On Tue, Nov 17, 2020 at 9:07 PM Andrey Grodzovsky Andrey.Grodzovsky@amd.com wrote:
On 11/17/20 2:49 PM, Daniel Vetter wrote:
On Tue, Nov 17, 2020 at 02:18:49PM -0500, Andrey Grodzovsky wrote:
On 11/17/20 1:52 PM, Daniel Vetter wrote:
On Tue, Nov 17, 2020 at 01:38:14PM -0500, Andrey Grodzovsky wrote:
On 6/22/20 5:53 AM, Daniel Vetter wrote:
On Sun, Jun 21, 2020 at 02:03:08AM -0400, Andrey Grodzovsky wrote: > No point to try recovery if device is gone, just messes up things. > > Signed-off-by: Andrey Grodzovsky andrey.grodzovsky@amd.com > --- > drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 16 ++++++++++++++++ > drivers/gpu/drm/amd/amdgpu/amdgpu_job.c | 8 ++++++++ > 2 files changed, 24 insertions(+) > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c > index 6932d75..5d6d3d9 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c > @@ -1129,12 +1129,28 @@ static int amdgpu_pci_probe(struct pci_dev *pdev, > return ret; > } > +static void amdgpu_cancel_all_tdr(struct amdgpu_device *adev) > +{ > + int i; > + > + for (i = 0; i < AMDGPU_MAX_RINGS; ++i) { > + struct amdgpu_ring *ring = adev->rings[i]; > + > + if (!ring || !ring->sched.thread) > + continue; > + > + cancel_delayed_work_sync(&ring->sched.work_tdr); > + } > +} I think this is a function that's supposed to be in drm/scheduler, not here. Might also just be your cleanup code being ordered wrongly, or your split in one of the earlier patches not done quite right. -Daniel
This function iterates across all the schedulers per amdgpu device and accesses amdgpu specific structures , drm/scheduler deals with single scheduler at most so looks to me like this is the right place for this function
I guess we could keep track of all schedulers somewhere in a list in struct drm_device and wrap this up. That was kinda the idea.
Minimally I think a tiny wrapper with docs for the cancel_delayed_work_sync(&sched->work_tdr); which explains what you must observe to make sure there's no race.
Will do
I'm not exactly sure there's no guarantee here we won't get a new tdr work launched right afterwards at least, so this looks a bit like a hack.
Note that for any TDR work happening post amdgpu_cancel_all_tdr amdgpu_job_timedout->drm_dev_is_unplugged will return true and so it will return early. To make it water proof tight against race i can switch from drm_dev_is_unplugged to drm_dev_enter/exit
Hm that's confusing. You do a work_cancel_sync, so that at least looks like "tdr work must not run after this point"
If you only rely on drm_dev_enter/exit check with the tdr work, then there's no need to cancel anything.
Agree, synchronize_srcu from drm_dev_unplug should play the role of 'flushing' any earlier (in progress) tdr work which is using drm_dev_enter/exit pair. Any later arising tdr will terminate early when drm_dev_enter returns false.
Nope, anything you put into the work itself cannot close this race. It's the schedule_work that matters here. Or I'm missing something ... I thought that the tdr work you're cancelling here is launched by drm/scheduler code, not by the amd callback? -Daniel
Will update.
Andrey
For race free cancel_work_sync you need:
- make sure whatever is calling schedule_work is guaranteed to no longer
call schedule_work. 2. call cancel_work_sync
Anything else is cargo-culted work cleanup:
a problem.
- without 2. means if a work got scheduled right before it'll still be
cancel_work_sync pointless.
- without 1. means a schedule_work right after makes you calling
So either both or nothing. -Daniel
Andrey
-Daniel
Andrey
> + > static void > amdgpu_pci_remove(struct pci_dev *pdev) > { > struct drm_device *dev = pci_get_drvdata(pdev); > + struct amdgpu_device *adev = dev->dev_private; > drm_dev_unplug(dev); > + amdgpu_cancel_all_tdr(adev); > ttm_bo_unmap_virtual_address_space(&adev->mman.bdev); > amdgpu_driver_unload_kms(dev); > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c > index 4720718..87ff0c0 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c > @@ -28,6 +28,8 @@ > #include "amdgpu.h" > #include "amdgpu_trace.h" > +#include <drm/drm_drv.h> > + > static void amdgpu_job_timedout(struct drm_sched_job *s_job) > { > struct amdgpu_ring *ring = to_amdgpu_ring(s_job->sched); > @@ -37,6 +39,12 @@ static void amdgpu_job_timedout(struct drm_sched_job *s_job) > memset(&ti, 0, sizeof(struct amdgpu_task_info)); > + if (drm_dev_is_unplugged(adev->ddev)) { > + DRM_INFO("ring %s timeout, but device unplugged, skipping.\n", > + s_job->sched->name); > + return; > + } > + > if (amdgpu_ring_soft_recovery(ring, job->vmid, s_job->s_fence->parent)) { > DRM_ERROR("ring %s timeout, but soft recovered\n", > s_job->sched->name); > -- > 2.7.4 >