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

Christian König <ckoenig.leichtzumerken@xxxxxxxxx> · Wed, 9 Feb 2022 13:09:04 +0100

Am 09.02.22 um 10:53 schrieb Matthew Auld:
On Wed, 9 Feb 2022 at 08:41, Christian König
<ckoenig.leichtzumerken@xxxxxxxxx> 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@xxxxxxx>
Tested-by: Bas Nieuwenhuizen <bas@xxxxxxxxxxxxxxxxxxx>
---
  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








