[RFC PATCH v2] drm/amdgpu: Remove kfd eviction fence before release bo
Pan, Xinhui
Xinhui.Pan at amd.com
Fri Feb 7 13:42:57 UTC 2020
No need to trigger eviction as the memory mapping will not be used anymore.
All pt/pd bos share same resv, hence the same shared eviction fence. Everytime page table is freed, the fence will be signled and that cuases kfd unexcepted evictions.
Signed-off-by: xinhui pab <xinhui.pan at example.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h | 1 +
.../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 78 ++++++++++++++++++-
drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 10 ++-
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 5 +-
drivers/gpu/drm/ttm/ttm_bo.c | 38 +++++----
5 files changed, 111 insertions(+), 21 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
index 47b0f2957d1f..265b1ed7264c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
@@ -96,6 +96,7 @@ struct amdgpu_amdkfd_fence *amdgpu_amdkfd_fence_create(u64 context,
struct mm_struct *mm);
bool amdkfd_fence_check_mm(struct dma_fence *f, struct mm_struct *mm);
struct amdgpu_amdkfd_fence *to_amdgpu_amdkfd_fence(struct dma_fence *f);
+int amdgpu_amdkfd_remove_fence_on_pt_pd_bos(struct amdgpu_bo *bo);
struct amdkfd_process_info {
/* List head of all VMs that belong to a KFD process */
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index ef721cb65868..11315095c29b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -223,7 +223,7 @@ void amdgpu_amdkfd_unreserve_memory_limit(struct amdgpu_bo *bo)
static int amdgpu_amdkfd_remove_eviction_fence(struct amdgpu_bo *bo,
struct amdgpu_amdkfd_fence *ef)
{
- struct dma_resv *resv = bo->tbo.base.resv;
+ struct dma_resv *resv = &bo->tbo.base._resv;
struct dma_resv_list *old, *new;
unsigned int i, j, k;
@@ -276,6 +276,78 @@ static int amdgpu_amdkfd_remove_eviction_fence(struct amdgpu_bo *bo,
return 0;
}
+int amdgpu_amdkfd_remove_fence_on_pt_pd_bos(struct amdgpu_bo *bo)
+{
+ struct amdgpu_vm_bo_base *vm_bo = bo->vm_bo;
+ struct amdgpu_vm *vm;
+ struct amdkfd_process_info *info;
+ struct amdgpu_amdkfd_fence *ef;
+ struct amdgpu_bo *parent;
+ int locked;
+ int ret;
+ struct ttm_bo_global *glob = &ttm_bo_glob;
+
+ if (vm_bo == NULL)
+ return 0;
+
+ /* Page table bo has a reference of the parent bo.
+ * BO itself can't guarntee the vm it points to is alive.
+ * for example, VM is going to free page tables, and the pt/pd bo might be
+ * freed by a workqueue. In that case, the vm might be freed already,
+ * leaving the bo->vm_bo points to vm.root.
+ *
+ * so to avoid that, when kfd free its vms,
+ * 1) set vm->process_info to NULL if this is the last vm.
+ * 2) set root_bo->vm_bo to NULL.
+ *
+ * but there are still races, just like
+ * cpu 1 cpu 2
+ * !vm_bo
+ * ->info = NULL
+ * free(info)
+ * ->vm_bo = NULL
+ * free (vm)
+ * info = vm->info //invalid vm
+ *
+ * So to avoid the race, use ttm_bo_glob lru_lock.
+ * generally speaking, adding a new lock is accceptable.
+ * But reusing this lock is simple.
+ */
+ parent = bo;
+ while (parent->parent)
+ parent = parent->parent;
+
+ spin_lock(&glob->lru_lock);
+ vm_bo = parent->vm_bo;
+ if (!vm_bo) {
+ spin_unlock(&glob->lru_lock);
+ return 0;
+ }
+
+ vm = vm_bo->vm;
+ if (!vm) {
+ spin_unlock(&glob->lru_lock);
+ return 0;
+ }
+
+ info = vm->process_info;
+ if (!info || !info->eviction_fence) {
+ spin_unlock(&glob->lru_lock);
+ return 0;
+ }
+
+ ef = container_of(dma_fence_get(&info->eviction_fence->base),
+ struct amdgpu_amdkfd_fence, base);
+ spin_unlock(&glob->lru_lock);
+
+ locked = dma_resv_trylock(&bo->tbo.base._resv);
+ ret = amdgpu_amdkfd_remove_eviction_fence(bo, ef);
+ dma_fence_put(&ef->base);
+ if (locked)
+ dma_resv_unlock(&bo->tbo.base._resv);
+ return ret;
+}
+
static int amdgpu_amdkfd_bo_validate(struct amdgpu_bo *bo, uint32_t domain,
bool wait)
{
@@ -1030,6 +1102,7 @@ void amdgpu_amdkfd_gpuvm_destroy_cb(struct amdgpu_device *adev,
{
struct amdkfd_process_info *process_info = vm->process_info;
struct amdgpu_bo *pd = vm->root.base.bo;
+ struct ttm_bo_global *glob = &ttm_bo_glob;
if (!process_info)
return;
@@ -1051,6 +1124,9 @@ void amdgpu_amdkfd_gpuvm_destroy_cb(struct amdgpu_device *adev,
WARN_ON(!list_empty(&process_info->userptr_valid_list));
WARN_ON(!list_empty(&process_info->userptr_inval_list));
+ spin_lock(&glob->lru_lock);
+ vm->process_info = NULL;
+ spin_unlock(&glob->lru_lock);
dma_fence_put(&process_info->eviction_fence->base);
cancel_delayed_work_sync(&process_info->restore_userptr_work);
put_pid(process_info->pid);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
index 6f60a581e3ba..6ad12298fa84 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
@@ -1307,19 +1307,23 @@ void amdgpu_bo_release_notify(struct ttm_buffer_object *bo)
if (abo->kfd_bo)
amdgpu_amdkfd_unreserve_memory_limit(abo);
+ amdgpu_amdkfd_remove_fence_on_pt_pd_bos(abo);
+ abo->vm_bo = NULL;
+
if (bo->mem.mem_type != TTM_PL_VRAM || !bo->mem.mm_node ||
!(abo->flags & AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE))
return;
- dma_resv_lock(bo->base.resv, NULL);
+ /* Only kfd bo wipe vram on release. The resv is &_resv. */
+ dma_resv_lock(&bo->base._resv, NULL);
- r = amdgpu_fill_buffer(abo, AMDGPU_POISON, bo->base.resv, &fence);
+ r = amdgpu_fill_buffer(abo, AMDGPU_POISON, &bo->base._resv, &fence);
if (!WARN_ON(r)) {
amdgpu_bo_fence(abo, fence, false);
dma_fence_put(fence);
}
- dma_resv_unlock(bo->base.resv);
+ dma_resv_unlock(&bo->base._resv);
}
/**
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index cc56eaba1911..2b96447e30e5 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -945,7 +945,6 @@ static int amdgpu_vm_alloc_pts(struct amdgpu_device *adev,
static void amdgpu_vm_free_table(struct amdgpu_vm_pt *entry)
{
if (entry->base.bo) {
- entry->base.bo->vm_bo = NULL;
list_del(&entry->base.vm_status);
amdgpu_bo_unref(&entry->base.bo->shadow);
amdgpu_bo_unref(&entry->base.bo);
@@ -3074,6 +3073,7 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
struct amdgpu_bo_va_mapping *mapping, *tmp;
bool prt_fini_needed = !!adev->gmc.gmc_funcs->set_prt;
struct amdgpu_bo *root;
+ struct ttm_bo_global *glob = &ttm_bo_glob;
int i;
amdgpu_amdkfd_gpuvm_destroy_cb(adev, vm);
@@ -3105,6 +3105,9 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
}
amdgpu_vm_free_pts(adev, vm, NULL);
+ spin_lock(&glob->lru_lock);
+ root->vm_bo = NULL;
+ spin_unlock(&glob->lru_lock);
amdgpu_bo_unreserve(root);
amdgpu_bo_unref(&root);
WARN_ON(vm->root.base.bo);
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 1494aebb8128..706cd60eb9e0 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -429,8 +429,8 @@ static int ttm_bo_individualize_resv(struct ttm_buffer_object *bo)
BUG_ON(!dma_resv_trylock(&bo->base._resv));
r = dma_resv_copy_fences(&bo->base._resv, bo->base.resv);
- if (r)
- dma_resv_unlock(&bo->base._resv);
+
+ dma_resv_unlock(&bo->base._resv);
return r;
}
@@ -455,23 +455,19 @@ static void ttm_bo_flush_all_fences(struct ttm_buffer_object *bo)
}
}
-static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo)
+static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo, bool enqueue)
{
struct ttm_bo_device *bdev = bo->bdev;
int ret;
- ret = ttm_bo_individualize_resv(bo);
- if (ret) {
- /* Last resort, if we fail to allocate memory for the
- * fences block for the BO to become idle
- */
- dma_resv_wait_timeout_rcu(bo->base.resv, true, false,
- 30 * HZ);
- spin_lock(&ttm_bo_glob.lru_lock);
- goto error;
- }
-
spin_lock(&ttm_bo_glob.lru_lock);
+
+ if (enqueue)
+ goto queue;
+
+ if (bo->base.resv != &bo->base._resv)
+ BUG_ON(!dma_resv_trylock(&bo->base._resv));
+
ret = dma_resv_trylock(bo->base.resv) ? 0 : -EBUSY;
if (!ret) {
if (dma_resv_test_signaled_rcu(&bo->base._resv, true)) {
@@ -504,7 +500,7 @@ static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo)
dma_resv_unlock(&bo->base._resv);
}
-error:
+queue:
kref_get(&bo->list_kref);
list_add_tail(&bo->ddestroy, &bdev->ddestroy);
spin_unlock(&ttm_bo_glob.lru_lock);
@@ -655,6 +651,16 @@ static void ttm_bo_release(struct kref *kref)
container_of(kref, struct ttm_buffer_object, kref);
struct ttm_bo_device *bdev = bo->bdev;
struct ttm_mem_type_manager *man = &bdev->man[bo->mem.mem_type];
+ int ret;
+
+ ret = ttm_bo_individualize_resv(bo);
+ if (ret) {
+ /* Last resort, if we fail to allocate memory for the
+ * fences block for the BO to become idle
+ */
+ dma_resv_wait_timeout_rcu(bo->base.resv, true, false,
+ 30 * HZ);
+ }
if (bo->bdev->driver->release_notify)
bo->bdev->driver->release_notify(bo);
@@ -663,7 +669,7 @@ static void ttm_bo_release(struct kref *kref)
ttm_mem_io_lock(man, false);
ttm_mem_io_free_vm(bo);
ttm_mem_io_unlock(man);
- ttm_bo_cleanup_refs_or_queue(bo);
+ ttm_bo_cleanup_refs_or_queue(bo, !!ret);
kref_put(&bo->list_kref, ttm_bo_release_list);
}
--
2.17.1
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