On Tue, Aug 13, 2024 at 6:57 AM Tvrtko Ursulin <tursulin@xxxxxxxxxx> wrote: > > From: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxx> > > Currently it is not well defined what is drm-memory- compared to other > categories. > > In practice the only driver which emits these keys is amdgpu and in them > exposes the current resident buffer object memory (including shared). > > To prevent any confusion, document that drm-memory- is deprecated and an > alias for drm-resident-memory-. > > While at it also clarify that the reserved sub-string 'memory' refers to > the memory region component, and also clarify the intended semantics of > other memory categories. > > v2: > * Also mark drm-memory- as deprecated. > * Add some more text describing memory categories. (Alex) > > v3: > * Semantics of the amdgpu drm-memory is actually as drm-resident. > > Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxx> > Cc: Alex Deucher <alexander.deucher@xxxxxxx> > Cc: Christian König <christian.keonig@xxxxxxx> > Cc: Rob Clark <robdclark@xxxxxxxxxxxx> Reviewed-by: Rob Clark <robdclark@xxxxxxxxx> > --- > Documentation/gpu/drm-usage-stats.rst | 25 ++++++++++++++++++++++--- > 1 file changed, 22 insertions(+), 3 deletions(-) > > diff --git a/Documentation/gpu/drm-usage-stats.rst b/Documentation/gpu/drm-usage-stats.rst > index a80f95ca1b2f..ff964c707754 100644 > --- a/Documentation/gpu/drm-usage-stats.rst > +++ b/Documentation/gpu/drm-usage-stats.rst > @@ -144,7 +144,9 @@ Memory > > Each possible memory type which can be used to store buffer objects by the > GPU in question shall be given a stable and unique name to be returned as the > -string here. The name "memory" is reserved to refer to normal system memory. > +string here. > + > +The region name "memory" is reserved to refer to normal system memory. > > Value shall reflect the amount of storage currently consumed by the buffer > objects belong to this client, in the respective memory region. > @@ -152,6 +154,9 @@ objects 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. > > +This key is deprecated and is an alias for drm-resident-<region>. Only one of > +the two should be present in the output. > + > - drm-shared-<region>: <uint> [KiB|MiB] > > The total size of buffers that are shared with another file (e.g., have more > @@ -159,20 +164,34 @@ than a single handle). > > - drm-total-<region>: <uint> [KiB|MiB] > > -The total size of buffers that including shared and private memory. > +The total size of all created buffers including shared and private memory. The > +backing store for the buffers does not have to be currently instantiated to be > +counted under this category. > > - drm-resident-<region>: <uint> [KiB|MiB] > > -The total size of buffers that are resident in the specified region. > +The total size of buffers that are resident (have their backing store present or > +instantiated) in the specified region. > + > +This is an alias for drm-memory-<region> and only one of the two should be > +present in the output. > > - drm-purgeable-<region>: <uint> [KiB|MiB] > > The total size of buffers that are purgeable. > > +For example drivers which implement a form of 'madvise' like functionality can > +here count buffers which have instantiated backing store, but have been marked > +with an equivalent of MADV_DONTNEED. > + > - drm-active-<region>: <uint> [KiB|MiB] > > The total size of buffers that are active on one or more engines. > > +One practical example of this can be presence of unsignaled fences in an GEM > +buffer reservation object. Therefore the active category is a subset of > +resident. > + > Implementation Details > ====================== > > -- > 2.44.0 >
