On Tue, Sep 24, 2024 at 4:54 AM Antonino Maniscalco <antomani103@xxxxxxxxx> wrote: > > On 9/20/24 7:09 PM, Akhil P Oommen wrote: > > On Wed, Sep 18, 2024 at 09:46:33AM +0200, Neil Armstrong wrote: > >> Hi, > >> > >> On 17/09/2024 13:14, Antonino Maniscalco wrote: > >>> This series implements preemption for A7XX targets, which allows the GPU to > >>> switch to an higher priority ring when work is pushed to it, reducing latency > >>> for high priority submissions. > >>> > >>> This series enables L1 preemption with skip_save_restore which requires > >>> the following userspace patches to function: > >>> > >>> https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30544 > >>> > >>> A flag is added to `msm_submitqueue_create` to only allow submissions > >>> from compatible userspace to be preempted, therefore maintaining > >>> compatibility. > >>> > >>> Preemption is currently only enabled by default on A750, it can be > >>> enabled on other targets through the `enable_preemption` module > >>> parameter. This is because more testing is required on other targets. > >>> > >>> For testing on other HW it is sufficient to set that parameter to a > >>> value of 1, then using the branch of mesa linked above, `TU_DEBUG=hiprio` > >>> allows to run any application as high priority therefore preempting > >>> submissions from other applications. > >>> > >>> The `msm_gpu_preemption_trigger` and `msm_gpu_preemption_irq` traces > >>> added in this series can be used to observe preemption's behavior as > >>> well as measuring preemption latency. > >>> > >>> Some commits from this series are based on a previous series to enable > >>> preemption on A6XX targets: > >>> > >>> https://lkml.kernel.org/1520489185-21828-1-git-send-email-smasetty@xxxxxxxxxxxxxx > >>> > >>> Signed-off-by: Antonino Maniscalco <antomani103@xxxxxxxxx> > >>> --- > >>> Changes in v4: > >>> - Added missing register in pwrup list > >>> - Removed and rearrange barriers > >>> - Renamed `skip_inline_wptr` to `restore_wptr` > >>> - Track ctx seqno per ring > >>> - Removed secure preempt context > >>> - NOP out postamble to disable it instantly > >>> - Only emit pwrup reglist once > >>> - Document bv_rptr_addr > >>> - Removed unused A6XX_PREEMPT_USER_RECORD_SIZE > >>> - Set name on preempt record buffer > >>> - Link to v3: https://lore.kernel.org/r/20240905-preemption-a750-t-v3-0-fd947699f7bc@xxxxxxxxx > >>> > >>> Changes in v3: > >>> - Added documentation about preemption > >>> - Use quirks to determine which target supports preemption > >>> - Add a module parameter to force disabling or enabling preemption > >>> - Clear postamble when profiling > >>> - Define A6XX_CP_CONTEXT_SWITCH_CNTL_LEVEL fields in a6xx.xml > >>> - Make preemption records MAP_PRIV > >>> - Removed user ctx record (NON_PRIV) and patch 2/9 as it's not needed > >>> anymore > >>> - Link to v2: https://lore.kernel.org/r/20240830-preemption-a750-t-v2-0-86aeead2cd80@xxxxxxxxx > >>> > >>> Changes in v2: > >>> - Added preept_record_size for X185 in PATCH 3/7 > >>> - Added patches to reset perf counters > >>> - Dropped unused defines > >>> - Dropped unused variable (fixes warning) > >>> - Only enable preemption on a750 > >>> - Reject MSM_SUBMITQUEUE_ALLOW_PREEMPT for unsupported targets > >>> - Added Akhil's Reviewed-By tags to patches 1/9,2/9,3/9 > >>> - Added Neil's Tested-By tags > >>> - Added explanation for UAPI changes in commit message > >>> - Link to v1: https://lore.kernel.org/r/20240815-preemption-a750-t-v1-0-7bda26c34037@xxxxxxxxx > >>> > >>> --- > >>> Antonino Maniscalco (11): > >>> drm/msm: Fix bv_fence being used as bv_rptr > >>> drm/msm/A6XX: Track current_ctx_seqno per ring > >>> drm/msm: Add a `preempt_record_size` field > >>> drm/msm: Add CONTEXT_SWITCH_CNTL bitfields > >>> drm/msm/A6xx: Implement preemption for A7XX targets > >>> drm/msm/A6xx: Sync relevant adreno_pm4.xml changes > >>> drm/msm/A6xx: Use posamble to reset counters on preemption > >>> drm/msm/A6xx: Add traces for preemption > >>> drm/msm/A6XX: Add a flag to allow preemption to submitqueue_create > >>> drm/msm/A6xx: Enable preemption for A750 > >>> Documentation: document adreno preemption > >>> > >>> Documentation/gpu/msm-preemption.rst | 98 +++++ > >>> drivers/gpu/drm/msm/Makefile | 1 + > >>> drivers/gpu/drm/msm/adreno/a2xx_gpu.c | 2 +- > >>> drivers/gpu/drm/msm/adreno/a3xx_gpu.c | 2 +- > >>> drivers/gpu/drm/msm/adreno/a4xx_gpu.c | 2 +- > >>> drivers/gpu/drm/msm/adreno/a5xx_gpu.c | 6 +- > >>> drivers/gpu/drm/msm/adreno/a6xx_catalog.c | 7 +- > >>> drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 325 ++++++++++++++- > >>> drivers/gpu/drm/msm/adreno/a6xx_gpu.h | 174 ++++++++ > >>> drivers/gpu/drm/msm/adreno/a6xx_preempt.c | 440 +++++++++++++++++++++ > >>> drivers/gpu/drm/msm/adreno/adreno_gpu.h | 9 +- > >>> drivers/gpu/drm/msm/msm_drv.c | 4 + > >>> drivers/gpu/drm/msm/msm_gpu.c | 2 +- > >>> drivers/gpu/drm/msm/msm_gpu.h | 11 - > >>> drivers/gpu/drm/msm/msm_gpu_trace.h | 28 ++ > >>> drivers/gpu/drm/msm/msm_ringbuffer.h | 18 + > >>> drivers/gpu/drm/msm/msm_submitqueue.c | 3 + > >>> drivers/gpu/drm/msm/registers/adreno/a6xx.xml | 7 +- > >>> .../gpu/drm/msm/registers/adreno/adreno_pm4.xml | 39 +- > >>> include/uapi/drm/msm_drm.h | 5 +- > >>> 20 files changed, 1117 insertions(+), 66 deletions(-) > >>> --- > >>> base-commit: 7c626ce4bae1ac14f60076d00eafe71af30450ba > >>> change-id: 20240815-preemption-a750-t-fcee9a844b39 > >>> > >>> Best regards, > >> > >> I've been running vulkan-cts (1.3.7.3-0-gd71a36db16d98313c431829432a136dbda692a08 from Yocto) > >> on SM8650-QRD, SM8550-QRD & SM8450-HDK boards with enable_preemption in default value > >> and forced to 1, and I've seen no regression so far > >> > >> On SM8550, I've seen a few: > >> platform 3d6a000.gmu: [drm:a6xx_hfi_send_msg.constprop.0 [msm]] *ERROR* Message HFI_H2F_MSG_GX_BW_PERF_VOTE id 2743 timed out waiting for response > >> platform 3d6a000.gmu: [drm:a6xx_hfi_send_msg.constprop.0 [msm]] *ERROR* Unexpected message id 2743 on the response queue > >> but it's unrelated to preempt > >> > >> and on SM8450: > >> platform 3d6a000.gmu: [drm:a6xx_gmu_set_oob [msm]] *ERROR* Timeout waiting for GMU OOB set GPU_SET: 0x0 > >> msm_dpu ae01000.display-controller: [drm:hangcheck_handler [msm]] *ERROR* 7.3.0.1: hangcheck detected gpu lockup rb 0! > >> msm_dpu ae01000.display-controller: [drm:hangcheck_handler [msm]] *ERROR* 7.3.0.1: completed fence: 331235 > >> msm_dpu ae01000.display-controller: [drm:hangcheck_handler [msm]] *ERROR* 7.3.0.1: submitted fence: 331236 > >> adreno 3d00000.gpu: [drm:a6xx_irq [msm]] *ERROR* gpu fault ring 0 fence 50de4 status 00800005 rb 0000/0699 ib1 0000000000000000/0000 ib2 0000000000000000/0000 > >> msm_dpu ae01000.display-controller: [drm:recover_worker [msm]] *ERROR* 7.3.0.1: hangcheck recover! > >> msm_dpu ae01000.display-controller: [drm:recover_worker [msm]] *ERROR* 7.3.0.1: offending task: deqp-vk (/usr/lib/vulkan-cts/deqp-vk) > >> msm_dpu ae01000.display-controller: [drm:recover_worker [msm]] *ERROR* 7.3.0.1: hangcheck recover! > >> leading to a VK_ERROR_DEVICE_LOST, but again unrelated to preempt support. > >> > >> So you can also add: > >> Tested-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx> # on SM8550-QRD > >> Tested-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx> # on SM8450-HDK > >> > > > > Niel, > > > > On my x1e device, all submissions were somehow going into only a single > > ring, even the compositor's. Not sure why. So effectively preemption was > > not really exercised. I had to force one of the two benchmark I ran > > using the "highprio" mesa debug flag force submittions to ring 0. > > I think that is because GL applications (so most compositors) run > through zink which does not forward GL preemption to vulkan so yeah, for > GL applications the only way of getting preemption is the debug flag. I guess if it is mesa 24.2.x or newer it would be using the gallium driver. Which I guess would need xAMBLE stuff wired up. Outside of fd6_emit_restore() and fd6_gmem.cc there isn't really any state emit in IB1, so I guess it probably wouldn't be too hard to get preemption support wired up. BR, -R > Unfortunately this is not easy to fix in Zink because it creates one > VkDevice at screen creation and uses it for all GL contexts. Since GL > priority is provided per context and at context creation time Zink has > no way of handling this. > > Once TU will support more than one queue it will be possible for Zink to > create one queue per priority then pick one at context creation time. > Doing so would require a new vulkan extension for per queue global > priority. I had started working on this some time ago > https://gitlab.freedesktop.org/antonino/mesa/-/tree/priority_ext?ref_type=heads > but this solution will only be viable once TU can expose more than one > queue. > > > > > If possible it is a good idea to check the new preemption traces to > > ensure preemption kicks in. > > > > -Akhil > > > >> Thanks, > >> Neil > > > Best regards, > -- > Antonino Maniscalco <antomani103@xxxxxxxxx>
