Am 10.05.2017 um 11:00 schrieb zhoucm1:
>
>
> On 2017å¹´05æ??10æ?¥ 16:50, Christian König wrote:
>> Am 10.05.2017 um 10:38 schrieb zhoucm1:
>>>
>>>
>>> On 2017å¹´05æ??10æ?¥ 16:26, Christian König wrote:
>>>> Am 10.05.2017 um 09:31 schrieb Chunming Zhou:
>>>>> this is an improvement for previous patch, the sched_sync is to
>>>>> store fence
>>>>> that could be skipped as scheduled, when job is executed, we
>>>>> didn't need
>>>>> pipeline_sync if all fences in sched_sync are signalled, otherwise
>>>>> insert
>>>>> pipeline_sync still.
>>>>>
>>>>> Change-Id: I26d3a2794272ba94b25753d4bf367326d12f6939
>>>>> Signed-off-by: Chunming Zhou <David1.Zhou at amd.com>
>>>>> ---
>>>>> drivers/gpu/drm/amd/amdgpu/amdgpu.h | 1 +
>>>>> drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c | 7 ++++++-
>>>>> drivers/gpu/drm/amd/amdgpu/amdgpu_job.c | 5 ++++-
>>>>> 3 files changed, 11 insertions(+), 2 deletions(-)
>>>>>
>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>>>> index 787acd7..ef018bf 100644
>>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>>>> @@ -1162,6 +1162,7 @@ struct amdgpu_job {
>>>>> struct amdgpu_vm *vm;
>>>>> struct amdgpu_ring *ring;
>>>>> struct amdgpu_sync sync;
>>>>> + struct amdgpu_sync sched_sync;
>>>>> struct amdgpu_ib *ibs;
>>>>> struct fence *fence; /* the hw fence */
>>>>> uint32_t preamble_status;
>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
>>>>> index 2c6624d..86ad507 100644
>>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
>>>>> @@ -121,6 +121,7 @@ int amdgpu_ib_schedule(struct amdgpu_ring
>>>>> *ring, unsigned num_ibs,
>>>>> {
>>>>> struct amdgpu_device *adev = ring->adev;
>>>>> struct amdgpu_ib *ib = &ibs[0];
>>>>> + struct fence *tmp;
>>>>> bool skip_preamble, need_ctx_switch;
>>>>> unsigned patch_offset = ~0;
>>>>> struct amdgpu_vm *vm;
>>>>> @@ -167,8 +168,12 @@ int amdgpu_ib_schedule(struct amdgpu_ring
>>>>> *ring, unsigned num_ibs,
>>>>> return r;
>>>>> }
>>>>> - if (ring->funcs->emit_pipeline_sync && job &&
>>>>> job->need_pipeline_sync)
>>>>> + if (ring->funcs->emit_pipeline_sync && job &&
>>>>> + (tmp = amdgpu_sync_get_fence(&job->sched_sync))) {
>>>>> + job->need_pipeline_sync = true;
>>>>> amdgpu_ring_emit_pipeline_sync(ring);
>>>>> + fence_put(tmp);
>>>>> + }
>>>>> if (vm) {
>>>>> amdgpu_ring_insert_nop(ring, extra_nop); /* prevent CE
>>>>> go too fast than DE */
>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
>>>>> index cfa97ab..fa0c8b1 100644
>>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
>>>>> @@ -60,6 +60,7 @@ int amdgpu_job_alloc(struct amdgpu_device *adev,
>>>>> unsigned num_ibs,
>>>>> (*job)->need_pipeline_sync = false;
>>>>> amdgpu_sync_create(&(*job)->sync);
>>>>> + amdgpu_sync_create(&(*job)->sched_sync);
>>>>> return 0;
>>>>> }
>>>>> @@ -98,6 +99,7 @@ static void amdgpu_job_free_cb(struct
>>>>> amd_sched_job *s_job)
>>>>> fence_put(job->fence);
>>>>> amdgpu_sync_free(&job->sync);
>>>>> + amdgpu_sync_free(&job->sched_sync);
>>>>> kfree(job);
>>>>> }
>>>>> @@ -107,6 +109,7 @@ void amdgpu_job_free(struct amdgpu_job *job)
>>>>> fence_put(job->fence);
>>>>> amdgpu_sync_free(&job->sync);
>>>>> + amdgpu_sync_free(&job->sched_sync);
>>>>> kfree(job);
>>>>> }
>>>>> @@ -154,7 +157,7 @@ static struct fence
>>>>> *amdgpu_job_dependency(struct amd_sched_job *sched_job)
>>>>> }
>>>>> if (amd_sched_dependency_optimized(fence,
>>>>> sched_job->s_entity))
>>>>> - job->need_pipeline_sync = true;
>>>>> + amdgpu_sync_fence(job->adev, &job->sched_sync, fence);
>>>>
>>>> This can result in an -ENOMEM
>>> will handle it.
>>>> and additional to that we only need to remember the last fence
>>>> optimized like this, not all of them.
>>>>
>>>> So just keep the last one found here in job->sched_fence instead.
>>> I guess this isn't enough.
>>> The dependency is not in order when calling, so the last one is not
>>> always the last scheduled fence.
>>> And they could be sched fence not hw fence, although they are
>>> handled by same hw ring, but the sched fence context isn't same.
>>> so we still need sched_sync here, right?
>>
>> No, amdgpu_job_dependency is only called again when the returned
>> fence is signaled (or scheduled on the same ring).
> Let use give an example for it:
> Assume job->sync has two fences(fenceA and fenceB) which could be
> scheduled. fenceA is from entity1, fenceB is from entity2, but both
> for gfx engine, but fenceA could be submitted to hw ring behind fenceB.
> the order in job->sync list is: others---->fenceA---->fenceB--->others.
> when calling amdgpu_job_dependency, fenceA will be checked first, and
> then fenceB.
>
> If following your proposal, we only store fenceB, but fenceA is the
> later. Which isn't expected.
Ah! Indeed, I didn't realized that the dependent fence could have
already been scheduled.
Mhm, how are we going to handle the out of memory situation then? Sine
we are inside a kernel thread we are not supposed to fail at this point.
Regards,
Christian.
>
>
> Regards,
> David Zhou
>>
>> So when this is called and you find that you need to wait for another
>> fence the order is guaranteed.
>>
>> Regards,
>> Christian.
>>
>>>
>>> Regards,
>>> David zhou
>>>>
>>>> Regards,
>>>> Christian.
>>>>
>>>>> return fence;
>>>>> }
>>>>
>>>>
>>>
>>
>
