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

Matthew Auld matthew.william.auld at gmail.com
Wed Feb 9 09:53:08 UTC 2022


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?

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

>
>         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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