[PATCH 18/21] drm/amdgpu: add framework for HW specific priority settings v3

Christian König deathsimple at vodafone.de
Fri Mar 3 13:46:09 UTC 2017


Am 02.03.2017 um 22:44 schrieb Andres Rodriguez:
> Add an initial framework for changing the HW priorities of rings. The
> framework allows requesting priority changes for the lifetime of an
> amdgpu_job. After the job completes the priority will decay to the next
> lowest priority for which a request is still valid.
>
> A new ring function set_priority() can now be populated to take care of
> the HW specific programming sequence for priority changes.
>
> v2: set priority before emitting IB, and take a ref on amdgpu_job
> v3: use AMD_SCHED_PRIORITY_* instead of AMDGPU_CTX_PRIORITY_*
> v4: plug amdgpu_ring_restore_priority_cb into amdgpu_job_free_cb
>
> Signed-off-by: Andres Rodriguez <andresx7 at gmail.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu.h      |  3 +-
>   drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c   |  2 +-
>   drivers/gpu/drm/amd/amdgpu/amdgpu_job.c  | 14 +++++-
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c | 73 ++++++++++++++++++++++++++++++++
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h | 12 ++++++
>   5 files changed, 100 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> index bf15373..e7e92fd 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> @@ -636,21 +636,21 @@ struct amdgpu_flip_work {
>   struct amdgpu_ib {
>   	struct amdgpu_sa_bo		*sa_bo;
>   	uint32_t			length_dw;
>   	uint64_t			gpu_addr;
>   	uint32_t			*ptr;
>   	uint32_t			flags;
>   };
>   
>   extern const struct amd_sched_backend_ops amdgpu_sched_ops;
>   
> -int amdgpu_job_alloc(struct amdgpu_device *adev, unsigned num_ibs,
> +int amdgpu_job_alloc(struct amdgpu_device *adev, unsigned num_ibs, int priority,
>   		     struct amdgpu_job **job, struct amdgpu_vm *vm);
>   int amdgpu_job_alloc_with_ib(struct amdgpu_device *adev, unsigned size,
>   			     struct amdgpu_job **job);
>   
>   void amdgpu_job_free_resources(struct amdgpu_job *job);
>   void amdgpu_job_free(struct amdgpu_job *job);
>   int amdgpu_job_submit(struct amdgpu_job *job, struct amdgpu_ring *ring,
>   		      struct amd_sched_entity *entity, void *owner,
>   		      struct dma_fence **f);
>   
> @@ -981,20 +981,21 @@ struct amdgpu_cs_parser {
>   #define AMDGPU_VM_DOMAIN                    (1 << 3) /* bit set means in virtual memory context */
>   
>   struct amdgpu_job {
>   	struct amd_sched_job    base;
>   	struct amdgpu_device	*adev;
>   	struct amdgpu_vm	*vm;
>   	struct amdgpu_ring	*ring;
>   	struct amdgpu_sync	sync;
>   	struct amdgpu_ib	*ibs;
>   	struct dma_fence	*fence; /* the hw fence */
> +	int			priority;

Actually that is unnecessary (and thinking more about it the priority in 
the context is unnecessary as well).

(job->base.sched->sched_rq - job->base.s_entity->rq) should give you the 
scheduler priority of the job as well.

We can add an inline helper in the scheduler for that.

Additional to that please use enum amd_sched_priority instead of int for 
the priority all over the patch.

>   	uint32_t		preamble_status;
>   	uint32_t		num_ibs;
>   	void			*owner;
>   	uint64_t		fence_ctx; /* the fence_context this job uses */
>   	bool                    vm_needs_flush;
>   	unsigned		vm_id;
>   	uint64_t		vm_pd_addr;
>   	uint32_t		gds_base, gds_size;
>   	uint32_t		gws_base, gws_size;
>   	uint32_t		oa_base, oa_size;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> index 605d40e..19ce202 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> @@ -179,21 +179,21 @@ int amdgpu_cs_parser_init(struct amdgpu_cs_parser *p, void *data)
>   
>   		case AMDGPU_CHUNK_ID_DEPENDENCIES:
>   			break;
>   
>   		default:
>   			ret = -EINVAL;
>   			goto free_partial_kdata;
>   		}
>   	}
>   
> -	ret = amdgpu_job_alloc(p->adev, num_ibs, &p->job, vm);
> +	ret = amdgpu_job_alloc(p->adev, num_ibs, p->ctx->priority, &p->job, vm);
>   	if (ret)
>   		goto free_all_kdata;
>   
>   	if (p->uf_entry.robj)
>   		p->job->uf_addr = uf_offset;
>   	kfree(chunk_array);
>   	return 0;
>   
>   free_all_kdata:
>   	i = p->nchunks - 1;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
> index 86a1242..28f8a50 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
> @@ -32,50 +32,51 @@ static void amdgpu_job_timedout(struct amd_sched_job *s_job)
>   {
>   	struct amdgpu_job *job = container_of(s_job, struct amdgpu_job, base);
>   
>   	DRM_ERROR("ring %s timeout, last signaled seq=%u, last emitted seq=%u\n",
>   		  job->base.sched->name,
>   		  atomic_read(&job->ring->fence_drv.last_seq),
>   		  job->ring->fence_drv.sync_seq);
>   	amdgpu_gpu_reset(job->adev);
>   }
>   
> -int amdgpu_job_alloc(struct amdgpu_device *adev, unsigned num_ibs,
> +int amdgpu_job_alloc(struct amdgpu_device *adev, unsigned num_ibs, int priority,
>   		     struct amdgpu_job **job, struct amdgpu_vm *vm)
>   {
>   	size_t size = sizeof(struct amdgpu_job);
>   
>   	if (num_ibs == 0)
>   		return -EINVAL;
>   
>   	size += sizeof(struct amdgpu_ib) * num_ibs;
>   
>   	*job = kzalloc(size, GFP_KERNEL);
>   	if (!*job)
>   		return -ENOMEM;
>   
>   	(*job)->adev = adev;
>   	(*job)->vm = vm;
> +	(*job)->priority = priority;
>   	(*job)->ibs = (void *)&(*job)[1];
>   	(*job)->num_ibs = num_ibs;
>   
>   	amdgpu_sync_create(&(*job)->sync);
>   
>   	return 0;
>   }
>   
>   int amdgpu_job_alloc_with_ib(struct amdgpu_device *adev, unsigned size,
>   			     struct amdgpu_job **job)
>   {
>   	int r;
>   
> -	r = amdgpu_job_alloc(adev, 1, job, NULL);
> +	r = amdgpu_job_alloc(adev, 1, AMD_SCHED_PRIORITY_NORMAL, job, NULL);
>   	if (r)
>   		return r;
>   
>   	r = amdgpu_ib_get(adev, NULL, size, &(*job)->ibs[0]);
>   	if (r)
>   		kfree(*job);
>   
>   	return r;
>   }
>   
> @@ -88,20 +89,24 @@ void amdgpu_job_free_resources(struct amdgpu_job *job)
>   	f = job->base.s_fence ? &job->base.s_fence->finished : job->fence;
>   
>   	for (i = 0; i < job->num_ibs; ++i)
>   		amdgpu_ib_free(job->adev, &job->ibs[i], f);
>   }
>   
>   static void amdgpu_job_free_cb(struct amd_sched_job *s_job)
>   {
>   	struct amdgpu_job *job = container_of(s_job, struct amdgpu_job, base);
>   
> +	/* no need to restore if we are already at the lowest priority */
> +	if (job->priority < AMD_SCHED_PRIORITY_NORMAL)
> +		amdgpu_ring_restore_priority_cb(job);

Please put that check into amdgpu_ring_restore_priority_cb(). And by the 
way remove the _cb postfix from amdgpu_ring_restore_priority_cb().

> +
>   	dma_fence_put(job->fence);
>   	amdgpu_sync_free(&job->sync);
>   	kfree(job);
>   }
>   
>   void amdgpu_job_free(struct amdgpu_job *job)
>   {
>   	amdgpu_job_free_resources(job);
>   
>   	dma_fence_put(job->fence);
> @@ -162,28 +167,33 @@ static struct dma_fence *amdgpu_job_run(struct amd_sched_job *sched_job)
>   	int r;
>   
>   	if (!sched_job) {
>   		DRM_ERROR("job is null\n");
>   		return NULL;
>   	}
>   	job = to_amdgpu_job(sched_job);
>   
>   	BUG_ON(amdgpu_sync_peek_fence(&job->sync, NULL));
>   
> +	r = amdgpu_ring_elevate_priority(job->ring, job->priority, job);
> +	if (r)
> +		DRM_ERROR("Failed to set job priority (%d)\n", r);
> +
>   	trace_amdgpu_sched_run_job(job);
>   	r = amdgpu_ib_schedule(job->ring, job->num_ibs, job->ibs, job, &fence);
>   	if (r)
>   		DRM_ERROR("Error scheduling IBs (%d)\n", r);
>   
>   	/* if gpu reset, hw fence will be replaced here */
>   	dma_fence_put(job->fence);
>   	job->fence = dma_fence_get(fence);
> +
>   	amdgpu_job_free_resources(job);
>   	return fence;
>   }
>   
>   const struct amd_sched_backend_ops amdgpu_sched_ops = {
>   	.dependency = amdgpu_job_dependency,
>   	.run_job = amdgpu_job_run,
>   	.timedout_job = amdgpu_job_timedout,
>   	.free_job = amdgpu_job_free_cb
>   };
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> index 31c6274..fa6e72f2 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> @@ -193,20 +193,91 @@ void amdgpu_ring_commit(struct amdgpu_ring *ring)
>    */
>   void amdgpu_ring_undo(struct amdgpu_ring *ring)
>   {
>   	ring->wptr = ring->wptr_old;
>   
>   	if (ring->funcs->end_use)
>   		ring->funcs->end_use(ring);
>   }
>   
>   /**
> + * amdgpu_ring_restore_priority_cb - restore a ring's priority
> + *
> + * @job: job which completed execution
> + *
> + * If necessary, restore a ring's priority after a job finishes executing
> + */
> +void amdgpu_ring_restore_priority_cb(struct amdgpu_job *job)
> +{
> +	int i;
> +	struct amdgpu_ring *ring = job->ring;
> +
> +	spin_lock(&ring->priority_lock);
> +
> +	/* remove ourselves from the list if necessary */
> +	if (job == ring->last_job[job->priority])
> +		ring->last_job[job->priority] = NULL;
> +
> +	/* something higher prio is executing, no need to decay */
> +	if (ring->priority < job->priority)
> +		goto out_unlock;
> +
> +	/* decay priority to the next level with a job available */
> +	for (i = job->priority; i < AMD_SCHED_MAX_PRIORITY; i++) {
> +		if (i == AMD_SCHED_PRIORITY_NORMAL || ring->last_job[i]) {
> +			ring->priority = i;
> +			if (ring->funcs->set_priority)
> +				ring->funcs->set_priority(ring, i);
> +
> +			break;
> +		}
> +	}
> +
> +out_unlock:
> +	spin_unlock(&ring->priority_lock);
> +}

If you use an atomic to count the number of jobs for each priority 
running you would only need the spinlock for updating the priority.

Additional to that I would abort early if ring->funcs->set_priority 
isn't available (e.g. before doing anything else).

Regards,
Christian.

> +
> +/**
> + * amdgpu_ring_elevate_priority - change the ring's priority
> + *
> + * @ring: amdgpu_ring structure holding the information
> + * @priority: target priority
> + * @job: priority should remain elevated for the duration of this job
> + *
> + * Use HW specific mechanism's to elevate the ring's priority while @job
> + * is executing. Once @job finishes executing, the ring will reset back
> + * to normal priority.
> + * Returns 0 on success, error otherwise
> + */
> +int amdgpu_ring_elevate_priority(struct amdgpu_ring *ring, int priority,
> +				 struct amdgpu_job *job)
> +{
> +	if (priority < 0 || priority >= AMD_SCHED_MAX_PRIORITY)
> +		return -EINVAL;
> +
> +	spin_lock(&ring->priority_lock);
> +	ring->last_job[priority] = job;
> +
> +	/* lower number means higher priority */
> +	if (priority >= ring->priority)
> +		goto out_unlock;
> +
> +	ring->priority = priority;
> +	if (ring->funcs->set_priority)
> +		ring->funcs->set_priority(ring, priority);
> +
> +out_unlock:
> +	spin_unlock(&ring->priority_lock);
> +	return 0;
> +}
> +
> +/**
>    * amdgpu_ring_init - init driver ring struct.
>    *
>    * @adev: amdgpu_device pointer
>    * @ring: amdgpu_ring structure holding ring information
>    * @max_ndw: maximum number of dw for ring alloc
>    * @nop: nop packet for this ring
>    *
>    * Initialize the driver information for the selected ring (all asics).
>    * Returns 0 on success, error on failure.
>    */
> @@ -274,20 +345,22 @@ int amdgpu_ring_init(struct amdgpu_device *adev, struct amdgpu_ring *ring,
>   					    &ring->gpu_addr,
>   					    (void **)&ring->ring);
>   		if (r) {
>   			dev_err(adev->dev, "(%d) ring create failed\n", r);
>   			return r;
>   		}
>   		memset((void *)ring->ring, 0, ring->ring_size);
>   	}
>   	ring->ptr_mask = (ring->ring_size / 4) - 1;
>   	ring->max_dw = max_dw;
> +	ring->priority = AMD_SCHED_PRIORITY_NORMAL;
> +	spin_lock_init(&ring->priority_lock);
>   	INIT_LIST_HEAD(&ring->lru_list);
>   	amdgpu_ring_lru_touch(adev, ring);
>   
>   	if (amdgpu_debugfs_ring_init(adev, ring)) {
>   		DRM_ERROR("Failed to register debugfs file for rings !\n");
>   	}
>   	return 0;
>   }
>   
>   /**
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> index b51bdcd..ee6be0c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> @@ -17,20 +17,21 @@
>    * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
>    * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
>    * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
>    * OTHER DEALINGS IN THE SOFTWARE.
>    *
>    * Authors: Christian König
>    */
>   #ifndef __AMDGPU_RING_H__
>   #define __AMDGPU_RING_H__
>   
> +#include <drm/amdgpu_drm.h>
>   #include "gpu_scheduler.h"
>   
>   /* max number of rings */
>   #define AMDGPU_MAX_RINGS		16
>   #define AMDGPU_MAX_GFX_RINGS		1
>   #define AMDGPU_MAX_COMPUTE_RINGS	8
>   #define AMDGPU_MAX_VCE_RINGS		3
>   
>   /* some special values for the owner field */
>   #define AMDGPU_FENCE_OWNER_UNDEFINED	((void*)0ul)
> @@ -130,20 +131,22 @@ struct amdgpu_ring_funcs {
>   	void (*pad_ib)(struct amdgpu_ring *ring, struct amdgpu_ib *ib);
>   	unsigned (*init_cond_exec)(struct amdgpu_ring *ring);
>   	void (*patch_cond_exec)(struct amdgpu_ring *ring, unsigned offset);
>   	/* note usage for clock and power gating */
>   	void (*begin_use)(struct amdgpu_ring *ring);
>   	void (*end_use)(struct amdgpu_ring *ring);
>   	void (*emit_switch_buffer) (struct amdgpu_ring *ring);
>   	void (*emit_cntxcntl) (struct amdgpu_ring *ring, uint32_t flags);
>   	void (*emit_rreg)(struct amdgpu_ring *ring, uint32_t reg);
>   	void (*emit_wreg)(struct amdgpu_ring *ring, uint32_t reg, uint32_t val);
> +	/* priority functions */
> +	void (*set_priority) (struct amdgpu_ring *ring, int priority);
>   };
>   
>   struct amdgpu_ring {
>   	struct amdgpu_device		*adev;
>   	const struct amdgpu_ring_funcs	*funcs;
>   	struct amdgpu_fence_driver	fence_drv;
>   	struct amd_gpu_scheduler	sched;
>   	struct list_head		lru_list;
>   
>   	struct amdgpu_bo	*ring_obj;
> @@ -164,31 +167,40 @@ struct amdgpu_ring {
>   	struct amdgpu_bo	*mqd_obj;
>   	u32			doorbell_index;
>   	bool			use_doorbell;
>   	unsigned		wptr_offs;
>   	unsigned		fence_offs;
>   	uint64_t		current_ctx;
>   	char			name[16];
>   	unsigned		cond_exe_offs;
>   	u64			cond_exe_gpu_addr;
>   	volatile u32		*cond_exe_cpu_addr;
> +
> +	spinlock_t		priority_lock;
> +	/* protected by priority_lock */
> +	struct amdgpu_job 	*last_job[AMD_SCHED_MAX_PRIORITY];
> +	int			priority;
> +
>   #if defined(CONFIG_DEBUG_FS)
>   	struct dentry *ent;
>   #endif
>   };
>   
>   int amdgpu_ring_is_valid_index(struct amdgpu_device *adev,
>   			       int hw_ip, int ring);
>   int amdgpu_ring_alloc(struct amdgpu_ring *ring, unsigned ndw);
>   void amdgpu_ring_insert_nop(struct amdgpu_ring *ring, uint32_t count);
>   void amdgpu_ring_generic_pad_ib(struct amdgpu_ring *ring, struct amdgpu_ib *ib);
>   void amdgpu_ring_commit(struct amdgpu_ring *ring);
>   void amdgpu_ring_undo(struct amdgpu_ring *ring);
> +int amdgpu_ring_elevate_priority(struct amdgpu_ring *ring, int priority,
> +				 struct amdgpu_job *job);
> +void amdgpu_ring_restore_priority_cb(struct amdgpu_job *job);
>   int amdgpu_ring_init(struct amdgpu_device *adev, struct amdgpu_ring *ring,
>   		     unsigned ring_size, struct amdgpu_irq_src *irq_src,
>   		     unsigned irq_type);
>   void amdgpu_ring_fini(struct amdgpu_ring *ring);
>   int amdgpu_ring_lru_get(struct amdgpu_device *adev, int hw_ip,
>   			struct amdgpu_ring **ring);
>   void amdgpu_ring_lru_touch(struct amdgpu_device *adev, struct amdgpu_ring *ring);
>   
>   #endif




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