On 9/27/2022 10:40 PM, Alex Deucher wrote:
On Tue, Sep 27, 2022 at 11:38 AM Sharma, Shashank
<shashank.sharma@xxxxxxx> wrote:
On 9/27/2022 5:23 PM, Felix Kuehling wrote:
Am 2022-09-27 um 10:58 schrieb Sharma, Shashank:
Hello Felix,
Thank for the review comments.
On 9/27/2022 4:48 PM, Felix Kuehling wrote:
Am 2022-09-27 um 02:12 schrieb Christian König:
Am 26.09.22 um 23:40 schrieb Shashank Sharma:
This patch switches the GPU workload mode to/from
compute mode, while submitting compute workload.
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Shashank Sharma <shashank.sharma@xxxxxxx>
Feel free to add my acked-by, but Felix should probably take a look
as well.
This look OK purely from a compute perspective. But I'm concerned
about the interaction of compute with graphics or multiple graphics
contexts submitting work concurrently. They would constantly override
or disable each other's workload hints.
For example, you have an amdgpu_ctx with
AMDGPU_CTX_WORKLOAD_HINT_COMPUTE (maybe Vulkan compute) and a KFD
process that also wants the compute profile. Those could be different
processes belonging to different users. Say, KFD enables the compute
profile first. Then the graphics context submits a job. At the start
of the job, the compute profile is enabled. That's a no-op because
KFD already enabled the compute profile. When the job finishes, it
disables the compute profile for everyone, including KFD. That's
unexpected.
In this case, it will not disable the compute profile, as the
reference counter will not be zero. The reset_profile() will only act
if the reference counter is 0.
OK, I missed the reference counter.
But I would be happy to get any inputs about a policy which can be
more sustainable and gets better outputs, for example:
- should we not allow a profile change, if a PP mode is already
applied and keep it Early bird basis ?
For example: Policy A
- Job A sets the profile to compute
- Job B tries to set profile to 3D, but we do not allow it as job A is
not finished it yet.
Or Policy B: Current one
- Job A sets the profile to compute
- Job B tries to set profile to 3D, and we allow it. Job A also runs
in PP 3D
- Job B finishes, but does not reset PP as reference count is not zero
due to compute
- Job A finishes, profile reset to NONE
I think this won't work. As I understand it, the
amdgpu_dpm_switch_power_profile enables and disables individual
profiles. Disabling the 3D profile doesn't disable the compute profile
at the same time. I think you'll need one refcount per profile.
Regards,
Felix
Thanks, This is exactly what I was looking for, I think Alex's initial
idea was around it, but I was under the assumption that there is only
one HW profile in SMU which keeps on getting overwritten. This can solve
our problems, as I can create an array of reference counters, and will
disable only the profile whose reference counter goes 0.
It's been a while since I paged any of this code into my head, but I
believe the actual workload message in the SMU is a mask where you can
specify multiple workload types at the same time and the SMU will
arbitrate between them internally. E.g., the most aggressive one will
be selected out of the ones specified. I think in the driver we just
set one bit at a time using the current interface. It might be better
to change the interface and just ref count the hint types and then
when we call the set function look at the ref counts for each hint
type and set the mask as appropriate.
Alex
Hey Alex,
Thanks for your comment, if that is the case, this current patch series
works straight forward, and no changes would be required. Please let me
know if my understanding is correct:
Assumption: Order of aggression: 3D > Media > Compute
- Job 1: Requests mode compute: PP changed to compute, ref count 1
- Job 2: Requests mode media: PP changed to media, ref count 2
- Job 3: requests mode 3D: PP changed to 3D, ref count 3
- Job 1 finishes, downs ref count to 2, doesn't reset the PP as ref > 0,
PP still 3D
- Job 3 finishes, downs ref count to 1, doesn't reset the PP as ref > 0,
PP still 3D
- Job 2 finishes, downs ref count to 0, PP changed to NONE,
In this way, every job will be operating in the Power profile of desired
aggression or higher, and this API guarantees the execution at-least in
the desired power profile.
- Shashank
- Shashank
Or anything else ?
REgards
Shashank
Or you have multiple VCN contexts. When context1 finishes a job, it
disables the VIDEO profile. But context2 still has a job on the other
VCN engine and wants the VIDEO profile to still be enabled.
Regards,
Felix
Christian.
---
drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
index 5e53a5293935..1caed319a448 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
@@ -34,6 +34,7 @@
#include "amdgpu_ras.h"
#include "amdgpu_umc.h"
#include "amdgpu_reset.h"
+#include "amdgpu_ctx_workload.h"
/* Total memory size in system memory and all GPU VRAM. Used to
* estimate worst case amount of memory to reserve for page tables
@@ -703,9 +704,16 @@ int amdgpu_amdkfd_submit_ib(struct
amdgpu_device *adev,
void amdgpu_amdkfd_set_compute_idle(struct amdgpu_device *adev,
bool idle)
{
- amdgpu_dpm_switch_power_profile(adev,
- PP_SMC_POWER_PROFILE_COMPUTE,
- !idle);
+ int ret;
+
+ if (idle)
+ ret = amdgpu_clear_workload_profile(adev,
AMDGPU_CTX_WORKLOAD_HINT_COMPUTE);
+ else
+ ret = amdgpu_set_workload_profile(adev,
AMDGPU_CTX_WORKLOAD_HINT_COMPUTE);
+
+ if (ret)
+ drm_warn(&adev->ddev, "Failed to %s power profile to
compute mode\n",
+ idle ? "reset" : "set");
}
bool amdgpu_amdkfd_is_kfd_vmid(struct amdgpu_device *adev, u32
vmid)
