[PATCH v4] Add power/gpu_frequency tracepoint.

[Peiyong Lin]

On Tue, Nov 17, 2020 at 1:31 PM Peiyong Lin <lpy at google.com> wrote:
>
> On Thu, Oct 22, 2020 at 10:34 AM Peiyong Lin <lpy at google.com> wrote:
> >
> > Historically there is no common trace event for GPU frequency, in
> > downstream Android each different hardware vendor implements their own
> > way to expose GPU frequency, for example as a debugfs node.  This patch
> > standardize it as a common trace event in upstream linux kernel to help
> > the ecosystem have a common implementation across hardware vendors.
> > Toolings in the Linux ecosystem will benefit from this especially in the
> > downstream Android, where this information is critical to graphics
> > developers.
> >
> > Signed-off-by: Peiyong Lin <lpy at google.com>
> > ---
> >
> > Changelog since v3:
> >  - Correct copyright title.
> >
> > Changelog since v2:
> >  - Add more comments to indicate when the event should be emitted.
> >  - Change state to frequency.
> >
> > Changelog since v1:
> >  - Use %u in TP_printk
> >
> >  drivers/gpu/Makefile                    |  1 +
> >  drivers/gpu/trace/Kconfig               |  3 +++
> >  drivers/gpu/trace/Makefile              |  1 +
> >  drivers/gpu/trace/trace_gpu_frequency.c | 13 ++++++++++
> >  include/trace/events/power.h            | 33 +++++++++++++++++++++++++
> >  5 files changed, 51 insertions(+)
> >  create mode 100644 drivers/gpu/trace/trace_gpu_frequency.c
> >
> > diff --git a/drivers/gpu/Makefile b/drivers/gpu/Makefile
> > index 835c88318cec..f289a47eb031 100644
> > --- a/drivers/gpu/Makefile
> > +++ b/drivers/gpu/Makefile
> > @@ -6,3 +6,4 @@ obj-$(CONFIG_TEGRA_HOST1X)      += host1x/
> >  obj-y                  += drm/ vga/
> >  obj-$(CONFIG_IMX_IPUV3_CORE)   += ipu-v3/
> >  obj-$(CONFIG_TRACE_GPU_MEM)            += trace/
> > +obj-$(CONFIG_TRACE_GPU_FREQUENCY)              += trace/
> > diff --git a/drivers/gpu/trace/Kconfig b/drivers/gpu/trace/Kconfig
> > index c24e9edd022e..ac4aec8d5845 100644
> > --- a/drivers/gpu/trace/Kconfig
> > +++ b/drivers/gpu/trace/Kconfig
> > @@ -2,3 +2,6 @@
> >
> >  config TRACE_GPU_MEM
> >         bool
> > +
> > +config TRACE_GPU_FREQUENCY
> > +       bool
> > diff --git a/drivers/gpu/trace/Makefile b/drivers/gpu/trace/Makefile
> > index b70fbdc5847f..2b7ae69327d6 100644
> > --- a/drivers/gpu/trace/Makefile
> > +++ b/drivers/gpu/trace/Makefile
> > @@ -1,3 +1,4 @@
> >  # SPDX-License-Identifier: GPL-2.0
> >
> >  obj-$(CONFIG_TRACE_GPU_MEM) += trace_gpu_mem.o
> > +obj-$(CONFIG_TRACE_GPU_FREQUENCY) += trace_gpu_frequency.o
> > diff --git a/drivers/gpu/trace/trace_gpu_frequency.c b/drivers/gpu/trace/trace_gpu_frequency.c
> > new file mode 100644
> > index 000000000000..668fabd6b77a
> > --- /dev/null
> > +++ b/drivers/gpu/trace/trace_gpu_frequency.c
> > @@ -0,0 +1,13 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * GPU frequency trace points
> > + *
> > + * Copyright (C) 2020 Google LLC
> > + */
> > +
> > +#include <linux/module.h>
> > +
> > +#define CREATE_TRACE_POINTS
> > +#include <trace/events/power.h>
> > +
> > +EXPORT_TRACEPOINT_SYMBOL(gpu_frequency);
> > diff --git a/include/trace/events/power.h b/include/trace/events/power.h
> > index af5018aa9517..343825a76953 100644
> > --- a/include/trace/events/power.h
> > +++ b/include/trace/events/power.h
> > @@ -500,6 +500,39 @@ DEFINE_EVENT(dev_pm_qos_request, dev_pm_qos_remove_request,
> >
> >         TP_ARGS(name, type, new_value)
> >  );
> > +
> > +/**
> > + * gpu_frequency - Reports the GPU frequency in GPU clock domains.
> > + *
> > + * This event should be emitted whenever there's a GPU frequency change happens,
> > + * or a GPU goes from idle state to active state, or vice versa.
> > + *
> > + * When the GPU goes from idle state to active state, this event should report
> > + * the GPU frequency of the active state. When the GPU goes from active state to
> > + * idle state, this event should report a zero frequency value.
> > + *
> > + * @frequency:  New frequency (in KHz)
> > + * @gpu_id: Id for each GPU clock domain
> > + */
> > +TRACE_EVENT(gpu_frequency,
> > +
> > +       TP_PROTO(unsigned int frequency, unsigned int gpu_id),
> > +
> > +       TP_ARGS(frequency, gpu_id),
> > +
> > +       TP_STRUCT__entry(
> > +               __field(unsigned int, frequency)
> > +               __field(unsigned int, gpu_id)
> > +       ),
> > +
> > +       TP_fast_assign(
> > +               __entry->frequency = frequency;
> > +               __entry->gpu_id = gpu_id;
> > +       ),
> > +
> > +       TP_printk("frequency=%u gpu_id=%u",
> > +               __entry->frequency, __entry->gpu_id)
> > +);
> >  #endif /* _TRACE_POWER_H */
> >
> >  /* This part must be outside protection */
> > --
> > 2.29.0.rc1.297.gfa9743e501-goog
> >
>
>
> Hi there,
>
> Per request, re-send this patch with dri-devel@ list CCed.
>
> Thanks,
> Peiyong

Hi there,

For GPU drivers folks in dri-devel@ list, any input?

Thanks,
Peiyong