[PATCH 05/12] drm/amdgpu: Send no-retry XNACK for all fault types

[Alex Deucher]

On Wed, Jul 12, 2017 at 1:40 AM, Felix Kuehling <felix.kuehling at amd.com> wrote:
> Any comments?
>
> I believe this is a nice stability improvement. In case of VM faults
> they don't take down the whole GPU with an interrupt storm. With KFD we
> can recover without a GPU reset in many cases just by unmapping the
> offending process' queues.

Will this cause any problems with enabling recoverable page faults
later?  If not,
Acked-by: Alex Deucher <alexander.deucher at amd.com>

>
> Regards,
>   Felix
>
>
> On 17-07-03 05:11 PM, Felix Kuehling wrote:
>> From: Jay Cornwall <Jay.Cornwall at amd.com>
>>
>> A subset of VM fault types currently send retry XNACK to the client.
>> This causes a storm of interrupts from the VM to the host.
>>
>> Until the storm is throttled by other means send no-retry XNACK for
>> all fault types instead. No change in behavior to the client which
>> will stall indefinitely with the current configuration in any case.
>> Improves system stability under GC or MMHUB faults.
>>
>> Signed-off-by: Jay Cornwall <Jay.Cornwall at amd.com>
>> Reviewed-by: Felix Kuehling <Felix.Kuehling at amd.com>
>> ---
>>  drivers/gpu/drm/amd/amdgpu/gfxhub_v1_0.c | 3 +++
>>  drivers/gpu/drm/amd/amdgpu/mmhub_v1_0.c  | 3 +++
>>  2 files changed, 6 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/gfxhub_v1_0.c b/drivers/gpu/drm/amd/amdgpu/gfxhub_v1_0.c
>> index a42f483..f957b18 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/gfxhub_v1_0.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/gfxhub_v1_0.c
>> @@ -206,6 +206,9 @@ static void gfxhub_v1_0_setup_vmid_config(struct amdgpu_device *adev)
>>               tmp = REG_SET_FIELD(tmp, VM_CONTEXT1_CNTL,
>>                               PAGE_TABLE_BLOCK_SIZE,
>>                               adev->vm_manager.block_size - 9);
>> +             /* Send no-retry XNACK on fault to suppress VM fault storm. */
>> +             tmp = REG_SET_FIELD(tmp, VM_CONTEXT1_CNTL,
>> +                                 RETRY_PERMISSION_OR_INVALID_PAGE_FAULT, 0);
>>               WREG32_SOC15_OFFSET(GC, 0, mmVM_CONTEXT1_CNTL, i, tmp);
>>               WREG32_SOC15_OFFSET(GC, 0, mmVM_CONTEXT1_PAGE_TABLE_START_ADDR_LO32, i*2, 0);
>>               WREG32_SOC15_OFFSET(GC, 0, mmVM_CONTEXT1_PAGE_TABLE_START_ADDR_HI32, i*2, 0);
>> diff --git a/drivers/gpu/drm/amd/amdgpu/mmhub_v1_0.c b/drivers/gpu/drm/amd/amdgpu/mmhub_v1_0.c
>> index 01918dc..b760018 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/mmhub_v1_0.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/mmhub_v1_0.c
>> @@ -222,6 +222,9 @@ static void mmhub_v1_0_setup_vmid_config(struct amdgpu_device *adev)
>>               tmp = REG_SET_FIELD(tmp, VM_CONTEXT1_CNTL,
>>                               PAGE_TABLE_BLOCK_SIZE,
>>                               adev->vm_manager.block_size - 9);
>> +             /* Send no-retry XNACK on fault to suppress VM fault storm. */
>> +             tmp = REG_SET_FIELD(tmp, VM_CONTEXT1_CNTL,
>> +                                 RETRY_PERMISSION_OR_INVALID_PAGE_FAULT, 0);
>>               WREG32_SOC15_OFFSET(MMHUB, 0, mmVM_CONTEXT1_CNTL, i, tmp);
>>               WREG32_SOC15_OFFSET(MMHUB, 0, mmVM_CONTEXT1_PAGE_TABLE_START_ADDR_LO32, i*2, 0);
>>               WREG32_SOC15_OFFSET(MMHUB, 0, mmVM_CONTEXT1_PAGE_TABLE_START_ADDR_HI32, i*2, 0);
>
> _______________________________________________
> amd-gfx mailing list
> amd-gfx at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/amd-gfx