[PATCH 6/9] drm/amdgpu: remove VRAM accounting

Christian König ckoenig.leichtzumerken at gmail.com
Wed Feb 9 12:09:04 UTC 2022



Am 09.02.22 um 10:53 schrieb Matthew Auld:
> On Wed, 9 Feb 2022 at 08:41, Christian König
> <ckoenig.leichtzumerken at gmail.com> wrote:
>> This is provided by TTM now.
>>
>> Also switch man->size to bytes instead of pages and fix the double
>> printing of size and usage in debugfs.
>>
>> Signed-off-by: Christian König <christian.koenig at amd.com>
>> Tested-by: Bas Nieuwenhuizen <bas at basnieuwenhuizen.nl>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c       |  2 +-
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c      |  6 +-
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c      |  2 +-
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h      |  2 -
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c     |  6 +-
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 58 +++++++-------------
>>   6 files changed, 31 insertions(+), 45 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
>> index e8440d306496..025748e9c772 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
>> @@ -314,7 +314,7 @@ static void amdgpu_cs_get_threshold_for_moves(struct amdgpu_device *adev,
>>          }
>>
>>          total_vram = adev->gmc.real_vram_size - atomic64_read(&adev->vram_pin_size);
>> -       used_vram = amdgpu_vram_mgr_usage(&adev->mman.vram_mgr);
>> +       used_vram = ttm_resource_manager_usage(&adev->mman.vram_mgr.manager);
>>          free_vram = used_vram >= total_vram ? 0 : total_vram - used_vram;
>>
>>          spin_lock(&adev->mm_stats.lock);
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
>> index 9ff4aced5da7..0beab961b18b 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
>> @@ -678,7 +678,7 @@ int amdgpu_info_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
>>                  ui64 = atomic64_read(&adev->num_vram_cpu_page_faults);
>>                  return copy_to_user(out, &ui64, min(size, 8u)) ? -EFAULT : 0;
>>          case AMDGPU_INFO_VRAM_USAGE:
>> -               ui64 = amdgpu_vram_mgr_usage(&adev->mman.vram_mgr);
>> +               ui64 = ttm_resource_manager_usage(&adev->mman.vram_mgr.manager);
>>                  return copy_to_user(out, &ui64, min(size, 8u)) ? -EFAULT : 0;
>>          case AMDGPU_INFO_VIS_VRAM_USAGE:
>>                  ui64 = amdgpu_vram_mgr_vis_usage(&adev->mman.vram_mgr);
>> @@ -717,6 +717,8 @@ int amdgpu_info_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
>>                  struct drm_amdgpu_memory_info mem;
>>                  struct ttm_resource_manager *gtt_man =
>>                          &adev->mman.gtt_mgr.manager;
>> +               struct ttm_resource_manager *vram_man =
>> +                       &adev->mman.vram_mgr.manager;
>>
>>                  memset(&mem, 0, sizeof(mem));
>>                  mem.vram.total_heap_size = adev->gmc.real_vram_size;
>> @@ -724,7 +726,7 @@ int amdgpu_info_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
>>                          atomic64_read(&adev->vram_pin_size) -
>>                          AMDGPU_VM_RESERVED_VRAM;
>>                  mem.vram.heap_usage =
>> -                       amdgpu_vram_mgr_usage(&adev->mman.vram_mgr);
>> +                       ttm_resource_manager_usage(vram_man);
>>                  mem.vram.max_allocation = mem.vram.usable_heap_size * 3 / 4;
>>
>>                  mem.cpu_accessible_vram.total_heap_size =
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> index d178fbec7048..5859ed0552a4 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> @@ -1884,7 +1884,7 @@ void amdgpu_ttm_set_buffer_funcs_status(struct amdgpu_device *adev, bool enable)
>>                  size = adev->gmc.real_vram_size;
>>          else
>>                  size = adev->gmc.visible_vram_size;
>> -       man->size = size >> PAGE_SHIFT;
>> +       man->size = size;
>>          adev->mman.buffer_funcs_enabled = enable;
>>   }
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>> index 120b69ec9885..cbee84a77331 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>> @@ -44,7 +44,6 @@ struct amdgpu_vram_mgr {
>>          spinlock_t lock;
>>          struct list_head reservations_pending;
>>          struct list_head reserved_pages;
>> -       atomic64_t usage;
>>          atomic64_t vis_usage;
>>   };
>>
>> @@ -127,7 +126,6 @@ int amdgpu_vram_mgr_alloc_sgt(struct amdgpu_device *adev,
>>   void amdgpu_vram_mgr_free_sgt(struct device *dev,
>>                                enum dma_data_direction dir,
>>                                struct sg_table *sgt);
>> -uint64_t amdgpu_vram_mgr_usage(struct amdgpu_vram_mgr *mgr);
>>   uint64_t amdgpu_vram_mgr_vis_usage(struct amdgpu_vram_mgr *mgr);
>>   int amdgpu_vram_mgr_reserve_range(struct amdgpu_vram_mgr *mgr,
>>                                    uint64_t start, uint64_t size);
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
>> index 07bc0f504713..3a25dd220786 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
>> @@ -575,8 +575,10 @@ static int amdgpu_virt_write_vf2pf_data(struct amdgpu_device *adev)
>>          vf2pf_info->driver_cert = 0;
>>          vf2pf_info->os_info.all = 0;
>>
>> -       vf2pf_info->fb_usage = amdgpu_vram_mgr_usage(&adev->mman.vram_mgr) >> 20;
>> -       vf2pf_info->fb_vis_usage = amdgpu_vram_mgr_vis_usage(&adev->mman.vram_mgr) >> 20;
>> +       vf2pf_info->fb_usage =
>> +               ttm_resource_manager_usage(&adev->mman.vram_mgr.manager) >> 20;
>> +       vf2pf_info->fb_vis_usage =
>> +               amdgpu_vram_mgr_vis_usage(&adev->mman.vram_mgr) >> 20;
>>          vf2pf_info->fb_size = adev->gmc.real_vram_size >> 20;
>>          vf2pf_info->fb_vis_size = adev->gmc.visible_vram_size >> 20;
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>> index 7442095f089c..e50fe25fbcb8 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>> @@ -96,9 +96,9 @@ static ssize_t amdgpu_mem_info_vram_used_show(struct device *dev,
>>   {
>>          struct drm_device *ddev = dev_get_drvdata(dev);
>>          struct amdgpu_device *adev = drm_to_adev(ddev);
>> +       struct ttm_resource_manager *man = &adev->mman.vram_mgr.manager;
>>
>> -       return sysfs_emit(buf, "%llu\n",
>> -                         amdgpu_vram_mgr_usage(&adev->mman.vram_mgr));
>> +       return sysfs_emit(buf, "%llu\n", ttm_resource_manager_usage(man));
>>   }
>>
>>   /**
>> @@ -253,7 +253,9 @@ static void amdgpu_vram_mgr_do_reserve(struct ttm_resource_manager *man)
>>
>>                  vis_usage = amdgpu_vram_mgr_vis_size(adev, &rsv->mm_node);
>>                  atomic64_add(vis_usage, &mgr->vis_usage);
>> -               atomic64_add(rsv->mm_node.size << PAGE_SHIFT, &mgr->usage);
>> +               spin_lock(&man->bdev->lru_lock);
>> +               man->usage += rsv->mm_node.size << PAGE_SHIFT;
>> +               spin_unlock(&man->bdev->lru_lock);
>>                  list_move(&rsv->node, &mgr->reserved_pages);
>>          }
>>   }
>> @@ -378,19 +380,13 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
>>
>>          lpfn = place->lpfn;
>>          if (!lpfn)
>> -               lpfn = man->size;
>> +               lpfn = man->size >> PAGE_SHIFT;
>>
>>          max_bytes = adev->gmc.mc_vram_size;
>>          if (tbo->type != ttm_bo_type_kernel)
>>                  max_bytes -= AMDGPU_VM_RESERVED_VRAM;
>>
>> -       /* bail out quickly if there's likely not enough VRAM for this BO */
>>          mem_bytes = tbo->base.size;
>> -       if (atomic64_add_return(mem_bytes, &mgr->usage) > max_bytes) {
>> -               r = -ENOSPC;
>> -               goto error_sub;
>> -       }
>> -
>>          if (place->flags & TTM_PL_FLAG_CONTIGUOUS) {
>>                  pages_per_node = ~0ul;
>>                  num_nodes = 1;
>> @@ -408,13 +404,17 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
>>
>>          node = kvmalloc(struct_size(node, mm_nodes, num_nodes),
>>                          GFP_KERNEL | __GFP_ZERO);
>> -       if (!node) {
>> -               r = -ENOMEM;
>> -               goto error_sub;
>> -       }
>> +       if (!node)
>> +               return -ENOMEM;
>>
>>          ttm_resource_init(tbo, place, &node->base);
>>
>> +       /* bail out quickly if there's likely not enough VRAM for this BO */
>> +       if (ttm_resource_manager_usage(man) > max_bytes) {
>> +               r = -ENOSPC;
>> +               goto error_fini;
>> +       }
>> +
>>          mode = DRM_MM_INSERT_BEST;
>>          if (place->flags & TTM_PL_FLAG_TOPDOWN)
>>                  mode = DRM_MM_INSERT_HIGH;
>> @@ -472,11 +472,10 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
>>          while (i--)
>>                  drm_mm_remove_node(&node->mm_nodes[i]);
>>          spin_unlock(&mgr->lock);
>> +error_fini:
>>          ttm_resource_fini(man, &node->base);
>>          kvfree(node);
>>
>> -error_sub:
>> -       atomic64_sub(mem_bytes, &mgr->usage);
>>          return r;
>>   }
>>
>> @@ -494,7 +493,7 @@ static void amdgpu_vram_mgr_del(struct ttm_resource_manager *man,
>>          struct ttm_range_mgr_node *node = to_ttm_range_mgr_node(res);
>>          struct amdgpu_vram_mgr *mgr = to_vram_mgr(man);
>>          struct amdgpu_device *adev = to_amdgpu_device(mgr);
>> -       uint64_t usage = 0, vis_usage = 0;
>> +       uint64_t vis_usage = 0;
>>          unsigned i, pages;
>>
>>          spin_lock(&mgr->lock);
>> @@ -503,13 +502,11 @@ static void amdgpu_vram_mgr_del(struct ttm_resource_manager *man,
>>                  struct drm_mm_node *mm = &node->mm_nodes[i];
>>
>>                  drm_mm_remove_node(mm);
>> -               usage += mm->size << PAGE_SHIFT;
>>                  vis_usage += amdgpu_vram_mgr_vis_size(adev, mm);
>>          }
>>          amdgpu_vram_mgr_do_reserve(man);
>>          spin_unlock(&mgr->lock);
>>
>> -       atomic64_sub(usage, &mgr->usage);
>>          atomic64_sub(vis_usage, &mgr->vis_usage);
>>
>>          ttm_resource_fini(man, res);
>> @@ -627,18 +624,6 @@ void amdgpu_vram_mgr_free_sgt(struct device *dev,
>>          kfree(sgt);
>>   }
>>
>> -/**
>> - * amdgpu_vram_mgr_usage - how many bytes are used in this domain
>> - *
>> - * @mgr: amdgpu_vram_mgr pointer
>> - *
>> - * Returns how many bytes are used in this domain.
>> - */
>> -uint64_t amdgpu_vram_mgr_usage(struct amdgpu_vram_mgr *mgr)
>> -{
>> -       return atomic64_read(&mgr->usage);
>> -}
>> -
>>   /**
>>    * amdgpu_vram_mgr_vis_usage - how many bytes are used in the visible part
>>    *
>> @@ -664,13 +649,12 @@ static void amdgpu_vram_mgr_debug(struct ttm_resource_manager *man,
>>   {
>>          struct amdgpu_vram_mgr *mgr = to_vram_mgr(man);
>>
>> +       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);
>> -
>> -       drm_printf(printer, "man size:%llu pages, ram usage:%lluMB, vis usage:%lluMB\n",
>> -                  man->size, amdgpu_vram_mgr_usage(mgr) >> 20,
>> -                  amdgpu_vram_mgr_vis_usage(mgr) >> 20);
>>   }
>>
>>   static const struct ttm_resource_manager_func amdgpu_vram_mgr_func = {
>> @@ -692,11 +676,11 @@ int amdgpu_vram_mgr_init(struct amdgpu_device *adev)
>>          struct ttm_resource_manager *man = &mgr->manager;
>>
>>          ttm_resource_manager_init(man, &adev->mman.bdev,
>> -                                 adev->gmc.real_vram_size >> PAGE_SHIFT);
>> +                                 adev->gmc.real_vram_size);
> The kernel-doc for ttm_resource_manager_init() says that size is in
> page units, should we tweak that to say that it's driver defined or
> something?

Good point.

> Also amdgpu_bo_validate_size() looks like it is still expecting page
> units for man->size? Perhaps I'm looking at the wrong tree.

Looks like I missed that one. Thanks for the review, going to fix that 
one as well.

Regards,
Christian.

>
>>          man->func = &amdgpu_vram_mgr_func;
>>
>> -       drm_mm_init(&mgr->mm, 0, man->size);
>> +       drm_mm_init(&mgr->mm, 0, man->size >> PAGE_SHIFT);
>>          spin_lock_init(&mgr->lock);
>>          INIT_LIST_HEAD(&mgr->reservations_pending);
>>          INIT_LIST_HEAD(&mgr->reserved_pages);
>> --
>> 2.25.1
>>



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