Am 23.07.24 um 05:05 schrieb ZhenGuo Yin:
[Why]
Page table of compute VM in the VRAM will lost after gpu reset.
VRAM won't be restored since compute VM has no shadows.
[How]
Use higher 32-bit of vm->generation to record a vram_lost_counter.
Reset the VM state machine when vm->genertaion is not equal to
re-generation token.
v2: Check vm->generation instead of calling drm_sched_entity_error
in amdgpu_vm_validate.
I've just double checked the logic again and as far as I can see this
patch here is still completely superfluous.
When VRAM is lost any submission using the VM entity will fail and so
result in a new page table generation.
What isn't handled are CPU based page table updates, but for those we
could potentially change the condition inside the CPU page tables code.
Regards,
Christian.
Signed-off-by: ZhenGuo Yin <zhenguo.yin@xxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 3abfa66d72a2..9e2f84c166e7 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -434,7 +434,7 @@ uint64_t amdgpu_vm_generation(struct amdgpu_device *adev, struct amdgpu_vm *vm)
if (!vm)
return result;
- result += vm->generation;
+ result += (vm->generation & 0xFFFFFFFF);
/* Add one if the page tables will be re-generated on next CS */
if (drm_sched_entity_error(&vm->delayed))
++result;
@@ -467,9 +467,12 @@ int amdgpu_vm_validate(struct amdgpu_device *adev, struct amdgpu_vm *vm,
struct amdgpu_bo *shadow;
struct amdgpu_bo *bo;
int r;
+ uint32_t vram_lost_counter = atomic_read(&adev->vram_lost_counter);
- if (drm_sched_entity_error(&vm->delayed)) {
- ++vm->generation;
+ if (vm->generation != amdgpu_vm_generation(adev, vm)) {
+ if (drm_sched_entity_error(&vm->delayed))
+ ++vm->generation;
+ vm->generation = (u64)vram_lost_counter << 32 | (vm->generation & 0xFFFFFFFF);
amdgpu_vm_bo_reset_state_machine(vm);
amdgpu_vm_fini_entities(vm);
r = amdgpu_vm_init_entities(adev, vm);
@@ -2439,7 +2442,7 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
vm->last_update = dma_fence_get_stub();
vm->last_unlocked = dma_fence_get_stub();
vm->last_tlb_flush = dma_fence_get_stub();
- vm->generation = 0;
+ vm->generation = (u64)atomic_read(&adev->vram_lost_counter) << 32;
mutex_init(&vm->eviction_lock);
vm->evicting = false;
