[RFC 3/6] drm: Add fdinfo memory stats

[Rob Clark]

On Mon, Apr 17, 2023 at 8:56 AM Tvrtko Ursulin
<tvrtko.ursulin at linux.intel.com> wrote:
>
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
>
> Add support to dump GEM stats to fdinfo.
>
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> ---
>  Documentation/gpu/drm-usage-stats.rst | 12 +++++++
>  drivers/gpu/drm/drm_file.c            | 52 +++++++++++++++++++++++++++
>  include/drm/drm_drv.h                 |  7 ++++
>  include/drm/drm_file.h                |  8 +++++
>  4 files changed, 79 insertions(+)
>
> diff --git a/Documentation/gpu/drm-usage-stats.rst b/Documentation/gpu/drm-usage-stats.rst
> index 2ab32c40e93c..8273a41b2fb0 100644
> --- a/Documentation/gpu/drm-usage-stats.rst
> +++ b/Documentation/gpu/drm-usage-stats.rst
> @@ -21,6 +21,7 @@ File format specification
>
>  - File shall contain one key value pair per one line of text.
>  - Colon character (`:`) must be used to delimit keys and values.
> +- Caret (`^`) is also a reserved character.

this doesn't solve the problem that led me to drm-$CATEGORY-memory... ;-)

(also, it is IMHO rather ugly)

BR,
-R

>  - All keys shall be prefixed with `drm-`.
>  - Whitespace between the delimiter and first non-whitespace character shall be
>    ignored when parsing.
> @@ -105,6 +106,17 @@ object belong to this client, in the respective memory region.
>  Default unit shall be bytes with optional unit specifiers of 'KiB' or 'MiB'
>  indicating kibi- or mebi-bytes.
>
> +- drm-memory-<str>^size:      <uint> [KiB|MiB]
> +- drm-memory-<str>^shared:    <uint> [KiB|MiB]
> +- drm-memory-<str>^resident:  <uint> [KiB|MiB]
> +- drm-memory-<str>^purgeable: <uint> [KiB|MiB]
> +- drm-memory-<str>^active:    <uint> [KiB|MiB]
> +
> +Resident category is identical to the drm-memory-<str> key and two should be
> +mutually exclusive.
> +
> +TODO more description text...
> +
>  - drm-cycles-<str> <uint>
>
>  Engine identifier string must be the same as the one specified in the
> diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
> index 37b4f76a5191..e202f79e816d 100644
> --- a/drivers/gpu/drm/drm_file.c
> +++ b/drivers/gpu/drm/drm_file.c
> @@ -42,6 +42,7 @@
>  #include <drm/drm_client.h>
>  #include <drm/drm_drv.h>
>  #include <drm/drm_file.h>
> +#include <drm/drm_gem.h>
>  #include <drm/drm_print.h>
>
>  #include "drm_crtc_internal.h"
> @@ -871,6 +872,54 @@ void drm_send_event(struct drm_device *dev, struct drm_pending_event *e)
>  }
>  EXPORT_SYMBOL(drm_send_event);
>
> +static void
> +print_stat(struct drm_printer *p, const char *stat, const char *region, u64 sz)
> +{
> +       const char *units[] = {"", " KiB", " MiB"};
> +       unsigned int u;
> +
> +       if (sz == ~0ull) /* Not supported by the driver. */
> +               return;
> +
> +       for (u = 0; u < ARRAY_SIZE(units) - 1; u++) {
> +               if (sz < SZ_1K)
> +                       break;
> +               sz = div_u64(sz, SZ_1K);
> +       }
> +
> +       drm_printf(p, "drm-memory-%s^%s:\t%llu%s\n",
> +                  region, stat, sz, units[u]);
> +}
> +
> +static void print_memory_stats(struct drm_printer *p, struct drm_file *file)
> +{
> +       struct drm_device *dev = file->minor->dev;
> +       struct drm_fdinfo_memory_stat *stats;
> +       unsigned int num, i;
> +       char **regions;
> +
> +       regions = dev->driver->query_fdinfo_memory_regions(dev, &num);
> +
> +       stats = kcalloc(num, sizeof(*stats), GFP_KERNEL);
> +       if (!stats)
> +               return;
> +
> +       dev->driver->query_fdinfo_memory_stats(file, stats);
> +
> +       for (i = 0; i < num; i++) {
> +               if (!regions[i]) /* Allow sparse name arrays. */
> +                       continue;
> +
> +               print_stat(p, "size", regions[i], stats[i].size);
> +               print_stat(p, "shared", regions[i], stats[i].shared);
> +               print_stat(p, "resident", regions[i], stats[i].resident);
> +               print_stat(p, "purgeable", regions[i], stats[i].purgeable);
> +               print_stat(p, "active", regions[i], stats[i].active);
> +       }
> +
> +       kfree(stats);
> +}
> +
>  /**
>   * drm_show_fdinfo - helper for drm file fops
>   * @seq_file: output stream
> @@ -900,6 +949,9 @@ void drm_show_fdinfo(struct seq_file *m, struct file *f)
>
>         if (dev->driver->show_fdinfo)
>                 dev->driver->show_fdinfo(&p, file);
> +
> +       if (dev->driver->query_fdinfo_memory_regions)
> +               print_memory_stats(&p, file);
>  }
>  EXPORT_SYMBOL(drm_show_fdinfo);
>
> diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
> index 89e2706cac56..ccc1cd98d2aa 100644
> --- a/include/drm/drm_drv.h
> +++ b/include/drm/drm_drv.h
> @@ -35,6 +35,7 @@
>  #include <drm/drm_device.h>
>
>  struct drm_file;
> +struct drm_fdinfo_memory_stat;
>  struct drm_gem_object;
>  struct drm_master;
>  struct drm_minor;
> @@ -408,6 +409,12 @@ struct drm_driver {
>          */
>         void (*show_fdinfo)(struct drm_printer *p, struct drm_file *f);
>
> +       char ** (*query_fdinfo_memory_regions)(struct drm_device *dev,
> +                                              unsigned int *num);
> +
> +       void (*query_fdinfo_memory_stats)(struct drm_file *f,
> +                                         struct drm_fdinfo_memory_stat *stat);
> +
>         /** @major: driver major number */
>         int major;
>         /** @minor: driver minor number */
> diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
> index 7d9b3c65cbc1..00d48beeac5c 100644
> --- a/include/drm/drm_file.h
> +++ b/include/drm/drm_file.h
> @@ -375,6 +375,14 @@ struct drm_file {
>  #endif
>  };
>
> +struct drm_fdinfo_memory_stat {
> +       u64 size;
> +       u64 shared;
> +       u64 resident;
> +       u64 purgeable;
> +       u64 active;
> +};
> +
>  /**
>   * drm_is_primary_client - is this an open file of the primary node
>   * @file_priv: DRM file
> --
> 2.37.2
>