Re: [RFC 8/8] drm/amdgpu: Convert to common fdinfo format

[Alex Deucher <alexdeucher@gmail.com>]

+ David, Roy

On Thu, Jul 15, 2021 at 5:18 AM Tvrtko Ursulin
<tvrtko.ursulin@linux.intel.com> wrote:
>
> From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
>
> Convert fdinfo format to one documented in drm-usage-stats.rst.
>
> Opens:
>  * Does it work for AMD?
>  * What are the semantics of AMD engine utilisation reported in percents?
>    Can it align with what i915 does or needs to document the alternative
>    in the specification document?
>
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> Cc: David M Nieto <David.Nieto@amd.com>
> Cc: Christian König <christian.koenig@amd.com>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> ---
>  Documentation/gpu/amdgpu.rst               | 26 ++++++++++++++++++++++
>  Documentation/gpu/drm-usage-stats.rst      |  7 +++++-
>  drivers/gpu/drm/amd/amdgpu/amdgpu_fdinfo.c | 18 ++++++++++-----
>  3 files changed, 45 insertions(+), 6 deletions(-)
>
> diff --git a/Documentation/gpu/amdgpu.rst b/Documentation/gpu/amdgpu.rst
> index 364680cdad2e..b9b79c810f28 100644
> --- a/Documentation/gpu/amdgpu.rst
> +++ b/Documentation/gpu/amdgpu.rst
> @@ -322,3 +322,29 @@ smartshift_bias
>
>  .. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
>     :doc: smartshift_bias
> +
> +.. _amdgpu-usage-stats:
> +
> +amdgpu DRM client usage stats implementation
> +============================================
> +
> +The amdgpu driver implements the DRM client usage stats specification as
> +documented in :ref:`drm-client-usage-stats`.
> +
> +Example of the output showing the implemented key value pairs and entirety of
> +the currenly possible format options:
> +
> +::
> +
> +      pos:    0
> +      flags:  0100002
> +      mnt_id: 21
> +      drm-driver: amdgpu
> +      drm-pdev:   0000:00:02.0
> +      drm-client-id:      7
> +      drm-engine-... TODO
> +      drm-memory-... TODO
> +
> +Possible `drm-engine-` key names are: ``,... TODO.
> +
> +Possible `drm-memory-` key names are: ``,... TODO.
> diff --git a/Documentation/gpu/drm-usage-stats.rst b/Documentation/gpu/drm-usage-stats.rst
> index b87505438aaa..eaaa361805c0 100644
> --- a/Documentation/gpu/drm-usage-stats.rst
> +++ b/Documentation/gpu/drm-usage-stats.rst
> @@ -69,7 +69,7 @@ scope of each device, in which case `drm-pdev` shall be present as well.
>  Userspace should make sure to not double account any usage statistics by using
>  the above described criteria in order to associate data to individual clients.
>
> -- drm-engine-<str>: <uint> ns
> +- drm-engine-<str>: <uint> [ns|%]
>
>  GPUs usually contain multiple execution engines. Each shall be given a stable
>  and unique name (str), with possible values documented in the driver specific
> @@ -84,6 +84,9 @@ larger value within a reasonable period. Upon observing a value lower than what
>  was previously read, userspace is expected to stay with that larger previous
>  value until a monotonic update is seen.
>
> +Where time unit is given as a percentage...[AMD folks to fill the semantics
> +and interpretation of that]...
> +
>  - drm-memory-<str>: <uint> [KiB|MiB]
>
>  Each possible memory type which can be used to store buffer objects by the
> @@ -101,3 +104,5 @@ Driver specific implementations
>  ===============================
>
>  :ref:`i915-usage-stats`
> +
> +:ref:`amdgpu-usage-stats`
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fdinfo.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fdinfo.c
> index d94c5419ec25..d6b011008fe9 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fdinfo.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fdinfo.c
> @@ -76,11 +76,19 @@ void amdgpu_show_fdinfo(struct seq_file *m, struct file *f)
>         }
>         amdgpu_vm_get_memory(&fpriv->vm, &vram_mem, &gtt_mem, &cpu_mem);
>         amdgpu_bo_unreserve(fpriv->vm.root.bo);
> -       seq_printf(m, "pdev:\t%04x:%02x:%02x.%d\npasid:\t%u\n", domain, bus,
> +
> +       /*
> +        * ******************************************************************
> +        * For text output format description please see drm-usage-stats.rst!
> +        * ******************************************************************
> +        */
> +
> +       seq_puts(m, "drm-driver: amdgpu\n");
> +       seq_printf(m, "drm-pdev:\t%04x:%02x:%02x.%d\npasid:\t%u\n", domain, bus,
>                         dev, fn, fpriv->vm.pasid);
> -       seq_printf(m, "vram mem:\t%llu kB\n", vram_mem/1024UL);
> -       seq_printf(m, "gtt mem:\t%llu kB\n", gtt_mem/1024UL);
> -       seq_printf(m, "cpu mem:\t%llu kB\n", cpu_mem/1024UL);
> +       seq_printf(m, "drm-memory-vram:\t%llu KiB\n", vram_mem/1024UL);
> +       seq_printf(m, "drm-memory-gtt:\t%llu KiB\n", gtt_mem/1024UL);
> +       seq_printf(m, "drm-memory-cpu:\t%llu KiB\n", cpu_mem/1024UL);
>         for (i = 0; i < AMDGPU_HW_IP_NUM; i++) {
>                 uint32_t count = amdgpu_ctx_num_entities[i];
>                 int idx = 0;
> @@ -96,7 +104,7 @@ void amdgpu_show_fdinfo(struct seq_file *m, struct file *f)
>                         perc = div64_u64(10000 * total, min);
>                         frac = perc % 100;
>
> -                       seq_printf(m, "%s%d:\t%d.%d%%\n",
> +                       seq_printf(m, "drm-engine-%s%d:\t%d.%d %%\n",
>                                         amdgpu_ip_name[i],
>                                         idx, perc/100, frac);
>                 }
> --
> 2.30.2
>