On 2017-03-07 06:00 AM, Christian König wrote:
> Am 07.03.2017 um 02:10 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
>> v5: use atomic for tracking job priorities instead of last_job
>>
>> Signed-off-by: Andres Rodriguez <andresx7 at gmail.com>
>
> Two more nit picks and one real problem below.
>
>> ---
>> drivers/gpu/drm/amd/amdgpu/amdgpu_job.c | 8 +++
>> drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c | 82
>> +++++++++++++++++++++++++++
>> drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h | 15 +++++
>> drivers/gpu/drm/amd/scheduler/gpu_scheduler.h | 7 +++
>> 4 files changed, 112 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
>> index 86a1242..bd6fa0f 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
>> @@ -88,20 +88,21 @@ 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);
>> + amdgpu_ring_restore_priority(job);
>> 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 +163,35 @@ 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,
>> + amd_sched_get_job_priority(&job->base),
>> + 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 d655fa4..d67dc69 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
>> @@ -193,20 +193,100 @@ 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 - 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(struct amdgpu_job *job)
>
> Only a nit pick. But just giving job_priority as parameter directly
> here would bring it in line with how amdgpu_ring_elevate_priority()
> works.
>
>> +{
>> + int i;
>> + struct amdgpu_ring *ring = job->ring;
>> + enum amd_sched_priority job_priority;
>> +
>> + if (!ring->funcs->set_priority)
>> + return;
>> +
>> + job_priority = amd_sched_get_job_priority(&job->base);
>> + if (atomic_dec_return(&ring->num_jobs[job_priority]) > 0)
>> + return;
>> +
>> + /* no need to restore if the job is already at the lowest
>> priority */
>> + if (job_priority == AMD_SCHED_PRIORITY_NORMAL)
>> + return;
>> +
>> + spin_lock(&ring->priority_lock);
>> + /* 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
>> + || atomic_read(&ring->num_jobs[i])) {
>> + ring->priority = i;
>> + 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,
>> + enum amd_sched_priority priority,
>> + struct amdgpu_job *job)
>
> As far as I can see the job parameter is superfluous now.
Without the job parameter the function name becomes a little confusing.
I'm also going to rename these to amdgpu_ring_priority_[get/put]() to
correct the above.
-Andres
>
>> +{
>> + if (priority < 0 || priority >= AMD_SCHED_MAX_PRIORITY)
>> + return -EINVAL;
>> +
>> + if (!ring->funcs->set_priority)
>> + return 0;
>> +
>> + atomic_inc(&ring->num_jobs[priority]);
>> +
>> + /* lower number means higher priority */
>> + spin_lock(&ring->priority_lock);
>
> Sorry, could be that I incorrectly suggested that. Double checking the
> set_priority callback you need to take the GRBM mutex to set the
> priority. Don't you?
>
> If that's true this would be illegal cause you take a spin lock first
> and then try to grab a mutex which can cause a deadlock.
>
> BTW: Alex, Felix does anybody of hand know why the GRBM lock is a
> mutex in the first place? Sounds scary to schedule while having the
> hardware in a very specific state.
>
> Regards,
> Christian.
>
>> + if (priority >= ring->priority)
>> + goto out_unlock;
>> +
>> + ring->priority = 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 +354,22 @@ 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..bad40f8 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)
>> @@ -45,20 +46,21 @@ enum amdgpu_ring_type {
>> AMDGPU_RING_TYPE_SDMA,
>> AMDGPU_RING_TYPE_UVD,
>> AMDGPU_RING_TYPE_VCE,
>> AMDGPU_RING_TYPE_KIQ
>> };
>> struct amdgpu_device;
>> struct amdgpu_ring;
>> struct amdgpu_ib;
>> struct amdgpu_cs_parser;
>> +struct amdgpu_job;
>> /*
>> * Fences.
>> */
>> struct amdgpu_fence_driver {
>> uint64_t gpu_addr;
>> volatile uint32_t *cpu_addr;
>> /* sync_seq is protected by ring emission lock */
>> uint32_t sync_seq;
>> atomic_t last_seq;
>> @@ -130,20 +132,23 @@ 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,
>> + enum amd_sched_priority 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 +169,41 @@ 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;
>> +
>> + atomic_t num_jobs[AMD_SCHED_MAX_PRIORITY];
>> + spinlock_t priority_lock;
>> + /* protected by priority_lock */
>> + 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,
>> + enum amd_sched_priority priority,
>> + struct amdgpu_job *job);
>> +void amdgpu_ring_restore_priority(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
>> diff --git a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h
>> b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h
>> index 2e458de..5e25674 100644
>> --- a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h
>> +++ b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h
>> @@ -149,11 +149,18 @@ void amd_sched_fence_slab_fini(void);
>> struct amd_sched_fence *amd_sched_fence_create(
>> struct amd_sched_entity *s_entity, void *owner);
>> void amd_sched_fence_scheduled(struct amd_sched_fence *fence);
>> void amd_sched_fence_finished(struct amd_sched_fence *fence);
>> int amd_sched_job_init(struct amd_sched_job *job,
>> struct amd_gpu_scheduler *sched,
>> struct amd_sched_entity *entity,
>> void *owner);
>> void amd_sched_hw_job_reset(struct amd_gpu_scheduler *sched);
>> void amd_sched_job_recovery(struct amd_gpu_scheduler *sched);
>> +
>> +static inline enum amd_sched_priority
>> +amd_sched_get_job_priority(struct amd_sched_job *job)
>> +{
>> + return (job->s_entity->rq - job->sched->sched_rq);
>> +}
>> +
>> #endif
>
>
