[PATCH] drm/gpu-sched: fix force APP kill hang(v3)

Deng, Emily Emily.Deng at amd.com
Fri Apr 13 06:18:35 UTC 2018


Hi Monk,
    Another consideration, it will be better to put amdgpu_ctx_mgr_fini() beneath amdgpu_vm_fini, in 
this case, it will first set all ctx and vm entity rq to null, then set all the not scheduled job's fence to signal.

Best Wishes,
Emily Deng

> -----Original Message-----
> From: amd-gfx [mailto:amd-gfx-bounces at lists.freedesktop.org] On Behalf
> Of Deng, Emily
> Sent: Friday, April 13, 2018 2:08 PM
> To: Liu, Monk <Monk.Liu at amd.com>; Christian K├Ânig
> <ckoenig.leichtzumerken at gmail.com>
> Cc: amd-gfx at lists.freedesktop.org
> Subject: RE: [PATCH] drm/gpu-sched: fix force APP kill hang(v3)
> 
> Hi Monk,
>      Thanks your review, I will refine the code as your suggestion 1),2),3), 4),5).
>      About 6): I think it is no relation to put the amdgpu_ctx_mgr_fini before or
> after amdgpu_vm_fini.
> 
> Hi Christian,
>      Do you have any thoughts about 6)?
> 
> Best Wishes,
> Emily Deng
> 
> > -----Original Message-----
> > From: amd-gfx [mailto:amd-gfx-bounces at lists.freedesktop.org] On Behalf
> > Of monk
> > Sent: Friday, April 13, 2018 1:01 PM
> > To: Deng, Emily <Emily.Deng at amd.com>; amd-gfx at lists.freedesktop.org
> > Subject: Re: [PATCH] drm/gpu-sched: fix force APP kill hang(v3)
> >
> > Hi Christian & Emily
> >
> > This v3 version looks pretty good to me, but still some parts need to
> > improve:
> >
> > e.g.
> >
> > 1)entity->finished doesn't presenting what it really means, better
> > rename it to entity->last_scheduled.
> >
> > 2)drm_sched_entity_fini_job_cb() better renamed to
> > drm_sched_entity_kill_jobs_cb()
> >
> > 3) no need to pass "entity->finished" (line275 of gpu_schedulers.c) to
> > drm_sched_entity_fini_job_cb() if -ENOENT returned after
> > dma_fence_add_callback since this parm is not needed at all in this
> > callback routine
> >
> > 4)better change type of entity->fini_status to "int" instead of
> > "uint32_t" ... it should be aligned with the return type of
> > wait_event_killable()
> >
> > 5)
> >
> > +		if (entity->finished) {
> > +			dma_fence_put(entity->finished);
> > +			entity->finished = NULL;
> >   		}
> >
> > no need to check entity->finished because dma_fence_put() will do it
> inside...
> >
> >
> >
> > and the same here in job_recovery:
> >
> > +
> > +		if (s_job->entity->finished)
> > +			dma_fence_put(s_job->entity->finished);
> >
> > and the same here in sched_main:
> >
> > +		if (entity->finished)
> > +			dma_fence_put(entity->finished);
> >
> >
> > 6) why put amdgpu_ctx_mgr_fini() beneath amdgpu_vm_fini() ? any reason
> > for that ?
> >
> >
> > thanks
> >
> > /Monk
> >
> >
> >
> >
> >
> >
> > On 04/13/2018 10:06 AM, Deng, Emily wrote:
> > > Ping....
> > >
> > > Best Wishes,
> > > Emily Deng
> > >
> > >
> > >
> > >
> > >> -----Original Message-----
> > >> From: Emily Deng [mailto:Emily.Deng at amd.com]
> > >> Sent: Thursday, April 12, 2018 6:22 PM
> > >> To: amd-gfx at lists.freedesktop.org
> > >> Cc: Deng, Emily <Emily.Deng at amd.com>; Liu, Monk
> > <Monk.Liu at amd.com>
> > >> Subject: [PATCH] drm/gpu-sched: fix force APP kill hang(v3)
> > >>
> > >> issue:
> > >> there are VMC page fault occurred if force APP kill during 3dmark
> > >> test, the cause is in entity_fini we manually signal all those jobs
> > >> in entity's queue which confuse the sync/dep
> > >> mechanism:
> > >>
> > >> 1)page fault occurred in sdma's clear job which operate on shadow
> > >> buffer, and shadow buffer's Gart table is cleaned by ttm_bo_release
> > >> since the fence in its reservation was fake signaled by
> > >> entity_fini() under the case of SIGKILL received.
> > >>
> > >> 2)page fault occurred in gfx' job because during the lifetime of
> > >> gfx job we manually fake signal all jobs from its entity in
> > >> entity_fini(), thus the unmapping/clear PTE job depend on those
> > >> result fence is satisfied and sdma start clearing the PTE and lead
> > >> to GFX
> > page fault.
> > >>
> > >> fix:
> > >> 1)should at least wait all jobs already scheduled complete in
> > >> entity_fini() if SIGKILL is the case.
> > >>
> > >> 2)if a fence signaled and try to clear some entity's dependency,
> > >> should set this entity guilty to prevent its job really run since
> > >> the dependency is fake signaled.
> > >>
> > >> v2:
> > >> splitting drm_sched_entity_fini() into two functions:
> > >> 1)The first one is does the waiting, removes the entity from the
> > >> runqueue and returns an error when the process was killed.
> > >> 2)The second one then goes over the entity, install it as
> > >> completion signal for the remaining jobs and signals all jobs with an
> error code.
> > >>
> > >> v3:
> > >> 1)Replace the fini1 and fini2 with better name 2)Call the first
> > >> part before the VM teardown in
> > >> amdgpu_driver_postclose_kms() and the second part after the VM
> > >> teardown 3)Keep the original function drm_sched_entity_fini to
> > >> refine the
> > code.
> > >>
> > >> Signed-off-by: Monk Liu <Monk.Liu at amd.com>
> > >> Signed-off-by: Emily Deng <Emily.Deng at amd.com>
> > >> ---
> > >>   drivers/gpu/drm/amd/amdgpu/amdgpu.h       |  2 +
> > >>   drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c   | 64
> > >> ++++++++++++++++++++++----
> > >>   drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c   |  5 ++-
> > >>   drivers/gpu/drm/scheduler/gpu_scheduler.c | 74
> > >> ++++++++++++++++++++++++++-----
> > >>   include/drm/gpu_scheduler.h               |  7 +++
> > >>   5 files changed, 131 insertions(+), 21 deletions(-)
> > >>
> > >> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> > >> b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> > >> index 2babfad..200db73 100644
> > >> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> > >> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> > >> @@ -681,6 +681,8 @@ int amdgpu_ctx_ioctl(struct drm_device *dev,
> > void
> > >> *data,  int amdgpu_ctx_wait_prev_fence(struct amdgpu_ctx *ctx,
> > >> unsigned ring_id);
> > >>
> > >>   void amdgpu_ctx_mgr_init(struct amdgpu_ctx_mgr *mgr);
> > >> +void amdgpu_ctx_mgr_entity_cleanup(struct amdgpu_ctx_mgr *mgr);
> > void
> > >> +amdgpu_ctx_mgr_entity_fini(struct amdgpu_ctx_mgr *mgr);
> > >>   void amdgpu_ctx_mgr_fini(struct amdgpu_ctx_mgr *mgr);
> > >>
> > >>
> > >> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
> > >> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
> > >> index 09d35051..659add4 100644
> > >> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
> > >> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
> > >> @@ -111,8 +111,9 @@ static int amdgpu_ctx_init(struct
> amdgpu_device
> > >> *adev,
> > >>   	return r;
> > >>   }
> > >>
> > >> -static void amdgpu_ctx_fini(struct amdgpu_ctx *ctx)
> > >> +static void amdgpu_ctx_fini(struct kref *ref)
> > >>   {
> > >> +	struct amdgpu_ctx *ctx = container_of(ref, struct amdgpu_ctx,
> > >> +refcount);
> > >>   	struct amdgpu_device *adev = ctx->adev;
> > >>   	unsigned i, j;
> > >>
> > >> @@ -125,13 +126,11 @@ static void amdgpu_ctx_fini(struct
> amdgpu_ctx
> > >> *ctx)
> > >>   	kfree(ctx->fences);
> > >>   	ctx->fences = NULL;
> > >>
> > >> -	for (i = 0; i < adev->num_rings; i++)
> > >> -		drm_sched_entity_fini(&adev->rings[i]->sched,
> > >> -				      &ctx->rings[i].entity);
> > >> -
> > >>   	amdgpu_queue_mgr_fini(adev, &ctx->queue_mgr);
> > >>
> > >>   	mutex_destroy(&ctx->lock);
> > >> +
> > >> +	kfree(ctx);
> > >>   }
> > >>
> > >>   static int amdgpu_ctx_alloc(struct amdgpu_device *adev, @@
> > >> -170,12
> > >> +169,15 @@ static int amdgpu_ctx_alloc(struct amdgpu_device *adev,
> > >> static void amdgpu_ctx_do_release(struct kref *ref)  {
> > >>   	struct amdgpu_ctx *ctx;
> > >> +	u32 i;
> > >>
> > >>   	ctx = container_of(ref, struct amdgpu_ctx, refcount);
> > >>
> > >> -	amdgpu_ctx_fini(ctx);
> > >> +	for (i = 0; i < ctx->adev->num_rings; i++)
> > >> +		drm_sched_entity_fini(&ctx->adev->rings[i]->sched,
> > >> +							&ctx->rings[i].entity);
> > >>
> > >> -	kfree(ctx);
> > >> +	amdgpu_ctx_fini(ref);
> > >>   }
> > >>
> > >>   static int amdgpu_ctx_free(struct amdgpu_fpriv *fpriv, uint32_t
> > >> id) @@ -
> > >> 435,16 +437,62 @@ void amdgpu_ctx_mgr_init(struct amdgpu_ctx_mgr
> > >> *mgr)
> > >>   	idr_init(&mgr->ctx_handles);
> > >>   }
> > >>
> > >> +void amdgpu_ctx_mgr_entity_fini(struct amdgpu_ctx_mgr *mgr) {
> > >> +	struct amdgpu_ctx *ctx;
> > >> +	struct idr *idp;
> > >> +	uint32_t id, i;
> > >> +
> > >> +	idp = &mgr->ctx_handles;
> > >> +
> > >> +	idr_for_each_entry(idp, ctx, id) {
> > >> +
> > >> +		if (!ctx->adev)
> > >> +			return;
> > >> +
> > >> +		for (i = 0; i < ctx->adev->num_rings; i++)
> > >> +			if (kref_read(&ctx->refcount) == 1)
> > >> +				drm_sched_entity_do_release(&ctx->adev-
> > >>> rings[i]->sched,
> > >> +						  &ctx->rings[i].entity);
> > >> +			else
> > >> +				DRM_ERROR("ctx %p is still alive\n", ctx);
> > >> +	}
> > >> +}
> > >> +
> > >> +void amdgpu_ctx_mgr_entity_cleanup(struct amdgpu_ctx_mgr *mgr) {
> > >> +	struct amdgpu_ctx *ctx;
> > >> +	struct idr *idp;
> > >> +	uint32_t id, i;
> > >> +
> > >> +	idp = &mgr->ctx_handles;
> > >> +
> > >> +	idr_for_each_entry(idp, ctx, id) {
> > >> +
> > >> +		if (!ctx->adev)
> > >> +			return;
> > >> +
> > >> +		for (i = 0; i < ctx->adev->num_rings; i++)
> > >> +			if (kref_read(&ctx->refcount) == 1)
> > >> +				drm_sched_entity_cleanup(&ctx->adev-
> > >>> rings[i]->sched,
> > >> +					&ctx->rings[i].entity);
> > >> +			else
> > >> +				DRM_ERROR("ctx %p is still alive\n", ctx);
> > >> +	}
> > >> +}
> > >> +
> > >>   void amdgpu_ctx_mgr_fini(struct amdgpu_ctx_mgr *mgr)  {
> > >>   	struct amdgpu_ctx *ctx;
> > >>   	struct idr *idp;
> > >>   	uint32_t id;
> > >>
> > >> +	amdgpu_ctx_mgr_entity_cleanup(mgr);
> > >> +
> > >>   	idp = &mgr->ctx_handles;
> > >>
> > >>   	idr_for_each_entry(idp, ctx, id) {
> > >> -		if (kref_put(&ctx->refcount, amdgpu_ctx_do_release) != 1)
> > >> +		if (kref_put(&ctx->refcount, amdgpu_ctx_fini) != 1)
> > >>   			DRM_ERROR("ctx %p is still alive\n", ctx);
> > >>   	}
> > >>
> > >> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
> > >> b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
> > >> index 487d39e..6cbb427 100644
> > >> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
> > >> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
> > >> @@ -913,8 +913,7 @@ void amdgpu_driver_postclose_kms(struct
> > >> drm_device *dev,
> > >>   		return;
> > >>
> > >>   	pm_runtime_get_sync(dev->dev);
> > >> -
> > >> -	amdgpu_ctx_mgr_fini(&fpriv->ctx_mgr);
> > >> +	amdgpu_ctx_mgr_entity_fini(&fpriv->ctx_mgr);
> > >>
> > >>   	if (adev->asic_type != CHIP_RAVEN) {
> > >>   		amdgpu_uvd_free_handles(adev, file_priv); @@ -935,6
> > >> +934,8 @@ void amdgpu_driver_postclose_kms(struct drm_device *dev,
> > >>   	pd = amdgpu_bo_ref(fpriv->vm.root.base.bo);
> > >>
> > >>   	amdgpu_vm_fini(adev, &fpriv->vm);
> > >> +	amdgpu_ctx_mgr_fini(&fpriv->ctx_mgr);
> > >> +
> > >>   	if (pasid)
> > >>   		amdgpu_pasid_free_delayed(pd->tbo.resv, pasid);
> > >>   	amdgpu_bo_unref(&pd);
> > >> diff --git a/drivers/gpu/drm/scheduler/gpu_scheduler.c
> > >> b/drivers/gpu/drm/scheduler/gpu_scheduler.c
> > >> index 310275e..9062d44 100644
> > >> --- a/drivers/gpu/drm/scheduler/gpu_scheduler.c
> > >> +++ b/drivers/gpu/drm/scheduler/gpu_scheduler.c
> > >> @@ -136,6 +136,8 @@ int drm_sched_entity_init(struct
> > >> drm_gpu_scheduler *sched,
> > >>   	entity->rq = rq;
> > >>   	entity->sched = sched;
> > >>   	entity->guilty = guilty;
> > >> +	entity->fini_status = 0;
> > >> +	entity->finished = NULL;
> > >>
> > >>   	spin_lock_init(&entity->rq_lock);
> > >>   	spin_lock_init(&entity->queue_lock);
> > >> @@ -197,19 +199,30 @@ static bool drm_sched_entity_is_ready(struct
> > >> drm_sched_entity *entity)
> > >>   	return true;
> > >>   }
> > >>
> > >> +static void drm_sched_entity_fini_job_cb(struct dma_fence *f,
> > >> +				    struct dma_fence_cb *cb)
> > >> +{
> > >> +	struct drm_sched_job *job = container_of(cb, struct drm_sched_job,
> > >> +						 finish_cb);
> > >> +	drm_sched_fence_finished(job->s_fence);
> > >> +	WARN_ON(job->s_fence->parent);
> > >> +	dma_fence_put(&job->s_fence->finished);
> > >> +	job->sched->ops->free_job(job);
> > >> +}
> > >> +
> > >> +
> > >>   /**
> > >>    * Destroy a context entity
> > >>    *
> > >>    * @sched       Pointer to scheduler instance
> > >>    * @entity	The pointer to a valid scheduler entity
> > >>    *
> > >> - * Cleanup and free the allocated resources.
> > >> + * Splitting drm_sched_entity_fini() into two functions, The first
> > >> + one is does the waiting,
> > >> + * removes the entity from the runqueue and returns an error when
> > >> + the
> > >> process was killed.
> > >>    */
> > >> -void drm_sched_entity_fini(struct drm_gpu_scheduler *sched,
> > >> +void drm_sched_entity_do_release(struct drm_gpu_scheduler *sched,
> > >>   			   struct drm_sched_entity *entity)
> > >>   {
> > >> -	int r;
> > >> -
> > >>   	if (!drm_sched_entity_is_initialized(sched, entity))
> > >>   		return;
> > >>   	/**
> > >> @@ -217,13 +230,28 @@ void drm_sched_entity_fini(struct
> > >> drm_gpu_scheduler *sched,
> > >>   	 * queued IBs or discard them on SIGKILL
> > >>   	*/
> > >>   	if ((current->flags & PF_SIGNALED) && current->exit_code == SIGKILL)
> > >> -		r = -ERESTARTSYS;
> > >> +		entity->fini_status = -ERESTARTSYS;
> > >>   	else
> > >> -		r = wait_event_killable(sched->job_scheduled,
> > >> +		entity->fini_status = wait_event_killable(sched-
> > >>> job_scheduled,
> > >>   					drm_sched_entity_is_idle(entity));
> > >>   	drm_sched_entity_set_rq(entity, NULL);
> > >> -	if (r) {
> > >> +}
> > >> +EXPORT_SYMBOL(drm_sched_entity_do_release);
> > >> +
> > >> +/**
> > >> + * Destroy a context entity
> > >> + *
> > >> + * @sched       Pointer to scheduler instance
> > >> + * @entity	The pointer to a valid scheduler entity
> > >> + *
> > >> + * The second one then goes over the entity and signals all jobs
> > >> +with an
> > >> error code.
> > >> + */
> > >> +void drm_sched_entity_cleanup(struct drm_gpu_scheduler *sched,
> > >> +			   struct drm_sched_entity *entity) {
> > >> +	if (entity->fini_status) {
> > >>   		struct drm_sched_job *job;
> > >> +		int r;
> > >>
> > >>   		/* Park the kernel for a moment to make sure it isn't
> > processing
> > >>   		 * our enity.
> > >> @@ -241,13 +269,28 @@ void drm_sched_entity_fini(struct
> > >> drm_gpu_scheduler *sched,
> > >>   			struct drm_sched_fence *s_fence = job->s_fence;
> > >>   			drm_sched_fence_scheduled(s_fence);
> > >>   			dma_fence_set_error(&s_fence->finished, -ESRCH);
> > >> -			drm_sched_fence_finished(s_fence);
> > >> -			WARN_ON(s_fence->parent);
> > >> -			dma_fence_put(&s_fence->finished);
> > >> -			sched->ops->free_job(job);
> > >> +			r = dma_fence_add_callback(entity->finished, &job-
> > >>> finish_cb,
> > >> +
> > >> 	drm_sched_entity_fini_job_cb);
> > >> +			if (r == -ENOENT)
> > >> +				drm_sched_entity_fini_job_cb(entity-
> > >>> finished, &job->finish_cb);
> > >> +			else if (r)
> > >> +				DRM_ERROR("fence add callback failed
> > >> (%d)\n", r);
> > >> +		}
> > >> +
> > >> +		if (entity->finished) {
> > >> +			dma_fence_put(entity->finished);
> > >> +			entity->finished = NULL;
> > >>   		}
> > >>   	}
> > >>   }
> > >> +EXPORT_SYMBOL(drm_sched_entity_cleanup);
> > >> +
> > >> +void drm_sched_entity_fini(struct drm_gpu_scheduler *sched,
> > >> +				struct drm_sched_entity *entity) {
> > >> +	drm_sched_entity_do_release(sched, entity);
> > >> +	drm_sched_entity_cleanup(sched, entity); }
> > >>   EXPORT_SYMBOL(drm_sched_entity_fini);
> > >>
> > >>   static void drm_sched_entity_wakeup(struct dma_fence *f, struct
> > >> dma_fence_cb *cb) @@ -530,6 +573,11 @@ void
> > >> drm_sched_job_recovery(struct drm_gpu_scheduler *sched)
> > >>   		spin_unlock(&sched->job_list_lock);
> > >>   		fence = sched->ops->run_job(s_job);
> > >>   		atomic_inc(&sched->hw_rq_count);
> > >> +
> > >> +		if (s_job->entity->finished)
> > >> +			dma_fence_put(s_job->entity->finished);
> > >> +		s_job->entity->finished = dma_fence_get(&s_fence-
> > >>> finished);
> > >> +
> > >>   		if (fence) {
> > >>   			s_fence->parent = dma_fence_get(fence);
> > >>   			r = dma_fence_add_callback(fence, &s_fence->cb,
> > @@ -556,6 +604,7
> > >> @@ int drm_sched_job_init(struct drm_sched_job *job,
> > >>   		       void *owner)
> > >>   {
> > >>   	job->sched = sched;
> > >> +	job->entity = entity;
> > >>   	job->s_priority = entity->rq - sched->sched_rq;
> > >>   	job->s_fence = drm_sched_fence_create(entity, owner);
> > >>   	if (!job->s_fence)
> > >> @@ -668,6 +717,9 @@ static int drm_sched_main(void *param)
> > >>
> > >>   		fence = sched->ops->run_job(sched_job);
> > >>   		drm_sched_fence_scheduled(s_fence);
> > >> +		if (entity->finished)
> > >> +			dma_fence_put(entity->finished);
> > >> +		entity->finished = dma_fence_get(&s_fence->finished);
> > >>
> > >>   		if (fence) {
> > >>   			s_fence->parent = dma_fence_get(fence); diff --git
> > >> a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h index
> > >> c053a32..a0dd947 100644
> > >> --- a/include/drm/gpu_scheduler.h
> > >> +++ b/include/drm/gpu_scheduler.h
> > >> @@ -65,6 +65,8 @@ struct drm_sched_entity {
> > >>   	struct dma_fence		*dependency;
> > >>   	struct dma_fence_cb		cb;
> > >>   	atomic_t			*guilty; /* points to ctx's guilty */
> > >> +	uint32_t            fini_status;
> > >> +	struct dma_fence    *finished;
> > >>   };
> > >>
> > >>   /**
> > >> @@ -119,6 +121,7 @@ struct drm_sched_job {
> > >>   	uint64_t			id;
> > >>   	atomic_t			karma;
> > >>   	enum drm_sched_priority		s_priority;
> > >> +	struct drm_sched_entity  *entity;
> > >>   };
> > >>
> > >>   static inline bool drm_sched_invalidate_job(struct drm_sched_job
> > >> *s_job, @@ -186,6 +189,10 @@ int drm_sched_entity_init(struct
> > >> drm_gpu_scheduler *sched,
> > >>   			  struct drm_sched_entity *entity,
> > >>   			  struct drm_sched_rq *rq,
> > >>   			  uint32_t jobs, atomic_t *guilty);
> > >> +void drm_sched_entity_do_release(struct drm_gpu_scheduler *sched,
> > >> +			   struct drm_sched_entity *entity); void
> > >> +drm_sched_entity_cleanup(struct drm_gpu_scheduler *sched,
> > >> +			   struct drm_sched_entity *entity);
> > >>   void drm_sched_entity_fini(struct drm_gpu_scheduler *sched,
> > >>   			   struct drm_sched_entity *entity);  void
> > >> drm_sched_entity_push_job(struct drm_sched_job *sched_job,
> > >> --
> > >> 2.7.4
> >
> > _______________________________________________
> > amd-gfx mailing list
> > amd-gfx at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/amd-gfx
> _______________________________________________
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