[PATCH v3 1/5] drm/amdgpu: add UAPI for workload hints to ctx ioctl
Sharma, Shashank
Shashank.Sharma at amd.com
Wed Mar 22 14:38:47 UTC 2023
[AMD Official Use Only - General]
From the exposed workload hints:
+#define AMDGPU_CTX_WORKLOAD_HINT_NONE
+#define AMDGPU_CTX_WORKLOAD_HINT_3D
+#define AMDGPU_CTX_WORKLOAD_HINT_VIDEO
+#define AMDGPU_CTX_WORKLOAD_HINT_VR
+#define AMDGPU_CTX_WORKLOAD_HINT_COMPUTE
I guess the only option which we do not know how to use is HINT_VR, everything else is known. I find it a limitation of the stack that we can’t differentiate between a VR workload Vs 3D, coz at some time we might have to give high privilege or special attention to it when VR becomes more demanding, but for now, I can remove this one option from the patch:
+#define AMDGPU_CTX_WORKLOAD_HINT_VR
Regards
Shashank
From: Koenig, Christian <Christian.Koenig at amd.com>
Sent: 22 March 2023 15:29
To: Marek Olšák <maraeo at gmail.com>
Cc: Christian König <ckoenig.leichtzumerken at gmail.com>; Sharma, Shashank <Shashank.Sharma at amd.com>; Deucher, Alexander <Alexander.Deucher at amd.com>; Somalapuram, Amaranath <Amaranath.Somalapuram at amd.com>; amd-gfx at lists.freedesktop.org
Subject: Re: [PATCH v3 1/5] drm/amdgpu: add UAPI for workload hints to ctx ioctl
Well that sounds like being able to optionally set it after context creation is actually the right approach.
VA-API could set it as soon as we know that this is a video codec application.
Vulkan can set it depending on what features are used by the application.
But yes, Shashank (or whoever requested that) should come up with some code for Mesa to actually use it. Otherwise we don't have the justification to push it into the kernel driver.
Christian.
Am 22.03.23 um 15:24 schrieb Marek Olšák:
The hint is static per API (one of graphics, video, compute, unknown). In the case of Vulkan, which exposes all queues, the hint is unknown, so Vulkan won't use it. (or make it based on the queue being used and not the uapi context state) GL won't use it because the default hint is already 3D. That makes VAAPI the only user that only sets the hint once, and maybe it's not worth even adding this uapi just for VAAPI.
Marek
On Wed, Mar 22, 2023 at 10:08 AM Christian König <christian.koenig at amd.com<mailto:christian.koenig at amd.com>> wrote:
Well completely agree that we shouldn't have unused API. That's why I said we should remove the getting the hint from the UAPI.
But what's wrong with setting it after creating the context? Don't you know enough about the use case? I need to understand the background a bit better here.
Christian.
Am 22.03.23 um 15:05 schrieb Marek Olšák:
The option to change the hint after context creation and get the hint would be unused uapi, and AFAIK we are not supposed to add unused uapi. What I asked is to change it to a uapi that userspace will actually use.
Marek
On Tue, Mar 21, 2023 at 9:54 AM Christian König <ckoenig.leichtzumerken at gmail.com<mailto:ckoenig.leichtzumerken at gmail.com>> wrote:
Yes, I would like to avoid having multiple code paths for context creation.
Setting it later on should be equally to specifying it on creation since we only need it during CS.
Regards,
Christian.
Am 21.03.23 um 14:00 schrieb Sharma, Shashank:
[AMD Official Use Only - General]
When we started this patch series, the workload hint was a part of the ctx_flag only,
But we changed that after the design review, to make it more like how we are handling PSTATE.
Details:
https://patchwork.freedesktop.org/patch/496111/
Regards
Shashank
From: Marek Olšák <maraeo at gmail.com><mailto:maraeo at gmail.com>
Sent: 21 March 2023 04:05
To: Sharma, Shashank <Shashank.Sharma at amd.com><mailto:Shashank.Sharma at amd.com>
Cc: amd-gfx at lists.freedesktop.org<mailto:amd-gfx at lists.freedesktop.org>; Deucher, Alexander <Alexander.Deucher at amd.com><mailto:Alexander.Deucher at amd.com>; Somalapuram, Amaranath <Amaranath.Somalapuram at amd.com><mailto:Amaranath.Somalapuram at amd.com>; Koenig, Christian <Christian.Koenig at amd.com><mailto:Christian.Koenig at amd.com>
Subject: Re: [PATCH v3 1/5] drm/amdgpu: add UAPI for workload hints to ctx ioctl
I think we should do it differently because this interface will be mostly unused by open source userspace in its current form.
Let's set the workload hint in drm_amdgpu_ctx_in::flags, and that will be immutable for the lifetime of the context. No other interface is needed.
Marek
On Mon, Sep 26, 2022 at 5:41 PM Shashank Sharma <shashank.sharma at amd.com<mailto:shashank.sharma at amd.com>> wrote:
Allow the user to specify a workload hint to the kernel.
We can use these to tweak the dpm heuristics to better match
the workload for improved performance.
V3: Create only set() workload UAPI (Christian)
Signed-off-by: Alex Deucher <alexander.deucher at amd.com<mailto:alexander.deucher at amd.com>>
Signed-off-by: Shashank Sharma <shashank.sharma at amd.com<mailto:shashank.sharma at amd.com>>
---
include/uapi/drm/amdgpu_drm.h | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/include/uapi/drm/amdgpu_drm.h b/include/uapi/drm/amdgpu_drm.h
index c2c9c674a223..23d354242699 100644
--- a/include/uapi/drm/amdgpu_drm.h
+++ b/include/uapi/drm/amdgpu_drm.h
@@ -212,6 +212,7 @@ union drm_amdgpu_bo_list {
#define AMDGPU_CTX_OP_QUERY_STATE2 4
#define AMDGPU_CTX_OP_GET_STABLE_PSTATE 5
#define AMDGPU_CTX_OP_SET_STABLE_PSTATE 6
+#define AMDGPU_CTX_OP_SET_WORKLOAD_PROFILE 7
/* GPU reset status */
#define AMDGPU_CTX_NO_RESET 0
@@ -252,6 +253,17 @@ union drm_amdgpu_bo_list {
#define AMDGPU_CTX_STABLE_PSTATE_MIN_MCLK 3
#define AMDGPU_CTX_STABLE_PSTATE_PEAK 4
+/* GPU workload hints, flag bits 8-15 */
+#define AMDGPU_CTX_WORKLOAD_HINT_SHIFT 8
+#define AMDGPU_CTX_WORKLOAD_HINT_MASK (0xff << AMDGPU_CTX_WORKLOAD_HINT_SHIFT)
+#define AMDGPU_CTX_WORKLOAD_HINT_NONE (0 << AMDGPU_CTX_WORKLOAD_HINT_SHIFT)
+#define AMDGPU_CTX_WORKLOAD_HINT_3D (1 << AMDGPU_CTX_WORKLOAD_HINT_SHIFT)
+#define AMDGPU_CTX_WORKLOAD_HINT_VIDEO (2 << AMDGPU_CTX_WORKLOAD_HINT_SHIFT)
+#define AMDGPU_CTX_WORKLOAD_HINT_VR (3 << AMDGPU_CTX_WORKLOAD_HINT_SHIFT)
+#define AMDGPU_CTX_WORKLOAD_HINT_COMPUTE (4 << AMDGPU_CTX_WORKLOAD_HINT_SHIFT)
+#define AMDGPU_CTX_WORKLOAD_HINT_MAX AMDGPU_CTX_WORKLOAD_HINT_COMPUTE
+#define AMDGPU_CTX_WORKLOAD_INDEX(n) (n >> AMDGPU_CTX_WORKLOAD_HINT_SHIFT)
+
struct drm_amdgpu_ctx_in {
/** AMDGPU_CTX_OP_* */
__u32 op;
@@ -281,6 +293,11 @@ union drm_amdgpu_ctx_out {
__u32 flags;
__u32 _pad;
} pstate;
+
+ struct {
+ __u32 flags;
+ __u32 _pad;
+ } workload;
};
union drm_amdgpu_ctx {
--
2.34.1
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/amd-gfx/attachments/20230322/b1b7f8dc/attachment-0001.htm>
More information about the amd-gfx
mailing list