On Mon, 2024-08-26 at 14:25 +0200, Christian König wrote:
> The current implementation of drm_sched_start uses a hardcoded
> -ECANCELED to dispose of a job when the parent/hw fence is NULL.
> This results in drm_sched_job_done being called with -ECANCELED for
> each job with a NULL parent in the pending list, making it difficult
> to distinguish between recovery methods, whether a queue reset or a
> full GPU reset was used.
>
> To improve this, we first try a soft recovery for timeout jobs and
> use the error code -ENODATA. If soft recovery fails, we proceed with
> a queue reset, where the error code remains -ENODATA for the job.
> Finally, for a full GPU reset, we use error codes -ECANCELED or
> -ETIME. This patch adds an error code parameter to drm_sched_start,
> allowing us to differentiate between queue reset and GPU reset
> failures. This enables user mode and test applications to validate
> the expected correctness of the requested operation. After a
> successful queue reset, the only way to continue normal operation is
> to call drm_sched_job_done with the specific error code -ENODATA.
>
> v1: Initial implementation by Jesse utilized
> amdgpu_device_lock_reset_domain
> and amdgpu_device_unlock_reset_domain to allow user mode to track
> the queue reset status and distinguish between queue reset and
> GPU reset.
> v2: Christian suggested using the error codes -ENODATA for queue
> reset
> and -ECANCELED or -ETIME for GPU reset, returned to
> amdgpu_cs_wait_ioctl.
> v3: To meet the requirements, we introduce a new function
> drm_sched_start_ex with an additional parameter to set
> dma_fence_set_error, allowing us to handle the specific error
> codes appropriately and dispose of bad jobs with the selected
> error code depending on whether it was a queue reset or GPU
> reset.
> v4: Alex suggested using a new name,
> drm_sched_start_with_recovery_error,
> which more accurately describes the function's purpose.
> Additionally, it was recommended to add documentation details
> about the new method.
> v5: Fixed declaration of new function
> drm_sched_start_with_recovery_error.(Alex)
> v6 (chk): rebase on upstream changes, cleanup the commit message,
> drop the new function again and update all callers,
> apply the errno also to scheduler fences with hw fences
>
> Signed-off-by: Jesse Zhang <Jesse.Zhang@xxxxxxx>
> Signed-off-by: Vitaly Prosyak <vitaly.prosyak@xxxxxxx>
> Signed-off-by: Christian König <christian.koenig@xxxxxxx>
> Cc: Alex Deucher <alexander.deucher@xxxxxxx>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c | 2 +-
> drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 4 ++--
> drivers/gpu/drm/etnaviv/etnaviv_sched.c | 2 +-
> drivers/gpu/drm/imagination/pvr_queue.c | 4 ++--
> drivers/gpu/drm/lima/lima_sched.c | 2 +-
> drivers/gpu/drm/nouveau/nouveau_sched.c | 2 +-
> drivers/gpu/drm/panfrost/panfrost_job.c | 2 +-
> drivers/gpu/drm/panthor/panthor_mmu.c | 2 +-
> drivers/gpu/drm/scheduler/sched_main.c | 7 ++++---
> drivers/gpu/drm/v3d/v3d_sched.c | 2 +-
> include/drm/gpu_scheduler.h | 2 +-
> 11 files changed, 16 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c
> index 2320df51c914..18135d8235f9 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c
> @@ -300,7 +300,7 @@ static int
> suspend_resume_compute_scheduler(struct amdgpu_device *adev, bool sus
> if (r)
> goto out;
> } else {
> - drm_sched_start(&ring->sched);
> + drm_sched_start(&ring->sched, 0);
> }
> }
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index 1cd7d355689c..5891312e44ea 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -5879,7 +5879,7 @@ int amdgpu_device_gpu_recover(struct
> amdgpu_device *adev,
> if (!amdgpu_ring_sched_ready(ring))
> continue;
>
> - drm_sched_start(&ring->sched);
> + drm_sched_start(&ring->sched, 0);
> }
>
> if
> (!drm_drv_uses_atomic_modeset(adev_to_drm(tmp_adev)) &&
> !job_signaled)
> @@ -6374,7 +6374,7 @@ void amdgpu_pci_resume(struct pci_dev *pdev)
> if (!amdgpu_ring_sched_ready(ring))
> continue;
>
> - drm_sched_start(&ring->sched);
> + drm_sched_start(&ring->sched, 0);
> }
>
> amdgpu_device_unset_mp1_state(adev);
> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_sched.c
> b/drivers/gpu/drm/etnaviv/etnaviv_sched.c
> index ab9ca4824b62..23ced5896c7c 100644
> --- a/drivers/gpu/drm/etnaviv/etnaviv_sched.c
> +++ b/drivers/gpu/drm/etnaviv/etnaviv_sched.c
> @@ -72,7 +72,7 @@ static enum drm_gpu_sched_stat
> etnaviv_sched_timedout_job(struct drm_sched_job
>
> drm_sched_resubmit_jobs(&gpu->sched);
>
> - drm_sched_start(&gpu->sched);
> + drm_sched_start(&gpu->sched, 0);
> return DRM_GPU_SCHED_STAT_NOMINAL;
>
> out_no_timeout:
> diff --git a/drivers/gpu/drm/imagination/pvr_queue.c
> b/drivers/gpu/drm/imagination/pvr_queue.c
> index 20cb46012082..c4f08432882b 100644
> --- a/drivers/gpu/drm/imagination/pvr_queue.c
> +++ b/drivers/gpu/drm/imagination/pvr_queue.c
> @@ -782,7 +782,7 @@ static void pvr_queue_start(struct pvr_queue
> *queue)
> }
> }
>
> - drm_sched_start(&queue->scheduler);
> + drm_sched_start(&queue->scheduler, 0);
> }
>
> /**
> @@ -842,7 +842,7 @@ pvr_queue_timedout_job(struct drm_sched_job
> *s_job)
> }
> mutex_unlock(&pvr_dev->queues.lock);
>
> - drm_sched_start(sched);
> + drm_sched_start(sched, 0);
>
> return DRM_GPU_SCHED_STAT_NOMINAL;
> }
> diff --git a/drivers/gpu/drm/lima/lima_sched.c
> b/drivers/gpu/drm/lima/lima_sched.c
> index 1a944edb6ddc..b40c90e97d7e 100644
> --- a/drivers/gpu/drm/lima/lima_sched.c
> +++ b/drivers/gpu/drm/lima/lima_sched.c
> @@ -463,7 +463,7 @@ static enum drm_gpu_sched_stat
> lima_sched_timedout_job(struct drm_sched_job *job
> lima_pm_idle(ldev);
>
> drm_sched_resubmit_jobs(&pipe->base);
> - drm_sched_start(&pipe->base);
> + drm_sched_start(&pipe->base, 0);
>
> return DRM_GPU_SCHED_STAT_NOMINAL;
> }
> diff --git a/drivers/gpu/drm/nouveau/nouveau_sched.c
> b/drivers/gpu/drm/nouveau/nouveau_sched.c
> index eb6c3f9a01f5..4412f2711fb5 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_sched.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_sched.c
> @@ -379,7 +379,7 @@ nouveau_sched_timedout_job(struct drm_sched_job
> *sched_job)
> else
> NV_PRINTK(warn, job->cli, "Generic job timeout.\n");
>
> - drm_sched_start(sched);
> + drm_sched_start(sched, 0);
>
> return stat;
> }
> diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c
> b/drivers/gpu/drm/panfrost/panfrost_job.c
> index df49d37d0e7e..d140800606bf 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_job.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_job.c
> @@ -727,7 +727,7 @@ panfrost_reset(struct panfrost_device *pfdev,
>
> /* Restart the schedulers */
> for (i = 0; i < NUM_JOB_SLOTS; i++)
> - drm_sched_start(&pfdev->js->queue[i].sched);
> + drm_sched_start(&pfdev->js->queue[i].sched, 0);
>
> /* Re-enable job interrupts now that everything has been
> restarted. */
> job_write(pfdev, JOB_INT_MASK,
> diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c
> b/drivers/gpu/drm/panthor/panthor_mmu.c
> index d47972806d50..e630cdf47f99 100644
> --- a/drivers/gpu/drm/panthor/panthor_mmu.c
> +++ b/drivers/gpu/drm/panthor/panthor_mmu.c
> @@ -827,7 +827,7 @@ static void panthor_vm_stop(struct panthor_vm
> *vm)
>
> static void panthor_vm_start(struct panthor_vm *vm)
> {
> - drm_sched_start(&vm->sched);
> + drm_sched_start(&vm->sched, 0);
> }
>
> /**
> diff --git a/drivers/gpu/drm/scheduler/sched_main.c
> b/drivers/gpu/drm/scheduler/sched_main.c
> index ab53ab486fe6..f093616fe53c 100644
> --- a/drivers/gpu/drm/scheduler/sched_main.c
> +++ b/drivers/gpu/drm/scheduler/sched_main.c
> @@ -674,9 +674,10 @@ EXPORT_SYMBOL(drm_sched_stop);
> * drm_sched_start - recover jobs after a reset
> *
> * @sched: scheduler instance
> + * @errno: error to set on the pending fences
> *
> */
> -void drm_sched_start(struct drm_gpu_scheduler *sched)
> +void drm_sched_start(struct drm_gpu_scheduler *sched, int errno)
> {
> struct drm_sched_job *s_job, *tmp;
>
> @@ -691,13 +692,13 @@ void drm_sched_start(struct drm_gpu_scheduler
> *sched)
> atomic_add(s_job->credits, &sched->credit_count);
>
> if (!fence) {
> - drm_sched_job_done(s_job, -ECANCELED);
> + drm_sched_job_done(s_job, errno ?: -
> ECANCELED);
> continue;
> }
>
> if (dma_fence_add_callback(fence, &s_job->cb,
> drm_sched_job_done_cb))
> - drm_sched_job_done(s_job, fence->error);
> + drm_sched_job_done(s_job, fence->error ?:
> errno);
> }
>
> drm_sched_start_timeout_unlocked(sched);
> diff --git a/drivers/gpu/drm/v3d/v3d_sched.c
> b/drivers/gpu/drm/v3d/v3d_sched.c
> index fd29a00b233c..b6a89171824b 100644
> --- a/drivers/gpu/drm/v3d/v3d_sched.c
> +++ b/drivers/gpu/drm/v3d/v3d_sched.c
> @@ -663,7 +663,7 @@ v3d_gpu_reset_for_timeout(struct v3d_dev *v3d,
> struct drm_sched_job *sched_job)
>
> /* Unblock schedulers and restart their jobs. */
> for (q = 0; q < V3D_MAX_QUEUES; q++) {
> - drm_sched_start(&v3d->queue[q].sched);
> + drm_sched_start(&v3d->queue[q].sched, 0);
> }
>
> mutex_unlock(&v3d->reset_lock);
> diff --git a/include/drm/gpu_scheduler.h
> b/include/drm/gpu_scheduler.h
> index fe8edb917360..a8d19b10f9b8 100644
> --- a/include/drm/gpu_scheduler.h
> +++ b/include/drm/gpu_scheduler.h
> @@ -579,7 +579,7 @@ bool drm_sched_wqueue_ready(struct
> drm_gpu_scheduler *sched);
> void drm_sched_wqueue_stop(struct drm_gpu_scheduler *sched);
> void drm_sched_wqueue_start(struct drm_gpu_scheduler *sched);
> void drm_sched_stop(struct drm_gpu_scheduler *sched, struct
> drm_sched_job *bad);
> -void drm_sched_start(struct drm_gpu_scheduler *sched);
> +void drm_sched_start(struct drm_gpu_scheduler *sched, int errno);
I personally only recently started using the scheduler and many things
were quite confusing.
In particular, I thought it's not good to call this function
drm_sched_start(), because that implies to new users / programmers that
this function is supposed to start the scheduler.
Accordingly, drm_sched_stop() sounds as if it's intended to be used on
scheduler teardown. "Alright, I'll stop the scheduler with
drm_sched_stop(), then can safely call drm_sched_entity_destroy() and
then tear it down completely through drm_sched_fini()".
Now the comments make it obvious that those start and stop functions
are more intended for error recovery.
So my stance is that start should be called, e.g., drm_sched_restart()
or perhaps drm_sched_recover_start().
So since you're already touching all the lines where the function is
used, this might be a good opportunity to improve the name, too.
If that's deemed desirable.
P.
> void drm_sched_resubmit_jobs(struct drm_gpu_scheduler *sched);
> void drm_sched_increase_karma(struct drm_sched_job *bad);
> void drm_sched_reset_karma(struct drm_sched_job *bad);
