mgr);
- struct drm_buddy *mm = &mgr->mm;
- struct drm_buddy_block *block; uint64_t vis_usage = 0;
unsigned i, pages;
spin_lock(&mgr->lock);
for (i = 0, pages = res->num_pages; pages;
pages -= node->mm_nodes[i].size, ++i) {struct drm_mm_node *mm = &node->mm_nodes[i];
- mutex_lock(&mgr->lock);
- list_for_each_entry(block, &node->blocks, link)
vis_usage += amdgpu_vram_mgr_vis_size(adev, block);
drm_mm_remove_node(mm);vis_usage += amdgpu_vram_mgr_vis_size(adev, mm);- } amdgpu_vram_mgr_do_reserve(man);
- spin_unlock(&mgr->lock);
drm_buddy_free_list(mm, &node->blocks);
mutex_unlock(&mgr->lock);
atomic64_sub(vis_usage, &mgr->vis_usage);
ttm_resource_fini(man, res);
- kvfree(node);
kfree(node); }
/**
@@ -648,13 +679,22 @@ static void amdgpu_vram_mgr_debug(struct ttm_resource_manager *man, struct drm_printer *printer) { struct amdgpu_vram_mgr *mgr = to_vram_mgr(man);
struct drm_buddy *mm = &mgr->mm;
struct drm_buddy_block *block;
drm_printf(printer, " vis usage:%llu\n", amdgpu_vram_mgr_vis_usage(mgr));
- spin_lock(&mgr->lock);
- drm_mm_print(&mgr->mm, printer);
- spin_unlock(&mgr->lock);
mutex_lock(&mgr->lock);
drm_printf(printer, "default_page_size: %lluKiB\n",
mgr->default_page_size >> 10);drm_buddy_print(mm, printer);
drm_printf(printer, "reserved:\n");
list_for_each_entry(block, &mgr->reserved_pages, link)
drm_buddy_block_print(mm, block, printer);mutex_unlock(&mgr->lock); }
static const struct ttm_resource_manager_func amdgpu_vram_mgr_func =
{ @@ -674,16 +714,21 @@ int amdgpu_vram_mgr_init(struct amdgpu_device *adev) { struct amdgpu_vram_mgr *mgr = &adev->mman.vram_mgr; struct ttm_resource_manager *man = &mgr->manager;
int err;
ttm_resource_manager_init(man, &adev->mman.bdev, adev->gmc.real_vram_size);
man->func = &amdgpu_vram_mgr_func;
- drm_mm_init(&mgr->mm, 0, man->size >> PAGE_SHIFT);
- spin_lock_init(&mgr->lock);
err = drm_buddy_init(&mgr->mm, man->size, PAGE_SIZE);
if (err)
return err;mutex_init(&mgr->lock); INIT_LIST_HEAD(&mgr->reservations_pending); INIT_LIST_HEAD(&mgr->reserved_pages);
mgr->default_page_size = PAGE_SIZE;
ttm_set_driver_manager(&adev->mman.bdev, TTM_PL_VRAM, &mgr->manager); ttm_resource_manager_set_used(man, true); @@ -711,16 +756,16 @@
void amdgpu_vram_mgr_fini(struct amdgpu_device *adev) if (ret) return;
- spin_lock(&mgr->lock);
mutex_lock(&mgr->lock); list_for_each_entry_safe(rsv, temp, &mgr->reservations_pending, node) kfree(rsv);
list_for_each_entry_safe(rsv, temp, &mgr->reserved_pages, node) {
drm_mm_remove_node(&rsv->mm_node);
drm_buddy_free_list(&mgr->mm, &rsv->block);
- drm_mm_takedown(&mgr->mm);
- spin_unlock(&mgr->lock);
drm_buddy_fini(&mgr->mm);
mutex_unlock(&mgr->lock);
ttm_resource_manager_cleanup(man); ttm_set_driver_manager(&adev->mman.bdev, TTM_PL_VRAM, NULL);
base-commit: a678f97326454b60ffbbde6abf52d23997d71a27
Am 29.03.22 um 13:19 schrieb Arunpravin Paneer Selvam:
[SNIP]
pages_left = node->base.num_pages;
i = 0;
- spin_lock(&mgr->lock); while (pages_left) {
uint32_t alignment = tbo->page_alignment;
if (tbo->page_alignment)min_page_size = tbo->page_alignment << PAGE_SHIFT;elsemin_page_size = mgr->default_page_size;The handling here looks extremely awkward to me.
min_page_size should be determined outside of the loop, based on default_page_size, alignment and contiguous flag.
I kept min_page_size determine logic inside the loop for cases 2GiB+ requirements, Since now we are round up the size to the required alignment, I modified the min_page_size determine logic outside of the loop in v12. Please review.
Ah! So do we only have the loop so that each allocation isn't bigger than 2GiB? If yes couldn't we instead add a max_alloc_size or something similar?
BTW: I strongly suggest that you rename min_page_size to min_alloc_size. Otherwise somebody could think that those numbers are in pages and not bytes.
Then why do you drop the lock and grab it again inside the loop? And what is "i" actually good for?
modified the lock/unlock placement in v12.
"i" is to track when there is 2GiB+ contiguous allocation request, first we allocate 2GiB (due to SG table limit) continuously and the remaining pages in the next iteration, hence this request can't be a continuous. To set the placement flag we make use of "i" value. In our case "i" value becomes 2 and we don't set the below flag. node->base.placement |= TTM_PL_FLAG_CONTIGUOUS;
If we don't get such requests, I will remove "i".
I'm not sure if that works.
As far as I can see drm_buddy_alloc_blocks() can allocate multiple blocks at the same time, but i is only incremented when we loop.
So what you should do instead is to check if node->blocks just contain exactly one element after the allocation but before the trim.
/* Limit maximum size to 2GB due to SG table limitations */pages = min(pages_left, 2UL << (30 - PAGE_SHIFT)); if (pages >= pages_per_node)
alignment = pages_per_node;r = drm_mm_insert_node_in_range(mm, &node->mm_nodes[i], pages,alignment, 0, place->fpfn,lpfn, mode);if (unlikely(r)) {if (pages > pages_per_node) {if (is_power_of_2(pages))pages = pages / 2;elsepages = rounddown_pow_of_two(pages);continue;}goto error_free;
min_page_size = pages_per_node << PAGE_SHIFT;if (!is_contiguous && !IS_ALIGNED(pages, min_page_size >> PAGE_SHIFT))is_contiguous = 1;if (is_contiguous) {pages = roundup_pow_of_two(pages);min_page_size = pages << PAGE_SHIFT;if (pages > lpfn)lpfn = pages; }
vis_usage += amdgpu_vram_mgr_vis_size(adev, &node->mm_nodes[i]);amdgpu_vram_mgr_virt_start(&node->base, &node->mm_nodes[i]);pages_left -= pages;
BUG_ON(min_page_size < mm->chunk_size);mutex_lock(&mgr->lock);r = drm_buddy_alloc_blocks(mm, (u64)place->fpfn << PAGE_SHIFT,(u64)lpfn << PAGE_SHIFT,(u64)pages << PAGE_SHIFT,min_page_size,&node->blocks,node->flags);mutex_unlock(&mgr->lock);if (unlikely(r))goto error_free_blocks;++i; if (pages > pages_left)
pages = pages_left;
pages_left = 0;elsepages_left -= pages;
spin_unlock(&mgr->lock);
if (i == 1)
- /* Free unused pages for contiguous allocation */
- if (is_contiguous) {
Well that looks really odd, why is trimming not part of drm_buddy_alloc_blocks() ?
we didn't place trim function part of drm_buddy_alloc_blocks since we thought this function can be a generic one and it can be used by any other application as well. For example, now we are using it for trimming the last block in case of size non-alignment with min_page_size.
Good argument. Another thing I just realized is that we probably want to double check if we only allocated one block before the trim.
Thanks, Christian.
On 29/03/22 4:54 pm, Christian König wrote:
Am 29.03.22 um 13:19 schrieb Arunpravin Paneer Selvam:
[SNIP]
pages_left = node->base.num_pages;
i = 0;
- spin_lock(&mgr->lock); while (pages_left) {
uint32_t alignment = tbo->page_alignment;
if (tbo->page_alignment)min_page_size = tbo->page_alignment << PAGE_SHIFT;elsemin_page_size = mgr->default_page_size;The handling here looks extremely awkward to me.
min_page_size should be determined outside of the loop, based on default_page_size, alignment and contiguous flag.
I kept min_page_size determine logic inside the loop for cases 2GiB+ requirements, Since now we are round up the size to the required alignment, I modified the min_page_size determine logic outside of the loop in v12. Please review.
Ah! So do we only have the loop so that each allocation isn't bigger than 2GiB? If yes couldn't we instead add a max_alloc_size or something similar?
yes we have the loop to limit the allocation not bigger than 2GiB, I think we cannot avoid the loop since we need to allocate the remaining pages if any, to complete the 2GiB+ size request. In other words, first iteration we limit the max size to 2GiB and in the second iteration we allocate the left over pages if any.
BTW: I strongly suggest that you rename min_page_size to min_alloc_size. Otherwise somebody could think that those numbers are in pages and not bytes.
modified in v12
Then why do you drop the lock and grab it again inside the loop? And what is "i" actually good for?
modified the lock/unlock placement in v12.
"i" is to track when there is 2GiB+ contiguous allocation request, first we allocate 2GiB (due to SG table limit) continuously and the remaining pages in the next iteration, hence this request can't be a continuous. To set the placement flag we make use of "i" value. In our case "i" value becomes 2 and we don't set the below flag. node->base.placement |= TTM_PL_FLAG_CONTIGUOUS;
If we don't get such requests, I will remove "i".
I'm not sure if that works.
As far as I can see drm_buddy_alloc_blocks() can allocate multiple blocks at the same time, but i is only incremented when we loop.
So what you should do instead is to check if node->blocks just contain exactly one element after the allocation but before the trim.
ok
/* Limit maximum size to 2GB due to SG table limitations */pages = min(pages_left, 2UL << (30 - PAGE_SHIFT)); if (pages >= pages_per_node)
alignment = pages_per_node;r = drm_mm_insert_node_in_range(mm, &node->mm_nodes[i], pages,alignment, 0, place->fpfn,lpfn, mode);if (unlikely(r)) {if (pages > pages_per_node) {if (is_power_of_2(pages))pages = pages / 2;elsepages = rounddown_pow_of_two(pages);continue;}goto error_free;
min_page_size = pages_per_node << PAGE_SHIFT;if (!is_contiguous && !IS_ALIGNED(pages, min_page_size >> PAGE_SHIFT))is_contiguous = 1;if (is_contiguous) {pages = roundup_pow_of_two(pages);min_page_size = pages << PAGE_SHIFT;if (pages > lpfn)lpfn = pages; }
vis_usage += amdgpu_vram_mgr_vis_size(adev, &node->mm_nodes[i]);amdgpu_vram_mgr_virt_start(&node->base, &node->mm_nodes[i]);pages_left -= pages;
BUG_ON(min_page_size < mm->chunk_size);mutex_lock(&mgr->lock);r = drm_buddy_alloc_blocks(mm, (u64)place->fpfn << PAGE_SHIFT,(u64)lpfn << PAGE_SHIFT,(u64)pages << PAGE_SHIFT,min_page_size,&node->blocks,node->flags);mutex_unlock(&mgr->lock);if (unlikely(r))goto error_free_blocks;++i; if (pages > pages_left)
pages = pages_left;
pages_left = 0;elsepages_left -= pages;
spin_unlock(&mgr->lock);
if (i == 1)
- /* Free unused pages for contiguous allocation */
- if (is_contiguous) {
Well that looks really odd, why is trimming not part of drm_buddy_alloc_blocks() ?
we didn't place trim function part of drm_buddy_alloc_blocks since we thought this function can be a generic one and it can be used by any other application as well. For example, now we are using it for trimming the last block in case of size non-alignment with min_page_size.
Good argument. Another thing I just realized is that we probably want to double check if we only allocated one block before the trim.
ok
Thanks, Christian.
On 29/03/22 9:30 pm, Arunpravin Paneer Selvam wrote:
On 29/03/22 4:54 pm, Christian König wrote:
Am 29.03.22 um 13:19 schrieb Arunpravin Paneer Selvam:
[SNIP]
pages_left = node->base.num_pages;
i = 0;
- spin_lock(&mgr->lock); while (pages_left) {
uint32_t alignment = tbo->page_alignment;
if (tbo->page_alignment)min_page_size = tbo->page_alignment << PAGE_SHIFT;elsemin_page_size = mgr->default_page_size;The handling here looks extremely awkward to me.
min_page_size should be determined outside of the loop, based on default_page_size, alignment and contiguous flag.
I kept min_page_size determine logic inside the loop for cases 2GiB+ requirements, Since now we are round up the size to the required alignment, I modified the min_page_size determine logic outside of the loop in v12. Please review.
Ah! So do we only have the loop so that each allocation isn't bigger than 2GiB? If yes couldn't we instead add a max_alloc_size or something similar?
yes we have the loop to limit the allocation not bigger than 2GiB, I think we cannot avoid the loop since we need to allocate the remaining pages if any, to complete the 2GiB+ size request. In other words, first iteration we limit the max size to 2GiB and in the second iteration we allocate the left over pages if any.
Hi Christian,
Here my understanding might be incorrect, should we limit the max size = 2GiB and skip all the remaining pages for a 2GiB+ request?
Thanks, Arun
BTW: I strongly suggest that you rename min_page_size to min_alloc_size. Otherwise somebody could think that those numbers are in pages and not bytes.
modified in v12
Then why do you drop the lock and grab it again inside the loop? And what is "i" actually good for?
modified the lock/unlock placement in v12.
"i" is to track when there is 2GiB+ contiguous allocation request, first we allocate 2GiB (due to SG table limit) continuously and the remaining pages in the next iteration, hence this request can't be a continuous. To set the placement flag we make use of "i" value. In our case "i" value becomes 2 and we don't set the below flag. node->base.placement |= TTM_PL_FLAG_CONTIGUOUS;
If we don't get such requests, I will remove "i".
I'm not sure if that works.
As far as I can see drm_buddy_alloc_blocks() can allocate multiple blocks at the same time, but i is only incremented when we loop.
So what you should do instead is to check if node->blocks just contain exactly one element after the allocation but before the trim.
ok
/* Limit maximum size to 2GB due to SG table limitations */pages = min(pages_left, 2UL << (30 - PAGE_SHIFT)); if (pages >= pages_per_node)
alignment = pages_per_node;r = drm_mm_insert_node_in_range(mm, &node->mm_nodes[i], pages,alignment, 0, place->fpfn,lpfn, mode);if (unlikely(r)) {if (pages > pages_per_node) {if (is_power_of_2(pages))pages = pages / 2;elsepages = rounddown_pow_of_two(pages);continue;}goto error_free;
min_page_size = pages_per_node << PAGE_SHIFT;if (!is_contiguous && !IS_ALIGNED(pages, min_page_size >> PAGE_SHIFT))is_contiguous = 1;if (is_contiguous) {pages = roundup_pow_of_two(pages);min_page_size = pages << PAGE_SHIFT;if (pages > lpfn)lpfn = pages; }
vis_usage += amdgpu_vram_mgr_vis_size(adev, &node->mm_nodes[i]);amdgpu_vram_mgr_virt_start(&node->base, &node->mm_nodes[i]);pages_left -= pages;
BUG_ON(min_page_size < mm->chunk_size);mutex_lock(&mgr->lock);r = drm_buddy_alloc_blocks(mm, (u64)place->fpfn << PAGE_SHIFT,(u64)lpfn << PAGE_SHIFT,(u64)pages << PAGE_SHIFT,min_page_size,&node->blocks,node->flags);mutex_unlock(&mgr->lock);if (unlikely(r))goto error_free_blocks;++i; if (pages > pages_left)
pages = pages_left;
pages_left = 0;elsepages_left -= pages;
spin_unlock(&mgr->lock);
if (i == 1)
- /* Free unused pages for contiguous allocation */
- if (is_contiguous) {
Well that looks really odd, why is trimming not part of drm_buddy_alloc_blocks() ?
we didn't place trim function part of drm_buddy_alloc_blocks since we thought this function can be a generic one and it can be used by any other application as well. For example, now we are using it for trimming the last block in case of size non-alignment with min_page_size.
Good argument. Another thing I just realized is that we probably want to double check if we only allocated one block before the trim.
ok
Thanks, Christian.
Am 29.03.22 um 21:18 schrieb Arunpravin Paneer Selvam:
On 29/03/22 9:30 pm, Arunpravin Paneer Selvam wrote:
On 29/03/22 4:54 pm, Christian König wrote:
Am 29.03.22 um 13:19 schrieb Arunpravin Paneer Selvam:
[SNIP]
pages_left = node->base.num_pages;
i = 0;
- spin_lock(&mgr->lock); while (pages_left) {
uint32_t alignment = tbo->page_alignment;
if (tbo->page_alignment)min_page_size = tbo->page_alignment << PAGE_SHIFT;elsemin_page_size = mgr->default_page_size;The handling here looks extremely awkward to me.
min_page_size should be determined outside of the loop, based on default_page_size, alignment and contiguous flag.
I kept min_page_size determine logic inside the loop for cases 2GiB+ requirements, Since now we are round up the size to the required alignment, I modified the min_page_size determine logic outside of the loop in v12. Please review.
Ah! So do we only have the loop so that each allocation isn't bigger than 2GiB? If yes couldn't we instead add a max_alloc_size or something similar?
yes we have the loop to limit the allocation not bigger than 2GiB, I think we cannot avoid the loop since we need to allocate the remaining pages if any, to complete the 2GiB+ size request. In other words, first iteration we limit the max size to 2GiB and in the second iteration we allocate the left over pages if any.
Hi Christian,
Here my understanding might be incorrect, should we limit the max size = 2GiB and skip all the remaining pages for a 2GiB+ request?
No, the total size can be bigger than 2GiB. Only the contained pages should be a maximum of 2GiB.
See drm_buddy_alloc_blocks() already has the loop you need inside of it, all you need to do is to restrict the maximum allocation order.
In other words you got this line here in drm_buddy_alloc_blocks:
order = fls(pages) - 1;
Which then would become:
oder = min(fls(pages), mm->max_order) - 1;
You then just need to give mm->max_order as parameter to drm_buddy_init() instead of trying to figure it out yourself. This would then also make the following BUG_ON() superfluous.
And btw: IIRC fls() uses only 32 bit! You should either use fls64() or directly ilog2() which optimizes and calls fls() or fls64() or constant log2 based on the data type.
Regards, Christian.
Thanks, Arun
BTW: I strongly suggest that you rename min_page_size to min_alloc_size. Otherwise somebody could think that those numbers are in pages and not bytes.
modified in v12
Then why do you drop the lock and grab it again inside the loop? And what is "i" actually good for?
modified the lock/unlock placement in v12.
"i" is to track when there is 2GiB+ contiguous allocation request, first we allocate 2GiB (due to SG table limit) continuously and the remaining pages in the next iteration, hence this request can't be a continuous. To set the placement flag we make use of "i" value. In our case "i" value becomes 2 and we don't set the below flag. node->base.placement |= TTM_PL_FLAG_CONTIGUOUS;
If we don't get such requests, I will remove "i".
I'm not sure if that works.
As far as I can see drm_buddy_alloc_blocks() can allocate multiple blocks at the same time, but i is only incremented when we loop.
So what you should do instead is to check if node->blocks just contain exactly one element after the allocation but before the trim.
ok
/* Limit maximum size to 2GB due to SG table limitations */pages = min(pages_left, 2UL << (30 - PAGE_SHIFT)); if (pages >= pages_per_node)
alignment = pages_per_node;r = drm_mm_insert_node_in_range(mm, &node->mm_nodes[i], pages,alignment, 0, place->fpfn,lpfn, mode);if (unlikely(r)) {if (pages > pages_per_node) {if (is_power_of_2(pages))pages = pages / 2;elsepages = rounddown_pow_of_two(pages);continue;}goto error_free;
min_page_size = pages_per_node << PAGE_SHIFT;if (!is_contiguous && !IS_ALIGNED(pages, min_page_size >> PAGE_SHIFT))is_contiguous = 1;if (is_contiguous) {pages = roundup_pow_of_two(pages);min_page_size = pages << PAGE_SHIFT;if (pages > lpfn)lpfn = pages; }
vis_usage += amdgpu_vram_mgr_vis_size(adev, &node->mm_nodes[i]);amdgpu_vram_mgr_virt_start(&node->base, &node->mm_nodes[i]);pages_left -= pages;
BUG_ON(min_page_size < mm->chunk_size);mutex_lock(&mgr->lock);r = drm_buddy_alloc_blocks(mm, (u64)place->fpfn << PAGE_SHIFT,(u64)lpfn << PAGE_SHIFT,(u64)pages << PAGE_SHIFT,min_page_size,&node->blocks,node->flags);mutex_unlock(&mgr->lock);if (unlikely(r))goto error_free_blocks;++i; if (pages > pages_left)
pages = pages_left;
pages_left = 0;elsepages_left -= pages; }
spin_unlock(&mgr->lock);
if (i == 1)
- /* Free unused pages for contiguous allocation */
- if (is_contiguous) {
Well that looks really odd, why is trimming not part of drm_buddy_alloc_blocks() ?
we didn't place trim function part of drm_buddy_alloc_blocks since we thought this function can be a generic one and it can be used by any other application as well. For example, now we are using it for trimming the last block in case of size non-alignment with min_page_size.
Good argument. Another thing I just realized is that we probably want to double check if we only allocated one block before the trim.
ok
Thanks, Christian.
dri-devel@lists.freedesktop.org
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Arunpravin Paneer Selvam -
Christian König