On Fri, 2024-08-30 at 15:15 +0200, Christian König wrote:
> Am 28.08.24 um 11:30 schrieb Philipp Stanner:
> > 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.
>
> Yeah completely agree.
>
> We also had people incorrectly thinking that they should call
> drm_sched_stop/start on suspend/resume resulting in a system which
> didn't come up again after resume.
>
> How about we call it drm_sched_suspend_before_reset() and
> drm_sched_resume_after_reset()?
Yes, that sounds bullet-proof to me :)
One might also consider drm_sched_start()'s function summary "recover
jobs after a reset". Maybe have a sentence about what "recover" means
would help there, too.
Regards,
P.
>
> Thanks,
> Christian.
>
> >
> > 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);
>
