[PATCH v3 4/5] drm/amdgpu: switch GPU workload profile

[Michel Dänzer]

On 2022-09-27 13:47, Sharma, Shashank wrote:
> On 9/27/2022 12:03 PM, Lazar, Lijo wrote:
>> On 9/27/2022 3:10 AM, Shashank Sharma wrote:
>>> This patch and switches the GPU workload based profile based
>>> on the workload hint information saved in the workload context.
>>> The workload profile is reset to NONE when the job is done.
>>>
>>> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
>>> Signed-off-by: Shashank Sharma <shashank.sharma at amd.com>
>>> ---
>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c           |  2 ++
>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_ctx_workload.c |  4 ----
>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_job.c          | 15 +++++++++++++++
>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_job.h          |  3 +++
>>>   4 files changed, 20 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
>>> index b7bae833c804..de906a42144f 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
>>> @@ -237,6 +237,8 @@ static int amdgpu_cs_parser_init(struct amdgpu_cs_parser *p, union drm_amdgpu_cs
>>>           goto free_all_kdata;
>>>       }
>>> +    p->job->workload_mode = p->ctx->workload_mode;
>>> +
>>>       if (p->uf_entry.tv.bo)
>>>           p->job->uf_addr = uf_offset;
>>>       kvfree(chunk_array);
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx_workload.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx_workload.c
>>> index a11cf29bc388..625114804121 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx_workload.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx_workload.c
>>> @@ -55,15 +55,11 @@ int amdgpu_set_workload_profile(struct amdgpu_device *adev,
>>>       mutex_lock(&adev->pm.smu_workload_lock);
>>> -    if (adev->pm.workload_mode == hint)
>>> -        goto unlock;
>>> -
>>
>> What is the expectation when a GFX job + VCN job together (or in general two jobs running in separate schedulers) and each prefers a different workload type? FW will switch as requested.
> 
> Well, I guess the last switched mode will take over. Do note that like most of the PM features, the real benefit of power profiles can be seen with consistant and similar workloads running for some time (Like gaming, video playback etc).

Not sure how that's supposed to work on a general purpose system, where there are always expected to be multiple processes (one of which being the display server) using the GPU for different workloads.

Even in special cases there may be multiple different kinds of workloads constantly being used at the same time, e.g. a fullscreen game with live streaming / recording using VCN.


Have you guys considered letting the display server (DRM master) choose the profile instead?


-- 
Earthling Michel Dänzer            |                  https://redhat.com
Libre software enthusiast          |         Mesa and Xwayland developer