[PATCH] drm/amdgpu: introduce AMDGPU_GEM_CREATE_EXPLICIT_SYNC
Andres Rodriguez
andresx7 at gmail.com
Tue Sep 19 03:12:52 UTC 2017
On 2017-09-18 10:47 PM, zhoucm1 wrote:
>
>
> On 2017年09月19日 07:16, Andres Rodriguez wrote:
>> Introduce a flag to signal that access to a BO will be synchronized
>> through an external mechanism.
>>
>> Currently all buffers shared between contexts are subject to implicit
>> synchronization. However, this is only required for protocols that
>> currently don't support an explicit synchronization mechanism (DRI2/3).
>>
>> This patch introduces the AMDGPU_GEM_CREATE_EXPLICIT_SYNC, so that
>> users can specify when it is safe to disable implicit sync.
>>
>> Signed-off-by: Andres Rodriguez <andresx7 at gmail.com>
>> ---
>> drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 4 +++-
>> drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 4 +++-
>> drivers/gpu/drm/amd/amdgpu/amdgpu_object.h | 8 ++++++++
>> drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c | 8 ++++++--
>> drivers/gpu/drm/amd/amdgpu/amdgpu_sync.h | 3 ++-
>> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 6 ++++--
>> drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 10 ++++++----
>> include/uapi/drm/amdgpu_drm.h | 2 ++
>> 8 files changed, 34 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
>> index db97e78..107533f 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
>> @@ -704,7 +704,9 @@ static int amdgpu_cs_sync_rings(struct
>> amdgpu_cs_parser *p)
>> list_for_each_entry(e, &p->validated, tv.head) {
>> struct reservation_object *resv = e->robj->tbo.resv;
>> - r = amdgpu_sync_resv(p->adev, &p->job->sync, resv, p->filp);
>> + r = amdgpu_sync_resv(p->adev, &p->job->sync, resv,
>> + p->filp,
>> + amdgpu_bo_explicit_sync(e->robj));
>> if (r)
>> return r;
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
>> index b0d45c8..21e9936 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
>> @@ -212,7 +212,9 @@ int amdgpu_gem_create_ioctl(struct drm_device
>> *dev, void *data,
>> AMDGPU_GEM_CREATE_NO_CPU_ACCESS |
>> AMDGPU_GEM_CREATE_CPU_GTT_USWC |
>> AMDGPU_GEM_CREATE_VRAM_CLEARED |
>> - AMDGPU_GEM_CREATE_VM_ALWAYS_VALID))
>> + AMDGPU_GEM_CREATE_VM_ALWAYS_VALID |
>> + AMDGPU_GEM_CREATE_EXPLICIT_SYNC))
>> +
>> return -EINVAL;
>> /* reject invalid gem domains */
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
>> index c26ef53..428aae0 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
>> @@ -193,6 +193,14 @@ static inline bool
>> amdgpu_bo_gpu_accessible(struct amdgpu_bo *bo)
>> }
>> }
>> +/**
>> + * amdgpu_bo_explicit_sync - return whether the bo is explicitly synced
>> + */
>> +static inline bool amdgpu_bo_explicit_sync(struct amdgpu_bo *bo)
>> +{
>> + return bo->flags & AMDGPU_GEM_CREATE_EXPLICIT_SYNC;
>> +}
>> +
>> int amdgpu_bo_create(struct amdgpu_device *adev,
>> unsigned long size, int byte_align,
>> bool kernel, u32 domain, u64 flags,
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
>> index c586f44..6bf4bed 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
>> @@ -169,14 +169,15 @@ int amdgpu_sync_fence(struct amdgpu_device
>> *adev, struct amdgpu_sync *sync,
>> *
>> * @sync: sync object to add fences from reservation object to
>> * @resv: reservation object with embedded fence
>> - * @shared: true if we should only sync to the exclusive fence
>> + * @explicit_sync: true if we should only sync to the exclusive fence
>> *
>> * Sync to the fence
>> */
>> int amdgpu_sync_resv(struct amdgpu_device *adev,
>> struct amdgpu_sync *sync,
>> struct reservation_object *resv,
>> - void *owner)
>> + void *owner,
>> + bool explicit_sync)
> Could you move explicit_sync inside function?
> like:
>
> bool explicit_sync = bo->flags & AMDGPU_GEM_CREATE_EXPLICIT_SYNC;
>
I was thinking of doing something like this originally. Extract the ttm
bo from the resv object, and then get the abo from that. Would've been a
pretty tiny and clean patch.
However, the reservation object is a pointer instead of being embedded
inside the ttm bo. So that path doesn't work.
Passing in a pointer to the full bo is overkill I think. And the
function might be used in cases where the reservation object is not
associated with a specific bo (at least the current interface allows for
that).
That is why I ended up choosing this interface, even though it made the
patch a lot more verbose.
But if you, or anyone, has any suggestions on how to simplify this patch
let me know.
>> {
>> struct reservation_object_list *flist;
>> struct dma_fence *f;
>> @@ -191,6 +192,9 @@ int amdgpu_sync_resv(struct amdgpu_device *adev,
>> f = reservation_object_get_excl(resv);
>> r = amdgpu_sync_fence(adev, sync, f);
>> + if (explicit_sync)
>> + return r;
>> +
> Do you need to move return before syncing excl?
>
I think the exclusive fence always needs to be syncd. My understanding
of TTM is pretty basic, so I might be wrong here.
Regards,
Andres
> Regards,
> David Zhou
>> flist = reservation_object_get_list(resv);
>> if (!flist || r)
>> return r;
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.h
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.h
>> index dc76879..70d7e3a 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.h
>> @@ -45,7 +45,8 @@ int amdgpu_sync_fence(struct amdgpu_device *adev,
>> struct amdgpu_sync *sync,
>> int amdgpu_sync_resv(struct amdgpu_device *adev,
>> struct amdgpu_sync *sync,
>> struct reservation_object *resv,
>> - void *owner);
>> + void *owner,
>> + bool explicit_sync);
>> struct dma_fence *amdgpu_sync_peek_fence(struct amdgpu_sync *sync,
>> struct amdgpu_ring *ring);
>> struct dma_fence *amdgpu_sync_get_fence(struct amdgpu_sync *sync);
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> index c9c059d..18c5662 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> @@ -1510,7 +1510,8 @@ int amdgpu_copy_buffer(struct amdgpu_ring *ring,
>> uint64_t src_offset,
>> job->vm_needs_flush = vm_needs_flush;
>> if (resv) {
>> r = amdgpu_sync_resv(adev, &job->sync, resv,
>> - AMDGPU_FENCE_OWNER_UNDEFINED);
>> + AMDGPU_FENCE_OWNER_UNDEFINED,
>> + false);
>> if (r) {
>> DRM_ERROR("sync failed (%d).\n", r);
>> goto error_free;
>> @@ -1602,7 +1603,8 @@ int amdgpu_fill_buffer(struct amdgpu_bo *bo,
>> if (resv) {
>> r = amdgpu_sync_resv(adev, &job->sync, resv,
>> - AMDGPU_FENCE_OWNER_UNDEFINED);
>> + AMDGPU_FENCE_OWNER_UNDEFINED,
>> + amdgpu_bo_explicit_sync(bo));
>> if (r) {
>> DRM_ERROR("sync failed (%d).\n", r);
>> goto error_free;
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>> index 2df254c..ca9a9b4 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>> @@ -987,7 +987,7 @@ static int amdgpu_vm_wait_pd(struct amdgpu_device
>> *adev, struct amdgpu_vm *vm,
>> int r;
>> amdgpu_sync_create(&sync);
>> - amdgpu_sync_resv(adev, &sync, vm->root.base.bo->tbo.resv, owner);
>> + amdgpu_sync_resv(adev, &sync, vm->root.base.bo->tbo.resv, owner,
>> false);
>> r = amdgpu_sync_wait(&sync, true);
>> amdgpu_sync_free(&sync);
>> @@ -1128,11 +1128,13 @@ static int amdgpu_vm_update_level(struct
>> amdgpu_device *adev,
>> amdgpu_ring_pad_ib(ring, params.ib);
>> amdgpu_sync_resv(adev, &job->sync,
>> parent->base.bo->tbo.resv,
>> - AMDGPU_FENCE_OWNER_VM);
>> + AMDGPU_FENCE_OWNER_VM,
>> + amdgpu_bo_explicit_sync(parent->base.bo));
>
>> if (shadow)
>> amdgpu_sync_resv(adev, &job->sync,
>> shadow->tbo.resv,
>> - AMDGPU_FENCE_OWNER_VM);
>> + AMDGPU_FENCE_OWNER_VM,
>> + amdgpu_bo_explicit_sync(shadow));
>> WARN_ON(params.ib->length_dw > ndw);
>> r = amdgpu_job_submit(job, ring, &vm->entity,
>> @@ -1595,7 +1597,7 @@ static int amdgpu_vm_bo_update_mapping(struct
>> amdgpu_device *adev,
>> goto error_free;
>> r = amdgpu_sync_resv(adev, &job->sync, vm->root.base.bo->tbo.resv,
>> - owner);
>> + owner, amdgpu_bo_explicit_sync(vm->root.base.bo));
>> if (r)
>> goto error_free;
>> diff --git a/include/uapi/drm/amdgpu_drm.h
>> b/include/uapi/drm/amdgpu_drm.h
>> index 69d64e5..96fcde8 100644
>> --- a/include/uapi/drm/amdgpu_drm.h
>> +++ b/include/uapi/drm/amdgpu_drm.h
>> @@ -91,6 +91,8 @@ extern "C" {
>> #define AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS (1 << 5)
>> /* Flag that BO is always valid in this VM */
>> #define AMDGPU_GEM_CREATE_VM_ALWAYS_VALID (1 << 6)
>> +/* Flag that BO sharing will be explicitly synchronized */
>> +#define AMDGPU_GEM_CREATE_EXPLICIT_SYNC (1 << 7)
>> struct drm_amdgpu_gem_create_in {
>> /** the requested memory size */
>
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