* Re: [PATCH] drm/msm: add trace_dma_fence_emit to msm_gpu_submit
@ 2022-04-09 14:33 ` Christian König
0 siblings, 0 replies; 12+ messages in thread
From: Christian König @ 2022-04-09 14:33 UTC (permalink / raw)
To: Chia-I Wu, freedreno
Cc: dri-devel, Sean Paul, Abhinav Kumar, David Airlie, Sumit Semwal,
linux-arm-msm, Daniel Vetter, Rob Clark
Am 08.04.22 um 23:12 schrieb Chia-I Wu:
> In practice, trace_dma_fence_init is good enough and almost no driver
> calls trace_dma_fence_emit. But this is still more correct in theory.
Well, the reason why basically no driver is calling this is because it
is pretty much deprecated.
We do have a case in the GPU scheduler where it makes sense to distinct
between init and emit, but it doesn't really matter for drivers.
So I'm not sure if it's a good idea to add that here.
Regards,
Christian.
>
> Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
> Cc: Rob Clark <robdclark@chromium.org>
> ---
> drivers/gpu/drm/msm/msm_gpu.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
> index faf0c242874e..a82193f41ea2 100644
> --- a/drivers/gpu/drm/msm/msm_gpu.c
> +++ b/drivers/gpu/drm/msm/msm_gpu.c
> @@ -15,6 +15,7 @@
> #include <linux/string_helpers.h>
> #include <linux/devcoredump.h>
> #include <linux/sched/task.h>
> +#include <trace/events/dma_fence.h>
>
> /*
> * Power Management:
> @@ -769,6 +770,7 @@ void msm_gpu_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit)
> gpu->active_submits++;
> mutex_unlock(&gpu->active_lock);
>
> + trace_dma_fence_emit(submit->hw_fence);
> gpu->funcs->submit(gpu, submit);
> gpu->cur_ctx_seqno = submit->queue->ctx->seqno;
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] drm/msm: add trace_dma_fence_emit to msm_gpu_submit
2022-04-09 14:33 ` Christian König
@ 2022-04-09 17:45 ` Chia-I Wu
-1 siblings, 0 replies; 12+ messages in thread
From: Chia-I Wu @ 2022-04-09 17:45 UTC (permalink / raw)
To: Christian König
Cc: freedreno, ML dri-devel, Sean Paul, Abhinav Kumar, David Airlie,
Sumit Semwal, linux-arm-msm, Daniel Vetter, Rob Clark
On Sat, Apr 9, 2022 at 7:33 AM Christian König <christian.koenig@amd.com> wrote:
>
> Am 08.04.22 um 23:12 schrieb Chia-I Wu:
> > In practice, trace_dma_fence_init is good enough and almost no driver
> > calls trace_dma_fence_emit. But this is still more correct in theory.
>
> Well, the reason why basically no driver is calling this is because it
> is pretty much deprecated.
Why is it considered deprecated? trace_dma_fence_{emit,signaled} are
useful to visualize fence timelines. I am actually less sure about
how trace_dma_fence_{init,destroy} are used.
Is it because trace_dma_fence_init is called automatically, and is
good enough most of the time?
>
> We do have a case in the GPU scheduler where it makes sense to distinct
> between init and emit, but it doesn't really matter for drivers.
virtio also has a case where init and emit can be far apart, when the
host cannot process commands fast enough and there is no space in
virtqueue.
>
> So I'm not sure if it's a good idea to add that here.
>
> Regards,
> Christian.
>
> >
> > Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
> > Cc: Rob Clark <robdclark@chromium.org>
> > ---
> > drivers/gpu/drm/msm/msm_gpu.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
> > index faf0c242874e..a82193f41ea2 100644
> > --- a/drivers/gpu/drm/msm/msm_gpu.c
> > +++ b/drivers/gpu/drm/msm/msm_gpu.c
> > @@ -15,6 +15,7 @@
> > #include <linux/string_helpers.h>
> > #include <linux/devcoredump.h>
> > #include <linux/sched/task.h>
> > +#include <trace/events/dma_fence.h>
> >
> > /*
> > * Power Management:
> > @@ -769,6 +770,7 @@ void msm_gpu_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit)
> > gpu->active_submits++;
> > mutex_unlock(&gpu->active_lock);
> >
> > + trace_dma_fence_emit(submit->hw_fence);
> > gpu->funcs->submit(gpu, submit);
> > gpu->cur_ctx_seqno = submit->queue->ctx->seqno;
> >
>
^ permalink raw reply [flat|nested] 12+ messages in thread* Re: [PATCH] drm/msm: add trace_dma_fence_emit to msm_gpu_submit
@ 2022-04-09 17:45 ` Chia-I Wu
0 siblings, 0 replies; 12+ messages in thread
From: Chia-I Wu @ 2022-04-09 17:45 UTC (permalink / raw)
To: Christian König
Cc: Rob Clark, David Airlie, freedreno, Abhinav Kumar, ML dri-devel,
linux-arm-msm, Sean Paul, Sumit Semwal
On Sat, Apr 9, 2022 at 7:33 AM Christian König <christian.koenig@amd.com> wrote:
>
> Am 08.04.22 um 23:12 schrieb Chia-I Wu:
> > In practice, trace_dma_fence_init is good enough and almost no driver
> > calls trace_dma_fence_emit. But this is still more correct in theory.
>
> Well, the reason why basically no driver is calling this is because it
> is pretty much deprecated.
Why is it considered deprecated? trace_dma_fence_{emit,signaled} are
useful to visualize fence timelines. I am actually less sure about
how trace_dma_fence_{init,destroy} are used.
Is it because trace_dma_fence_init is called automatically, and is
good enough most of the time?
>
> We do have a case in the GPU scheduler where it makes sense to distinct
> between init and emit, but it doesn't really matter for drivers.
virtio also has a case where init and emit can be far apart, when the
host cannot process commands fast enough and there is no space in
virtqueue.
>
> So I'm not sure if it's a good idea to add that here.
>
> Regards,
> Christian.
>
> >
> > Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
> > Cc: Rob Clark <robdclark@chromium.org>
> > ---
> > drivers/gpu/drm/msm/msm_gpu.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
> > index faf0c242874e..a82193f41ea2 100644
> > --- a/drivers/gpu/drm/msm/msm_gpu.c
> > +++ b/drivers/gpu/drm/msm/msm_gpu.c
> > @@ -15,6 +15,7 @@
> > #include <linux/string_helpers.h>
> > #include <linux/devcoredump.h>
> > #include <linux/sched/task.h>
> > +#include <trace/events/dma_fence.h>
> >
> > /*
> > * Power Management:
> > @@ -769,6 +770,7 @@ void msm_gpu_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit)
> > gpu->active_submits++;
> > mutex_unlock(&gpu->active_lock);
> >
> > + trace_dma_fence_emit(submit->hw_fence);
> > gpu->funcs->submit(gpu, submit);
> > gpu->cur_ctx_seqno = submit->queue->ctx->seqno;
> >
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] drm/msm: add trace_dma_fence_emit to msm_gpu_submit
2022-04-09 14:33 ` Christian König
@ 2022-04-12 19:41 ` Rob Clark
-1 siblings, 0 replies; 12+ messages in thread
From: Rob Clark @ 2022-04-12 19:41 UTC (permalink / raw)
To: Christian König
Cc: David Airlie, freedreno, Abhinav Kumar, dri-devel, Sumit Semwal,
linux-arm-msm, Sean Paul
On Sat, Apr 9, 2022 at 7:33 AM Christian König <christian.koenig@amd.com> wrote:
>
> Am 08.04.22 um 23:12 schrieb Chia-I Wu:
> > In practice, trace_dma_fence_init is good enough and almost no driver
> > calls trace_dma_fence_emit. But this is still more correct in theory.
>
> Well, the reason why basically no driver is calling this is because it
> is pretty much deprecated.
>
> We do have a case in the GPU scheduler where it makes sense to distinct
> between init and emit, but it doesn't really matter for drivers.
>
> So I'm not sure if it's a good idea to add that here.
visualization can't easily differentiate between drivers/timelines
where the split matters and ones where it doesn't.. IMO it is better
to just have the extra trace even in the cases where it comes at the
same time as the init trace
BR,
-R
> Regards,
> Christian.
>
> >
> > Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
> > Cc: Rob Clark <robdclark@chromium.org>
> > ---
> > drivers/gpu/drm/msm/msm_gpu.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
> > index faf0c242874e..a82193f41ea2 100644
> > --- a/drivers/gpu/drm/msm/msm_gpu.c
> > +++ b/drivers/gpu/drm/msm/msm_gpu.c
> > @@ -15,6 +15,7 @@
> > #include <linux/string_helpers.h>
> > #include <linux/devcoredump.h>
> > #include <linux/sched/task.h>
> > +#include <trace/events/dma_fence.h>
> >
> > /*
> > * Power Management:
> > @@ -769,6 +770,7 @@ void msm_gpu_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit)
> > gpu->active_submits++;
> > mutex_unlock(&gpu->active_lock);
> >
> > + trace_dma_fence_emit(submit->hw_fence);
> > gpu->funcs->submit(gpu, submit);
> > gpu->cur_ctx_seqno = submit->queue->ctx->seqno;
> >
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] drm/msm: add trace_dma_fence_emit to msm_gpu_submit
@ 2022-04-12 19:41 ` Rob Clark
0 siblings, 0 replies; 12+ messages in thread
From: Rob Clark @ 2022-04-12 19:41 UTC (permalink / raw)
To: Christian König
Cc: Chia-I Wu, freedreno, dri-devel, Sean Paul, Abhinav Kumar,
David Airlie, Sumit Semwal, linux-arm-msm, Daniel Vetter
On Sat, Apr 9, 2022 at 7:33 AM Christian König <christian.koenig@amd.com> wrote:
>
> Am 08.04.22 um 23:12 schrieb Chia-I Wu:
> > In practice, trace_dma_fence_init is good enough and almost no driver
> > calls trace_dma_fence_emit. But this is still more correct in theory.
>
> Well, the reason why basically no driver is calling this is because it
> is pretty much deprecated.
>
> We do have a case in the GPU scheduler where it makes sense to distinct
> between init and emit, but it doesn't really matter for drivers.
>
> So I'm not sure if it's a good idea to add that here.
visualization can't easily differentiate between drivers/timelines
where the split matters and ones where it doesn't.. IMO it is better
to just have the extra trace even in the cases where it comes at the
same time as the init trace
BR,
-R
> Regards,
> Christian.
>
> >
> > Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
> > Cc: Rob Clark <robdclark@chromium.org>
> > ---
> > drivers/gpu/drm/msm/msm_gpu.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
> > index faf0c242874e..a82193f41ea2 100644
> > --- a/drivers/gpu/drm/msm/msm_gpu.c
> > +++ b/drivers/gpu/drm/msm/msm_gpu.c
> > @@ -15,6 +15,7 @@
> > #include <linux/string_helpers.h>
> > #include <linux/devcoredump.h>
> > #include <linux/sched/task.h>
> > +#include <trace/events/dma_fence.h>
> >
> > /*
> > * Power Management:
> > @@ -769,6 +770,7 @@ void msm_gpu_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit)
> > gpu->active_submits++;
> > mutex_unlock(&gpu->active_lock);
> >
> > + trace_dma_fence_emit(submit->hw_fence);
> > gpu->funcs->submit(gpu, submit);
> > gpu->cur_ctx_seqno = submit->queue->ctx->seqno;
> >
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] drm/msm: add trace_dma_fence_emit to msm_gpu_submit
2022-04-12 19:41 ` Rob Clark
@ 2022-04-26 16:43 ` Christian König
-1 siblings, 0 replies; 12+ messages in thread
From: Christian König @ 2022-04-26 16:43 UTC (permalink / raw)
To: Rob Clark
Cc: Chia-I Wu, freedreno, dri-devel, Sean Paul, Abhinav Kumar,
David Airlie, Sumit Semwal, linux-arm-msm, Daniel Vetter
Sorry for the delayed reply.
Am 12.04.22 um 21:41 schrieb Rob Clark:
> On Sat, Apr 9, 2022 at 7:33 AM Christian König <christian.koenig@amd.com> wrote:
>> Am 08.04.22 um 23:12 schrieb Chia-I Wu:
>>> In practice, trace_dma_fence_init is good enough and almost no driver
>>> calls trace_dma_fence_emit. But this is still more correct in theory.
>> Well, the reason why basically no driver is calling this is because it
>> is pretty much deprecated.
>>
>> We do have a case in the GPU scheduler where it makes sense to distinct
>> between init and emit, but it doesn't really matter for drivers.
>>
>> So I'm not sure if it's a good idea to add that here.
> visualization can't easily differentiate between drivers/timelines
> where the split matters and ones where it doesn't.. IMO it is better
> to just have the extra trace even in the cases where it comes at the
> same time as the init trace
That's exactly the reason why I want to remove the extra trace.
To make it clear this is only useful for debugging and *NOT* for
actually visualizing things.
So by adding that here you add more confusion than solving anything.
Regards,
Christian.
>
> BR,
> -R
>
>> Regards,
>> Christian.
>>
>>> Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
>>> Cc: Rob Clark <robdclark@chromium.org>
>>> ---
>>> drivers/gpu/drm/msm/msm_gpu.c | 2 ++
>>> 1 file changed, 2 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
>>> index faf0c242874e..a82193f41ea2 100644
>>> --- a/drivers/gpu/drm/msm/msm_gpu.c
>>> +++ b/drivers/gpu/drm/msm/msm_gpu.c
>>> @@ -15,6 +15,7 @@
>>> #include <linux/string_helpers.h>
>>> #include <linux/devcoredump.h>
>>> #include <linux/sched/task.h>
>>> +#include <trace/events/dma_fence.h>
>>>
>>> /*
>>> * Power Management:
>>> @@ -769,6 +770,7 @@ void msm_gpu_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit)
>>> gpu->active_submits++;
>>> mutex_unlock(&gpu->active_lock);
>>>
>>> + trace_dma_fence_emit(submit->hw_fence);
>>> gpu->funcs->submit(gpu, submit);
>>> gpu->cur_ctx_seqno = submit->queue->ctx->seqno;
>>>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] drm/msm: add trace_dma_fence_emit to msm_gpu_submit
@ 2022-04-26 16:43 ` Christian König
0 siblings, 0 replies; 12+ messages in thread
From: Christian König @ 2022-04-26 16:43 UTC (permalink / raw)
To: Rob Clark
Cc: David Airlie, freedreno, Abhinav Kumar, dri-devel, Sumit Semwal,
linux-arm-msm, Sean Paul
Sorry for the delayed reply.
Am 12.04.22 um 21:41 schrieb Rob Clark:
> On Sat, Apr 9, 2022 at 7:33 AM Christian König <christian.koenig@amd.com> wrote:
>> Am 08.04.22 um 23:12 schrieb Chia-I Wu:
>>> In practice, trace_dma_fence_init is good enough and almost no driver
>>> calls trace_dma_fence_emit. But this is still more correct in theory.
>> Well, the reason why basically no driver is calling this is because it
>> is pretty much deprecated.
>>
>> We do have a case in the GPU scheduler where it makes sense to distinct
>> between init and emit, but it doesn't really matter for drivers.
>>
>> So I'm not sure if it's a good idea to add that here.
> visualization can't easily differentiate between drivers/timelines
> where the split matters and ones where it doesn't.. IMO it is better
> to just have the extra trace even in the cases where it comes at the
> same time as the init trace
That's exactly the reason why I want to remove the extra trace.
To make it clear this is only useful for debugging and *NOT* for
actually visualizing things.
So by adding that here you add more confusion than solving anything.
Regards,
Christian.
>
> BR,
> -R
>
>> Regards,
>> Christian.
>>
>>> Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
>>> Cc: Rob Clark <robdclark@chromium.org>
>>> ---
>>> drivers/gpu/drm/msm/msm_gpu.c | 2 ++
>>> 1 file changed, 2 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
>>> index faf0c242874e..a82193f41ea2 100644
>>> --- a/drivers/gpu/drm/msm/msm_gpu.c
>>> +++ b/drivers/gpu/drm/msm/msm_gpu.c
>>> @@ -15,6 +15,7 @@
>>> #include <linux/string_helpers.h>
>>> #include <linux/devcoredump.h>
>>> #include <linux/sched/task.h>
>>> +#include <trace/events/dma_fence.h>
>>>
>>> /*
>>> * Power Management:
>>> @@ -769,6 +770,7 @@ void msm_gpu_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit)
>>> gpu->active_submits++;
>>> mutex_unlock(&gpu->active_lock);
>>>
>>> + trace_dma_fence_emit(submit->hw_fence);
>>> gpu->funcs->submit(gpu, submit);
>>> gpu->cur_ctx_seqno = submit->queue->ctx->seqno;
>>>
^ permalink raw reply [flat|nested] 12+ messages in thread