[PATCH 19/22] drm/amdgpu: add framework for HW specific priority settings

Andres Rodriguez andresx7 at gmail.com
Thu Mar 2 06:45:09 UTC 2017



On 2017-03-01 12:44 PM, Andres Rodriguez wrote:
>
>
> On 2017-03-01 10:49 AM, Alex Deucher wrote:
>> On Wed, Mar 1, 2017 at 2:27 AM, zhoucm1 <david1.zhou at amd.com> wrote:
>>>
>>> On 2017年03月01日 06:14, Andres Rodriguez wrote:
>>>> 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.
>>>>
>>>> Signed-off-by: Andres Rodriguez <andresx7 at gmail.com>
>>>> ---
>>>>    drivers/gpu/drm/amd/amdgpu/amdgpu.h      |  4 +-
>>>>    drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c   |  2 +-
>>>>    drivers/gpu/drm/amd/amdgpu/amdgpu_job.c  | 10 ++++-
>>>>    drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c | 71
>>>> ++++++++++++++++++++++++++++++++
>>>>    drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h | 11 +++++
>>>>    5 files changed, 94 insertions(+), 4 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>>> index 366f6d3..0676495 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);
>>>>    @@ -990,20 +990,22 @@ 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 */
>>>> +       struct dma_fence_cb     cb;
>>>> +       int                     priority;
>>>>          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..45b3c90 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, AMDGPU_CTX_PRIORITY_NORMAL, job,
>>>> NULL);
>>>>          if (r)
>>>>                  return r;
>>>>          r = amdgpu_ib_get(adev, NULL, size, &(*job)->ibs[0]);
>>>>          if (r)
>>>>                  kfree(*job);
>>>>          return r;
>>>>    }
>>>>    @@ -170,20 +171,25 @@ static struct dma_fence *amdgpu_job_run(struct
>>>> amd_sched_job *sched_job)
>>>>          BUG_ON(amdgpu_sync_peek_fence(&job->sync, NULL));
>>>>          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);
>>>> +
>>>> +       r = amdgpu_ring_elevate_priority(job->ring, job->priority,
>>>> job);
>>>> +       if (r)
>>>> +               DRM_ERROR("Failed to set job priority (%d)\n", r);
>>> elevate priority of ring is for this job, right?
>>> you're setting priority by mmio method and restore priority by fence cb,
>>> your method isn't precise. I have some comments:
>>> 1. seems we should elevate_priority before amdgpu_ib_schedule, so
>>> that the
>>> ring is proper priority for this submission.
> Yeah thanks for the catch on that. This might result in the first
> packets being emitted with a new_wave_priority lower than desired and
> introduce extra delay.
>>> 2. can we put setting of registers of SPI into ring buffer as a command
>>> frame? evevate_priority setting is front of a command frame and
>>> restore_priority is end of frame.
> We can't do it on the ring because we need any work that is already
> committed to the ring the inherit the highest priority. Otherwise the
> high priority work would have to wait for the regular priority work (to
> complete at regular priority latency) before it can begin.
>
> For more details see my reply to Christian's email regarding this topic.
>> We should probably check if changing the queue priority requires that
>> the engine be idle as well.  I vaguely recall there being a packet for
>> some of this that was added for HSA.
> +Jay
>
> Hey Jay,
>
> Do you have more details on this?
>
> I wrote these patches under the assumption that changing the priority
> while the engine is busy was allowed, but that it would not have any
> effect for waves that have already been emitted.
>
> Would changing the priorities while the engines are active cause any
> hangs or bad side effects?
>>
>> Alex
>>
>>> 3. if no priority exchanges, we can skip setting for priority for
>>> command
>>> submission.
> I originally had a check that skipped set_priority() if the priorities
> matched, but I decided to remove it.
>
> The reason is that while no changes to the HW state may need to happen,
> the implementation may need to track extra metadata about who is
> executing high priority work on the ring. Therefore whether the
> operation is a noop or not should be decided by the specific
> implementation.
>
> Having said that, I think gfx_v8_0_ring_set_priority_compute() can be
> improved to skip more work. So I'll apply your suggestion there.

Apparently I was misremembering an old implementation of cu_reserve().

The current patch already does what you requested. Refer to the 
following code in  amdgpu_ring_elevate_priority():

if (priority <= ring->priority)
                goto out_unlock;

>
>>>
>>> Regards,
>>> David Zhou
>>>
>>>> +
>>>>          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 80cb051..12bc7a9 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
>>>> @@ -192,20 +192,89 @@ void amdgpu_ring_commit(struct amdgpu_ring *ring)
>>>>     * Reset the driver's copy of the wptr (all asics).
>>>>     */
>>>>    void amdgpu_ring_undo(struct amdgpu_ring *ring)
>>>>    {
>>>>          ring->wptr = ring->wptr_old;
>>>>          if (ring->funcs->end_use)
>>>>                  ring->funcs->end_use(ring);
>>>>    }
>>>>    +static void amdgpu_ring_restore_priority_cb(struct dma_fence *f,
>>>> +                                           struct dma_fence_cb *cb)
>>>> +{
>>>> +       int i;
>>>> +       struct amdgpu_job *cb_job =
>>>> +               container_of(cb, struct amdgpu_job, cb);
>>>> +       struct amdgpu_ring *ring = cb_job->ring;
>>>> +
>>>> +       spin_lock(&ring->priority_lock);
>>>> +
>>>> +       /* remove ourselves from the list if necessary */
>>>> +       if (cb_job == ring->last_job[cb_job->priority])
>>>> +               ring->last_job[cb_job->priority] = NULL;
>>>> +
>>>> +       /* something higher prio is executing, no need to decay */
>>>> +       if (ring->priority > cb_job->priority)
>>>> +               goto out_unlock;
>>>> +
>>>> +       /* decay priority to the next level with a job available */
>>>> +       for (i = cb_job->priority; i >= 0; i--) {
>>>> +               if (i == AMDGPU_CTX_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);
>>>> +}
>>>> +
>>>> +/**
>>>> + * 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 >= AMDGPU_CTX_PRIORITY_NUM)
>>>> +               return -EINVAL;
>>>> +
>>>> +       spin_lock(&ring->priority_lock);
>>>> +       ring->last_job[priority] = job;
>>>> +
>>>> +       if (priority <= ring->priority)
>>>> +               goto out_unlock;
>>>> +
>>>> +       ring->priority = priority;
>>>> +       if (ring->funcs->set_priority)
>>>> +               ring->funcs->set_priority(ring, priority);
>>>> +
>>>> +       dma_fence_add_callback(job->fence, &job->cb,
>>>> +                              amdgpu_ring_restore_priority_cb);
>>>> +
>>>> +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.
>>>> @@ -275,20 +344,22 @@ int amdgpu_ring_init(struct amdgpu_device *adev,
>>>> struct amdgpu_ring *ring,
>>>>                                              (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->hw_ip = hw_ip;
>>>> +       ring->priority = AMDGPU_CTX_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 ecdd87c..befc29f 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;
>>>> @@ -165,31 +168,39 @@ 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[AMDGPU_CTX_PRIORITY_NUM];
>>>> +       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);
>>>>    int amdgpu_ring_init(struct amdgpu_device *adev, struct amdgpu_ring
>>>> *ring,
>>>>                       int hw_ip, 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
>>>
>>> _______________________________________________
>>> amd-gfx mailing list
>>> amd-gfx at lists.freedesktop.org
>>> https://lists.freedesktop.org/mailman/listinfo/amd-gfx
>


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