[PATCHv2 1/2] drm/amd/amdgpu embed hw_fence into amdgpu_job
Andrey Grodzovsky
andrey.grodzovsky at amd.com
Thu Aug 5 21:13:22 UTC 2021
On 2021-08-05 4:31 a.m., Jingwen Chen wrote:
> From: Jack Zhang <Jack.Zhang1 at amd.com>
>
> Why: Previously hw fence is alloced separately with job.
> It caused historical lifetime issues and corner cases.
> The ideal situation is to take fence to manage both job
> and fence's lifetime, and simplify the design of gpu-scheduler.
>
> How:
> We propose to embed hw_fence into amdgpu_job.
> 1. We cover the normal job submission by this method.
> 2. For ib_test, and submit without a parent job keep the
> legacy way to create a hw fence separately.
> v2:
> use AMDGPU_FENCE_FLAG_EMBED_IN_JOB_BIT to show that the fence is
> embeded in a job.
>
> Signed-off-by: Jingwen Chen <Jingwen.Chen2 at amd.com>
> Signed-off-by: Jack Zhang <Jack.Zhang7 at hotmail.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c | 1 -
> drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 2 +-
> drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c | 63 ++++++++++++++++-----
> drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c | 2 +-
> drivers/gpu/drm/amd/amdgpu/amdgpu_job.c | 35 ++++++++----
> drivers/gpu/drm/amd/amdgpu/amdgpu_job.h | 4 +-
> drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h | 5 +-
> drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 2 +-
> 8 files changed, 84 insertions(+), 30 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
> index 7b46ba551cb2..3003ee1c9487 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
> @@ -714,7 +714,6 @@ int amdgpu_amdkfd_submit_ib(struct kgd_dev *kgd, enum kgd_engine_type engine,
> ret = dma_fence_wait(f, false);
>
> err_ib_sched:
> - dma_fence_put(f);
> amdgpu_job_free(job);
> err:
> return ret;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> index 536005bff24a..277128846dd1 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> @@ -1414,7 +1414,7 @@ static void amdgpu_ib_preempt_mark_partial_job(struct amdgpu_ring *ring)
> continue;
> }
> job = to_amdgpu_job(s_job);
> - if (preempted && job->fence == fence)
> + if (preempted && (&job->hw_fence) == fence)
> /* mark the job as preempted */
> job->preemption_status |= AMDGPU_IB_PREEMPTED;
> }
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
> index 7495911516c2..5e29d797a265 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
> @@ -129,30 +129,46 @@ static u32 amdgpu_fence_read(struct amdgpu_ring *ring)
> *
> * @ring: ring the fence is associated with
> * @f: resulting fence object
> + * @job: job the fence is embeded in
> * @flags: flags to pass into the subordinate .emit_fence() call
> *
> * Emits a fence command on the requested ring (all asics).
> * Returns 0 on success, -ENOMEM on failure.
> */
> -int amdgpu_fence_emit(struct amdgpu_ring *ring, struct dma_fence **f,
> +int amdgpu_fence_emit(struct amdgpu_ring *ring, struct dma_fence **f, struct amdgpu_job *job,
> unsigned flags)
> {
> struct amdgpu_device *adev = ring->adev;
> - struct amdgpu_fence *fence;
> + struct dma_fence *fence;
> + struct amdgpu_fence *am_fence;
> struct dma_fence __rcu **ptr;
> uint32_t seq;
> int r;
>
> - fence = kmem_cache_alloc(amdgpu_fence_slab, GFP_KERNEL);
> - if (fence == NULL)
> - return -ENOMEM;
> + if (job == NULL) {
> + /* create a sperate hw fence */
> + am_fence = kmem_cache_alloc(amdgpu_fence_slab, GFP_ATOMIC);
> + if (am_fence == NULL)
> + return -ENOMEM;
> + fence = &am_fence->base;
> + am_fence->ring = ring;
> + } else {
> + /* take use of job-embedded fence */
> + fence = &job->hw_fence;
> + job->ring = ring;
If you would make hw_fence of type amdgpu_fence
you could probably avoid the special job->ring = ring
See more in related comment at the bottom
> + }
>
> seq = ++ring->fence_drv.sync_seq;
> - fence->ring = ring;
> - dma_fence_init(&fence->base, &amdgpu_fence_ops,
> + dma_fence_init(fence, &amdgpu_fence_ops,
> &ring->fence_drv.lock,
> adev->fence_context + ring->idx,
> seq);
> +
> + if (job != NULL) {
> + /* mark this fence has a parent job */
> + set_bit(AMDGPU_FENCE_FLAG_EMBED_IN_JOB_BIT, &fence->flags);
> + }
> +
> amdgpu_ring_emit_fence(ring, ring->fence_drv.gpu_addr,
> seq, flags | AMDGPU_FENCE_FLAG_INT);
> pm_runtime_get_noresume(adev_to_drm(adev)->dev);
> @@ -175,9 +191,9 @@ int amdgpu_fence_emit(struct amdgpu_ring *ring, struct dma_fence **f,
> /* This function can't be called concurrently anyway, otherwise
> * emitting the fence would mess up the hardware ring buffer.
> */
> - rcu_assign_pointer(*ptr, dma_fence_get(&fence->base));
> + rcu_assign_pointer(*ptr, dma_fence_get(fence));
>
> - *f = &fence->base;
> + *f = fence;
>
> return 0;
> }
> @@ -621,8 +637,16 @@ static const char *amdgpu_fence_get_driver_name(struct dma_fence *fence)
>
> static const char *amdgpu_fence_get_timeline_name(struct dma_fence *f)
> {
> - struct amdgpu_fence *fence = to_amdgpu_fence(f);
> - return (const char *)fence->ring->name;
> + struct amdgpu_ring *ring;
> +
> + if (test_bit(AMDGPU_FENCE_FLAG_EMBED_IN_JOB_BIT, &f->flags)) {
> + struct amdgpu_job *job = container_of(f, struct amdgpu_job, hw_fence);
> +
> + ring = job->ring;
> + } else {
> + ring = to_amdgpu_fence(f)->ring;
> + }
Same as above
> + return (const char *)ring->name;
> }
>
> /**
> @@ -656,8 +680,20 @@ static bool amdgpu_fence_enable_signaling(struct dma_fence *f)
> static void amdgpu_fence_free(struct rcu_head *rcu)
> {
> struct dma_fence *f = container_of(rcu, struct dma_fence, rcu);
> - struct amdgpu_fence *fence = to_amdgpu_fence(f);
> - kmem_cache_free(amdgpu_fence_slab, fence);
> +
> + if (test_bit(AMDGPU_FENCE_FLAG_EMBED_IN_JOB_BIT, &f->flags)) {
> + /* free job if fence has a parent job */
> + struct amdgpu_job *job;
> +
> + job = container_of(f, struct amdgpu_job, hw_fence);
> + kfree(job);
> + } else {
> + /* free fence_slab if it's separated fence*/
> + struct amdgpu_fence *fence;
> +
> + fence = to_amdgpu_fence(f);
> + kmem_cache_free(amdgpu_fence_slab, fence);
> + }
> }
>
> /**
> @@ -680,6 +716,7 @@ static const struct dma_fence_ops amdgpu_fence_ops = {
> .release = amdgpu_fence_release,
> };
>
> +
> /*
> * Fence debugfs
> */
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
> index ec65ab0ddf89..c076a6b9a5a2 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
> @@ -262,7 +262,7 @@ int amdgpu_ib_schedule(struct amdgpu_ring *ring, unsigned num_ibs,
> fence_flags | AMDGPU_FENCE_FLAG_64BIT);
> }
>
> - r = amdgpu_fence_emit(ring, f, fence_flags);
> + r = amdgpu_fence_emit(ring, f, job, fence_flags);
> if (r) {
> dev_err(adev->dev, "failed to emit fence (%d)\n", r);
> if (job && job->vmid)
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
> index d33e6d97cc89..65a395060de2 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
> @@ -127,11 +127,16 @@ void amdgpu_job_free_resources(struct amdgpu_job *job)
> {
> struct amdgpu_ring *ring = to_amdgpu_ring(job->base.sched);
> struct dma_fence *f;
> + struct dma_fence *hw_fence;
> unsigned i;
>
> - /* use sched fence if available */
> - f = job->base.s_fence ? &job->base.s_fence->finished : job->fence;
> + if (job->hw_fence.ops == NULL)
> + hw_fence = job->external_hw_fence;
> + else
> + hw_fence = &job->hw_fence;
>
> + /* use sched fence if available */
> + f = job->base.s_fence ? &job->base.s_fence->finished : hw_fence;
> for (i = 0; i < job->num_ibs; ++i)
> amdgpu_ib_free(ring->adev, &job->ibs[i], f);
> }
> @@ -142,20 +147,27 @@ static void amdgpu_job_free_cb(struct drm_sched_job *s_job)
>
> drm_sched_job_cleanup(s_job);
>
> - dma_fence_put(job->fence);
> amdgpu_sync_free(&job->sync);
> amdgpu_sync_free(&job->sched_sync);
> - kfree(job);
> +
> + /* only put the hw fence if has embedded fence */
> + if (job->hw_fence.ops != NULL)
> + dma_fence_put(&job->hw_fence);
> + else
> + kfree(job);
> }
>
> void amdgpu_job_free(struct amdgpu_job *job)
> {
> amdgpu_job_free_resources(job);
> -
> - dma_fence_put(job->fence);
> amdgpu_sync_free(&job->sync);
> amdgpu_sync_free(&job->sched_sync);
> - kfree(job);
> +
> + /* only put the hw fence if has embedded fence */
> + if (job->hw_fence.ops != NULL)
> + dma_fence_put(&job->hw_fence);
> + else
> + kfree(job);
> }
>
> int amdgpu_job_submit(struct amdgpu_job *job, struct drm_sched_entity *entity,
> @@ -184,11 +196,14 @@ int amdgpu_job_submit_direct(struct amdgpu_job *job, struct amdgpu_ring *ring,
>
> job->base.sched = &ring->sched;
> r = amdgpu_ib_schedule(ring, job->num_ibs, job->ibs, NULL, fence);
> - job->fence = dma_fence_get(*fence);
> + /* record external_hw_fence for direct submit */
> + job->external_hw_fence = dma_fence_get(*fence);
> if (r)
> return r;
>
> amdgpu_job_free(job);
> + dma_fence_put(*fence);
> +
> return 0;
> }
>
> @@ -246,10 +261,8 @@ static struct dma_fence *amdgpu_job_run(struct drm_sched_job *sched_job)
> 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);
>
> + dma_fence_get(fence);
> amdgpu_job_free_resources(job);
>
> fence = r ? ERR_PTR(r) : fence;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.h
> index 81caac9b958a..92324c978534 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.h
> @@ -46,7 +46,9 @@ struct amdgpu_job {
> struct amdgpu_sync sync;
> struct amdgpu_sync sched_sync;
> struct amdgpu_ib *ibs;
> - struct dma_fence *fence; /* the hw fence */
> + struct dma_fence hw_fence;
> + struct amdgpu_ring *ring;
Why not instead of 2 fields above just embed struct amdgpu_fence as
hw_fence and by this save the extra 'ring' field handling ?
Andrey
> + struct dma_fence *external_hw_fence;
> uint32_t preamble_status;
> uint32_t preemption_status;
> uint32_t num_ibs;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> index 9c11ced4312c..03d4b29a76d6 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> @@ -48,6 +48,9 @@
> #define AMDGPU_FENCE_FLAG_INT (1 << 1)
> #define AMDGPU_FENCE_FLAG_TC_WB_ONLY (1 << 2)
>
> +/* fence flag bit to indicate the face is embeded in job*/
> +#define AMDGPU_FENCE_FLAG_EMBED_IN_JOB_BIT (DMA_FENCE_FLAG_USER_BITS + 1)
> +
> #define to_amdgpu_ring(s) container_of((s), struct amdgpu_ring, sched)
>
> #define AMDGPU_IB_POOL_SIZE (1024 * 1024)
> @@ -118,7 +121,7 @@ void amdgpu_fence_driver_hw_init(struct amdgpu_device *adev);
> void amdgpu_fence_driver_hw_fini(struct amdgpu_device *adev);
> int amdgpu_fence_driver_sw_init(struct amdgpu_device *adev);
> void amdgpu_fence_driver_sw_fini(struct amdgpu_device *adev);
> -int amdgpu_fence_emit(struct amdgpu_ring *ring, struct dma_fence **fence,
> +int amdgpu_fence_emit(struct amdgpu_ring *ring, struct dma_fence **fence, struct amdgpu_job *job,
> unsigned flags);
> int amdgpu_fence_emit_polling(struct amdgpu_ring *ring, uint32_t *s,
> uint32_t timeout);
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index 2a88ed5d983b..2af8860d74cc 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -1218,7 +1218,7 @@ int amdgpu_vm_flush(struct amdgpu_ring *ring, struct amdgpu_job *job,
> amdgpu_gmc_emit_pasid_mapping(ring, job->vmid, job->pasid);
>
> if (vm_flush_needed || pasid_mapping_needed) {
> - r = amdgpu_fence_emit(ring, &fence, 0);
> + r = amdgpu_fence_emit(ring, &fence, NULL, 0);
> if (r)
> return r;
> }
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