Re: [PATCH v8 0/5] Add fdinfo support to Panfrost

[Boris Brezillon]

On Fri, 29 Sep 2023 19:14:26 +0100
Adrián Larumbe <adrian.larumbe@xxxxxxxxxxxxx> wrote:

> This patch series adds fdinfo support to the Panfrost DRM driver. It will
> display a series of key:value pairs under /proc/pid/fdinfo/fd for render
> processes that open the Panfrost DRM file.
> 
> The pairs contain basic drm gpu engine and memory region information that
> can either be cat by a privileged user or accessed with IGT's gputop
> utility.
> 
> Changelog:
> 
> v1: https://lore.kernel.org/lkml/bb52b872-e41b-3894-285e-b52cfc849782@xxxxxxx/T/
> 
> v2: https://lore.kernel.org/lkml/20230901084457.5bc1ad69@xxxxxxxxxxxxx/T/
>  - Changed the way gpu cycles and engine time are calculated, using GPU
>    registers and taking into account potential resets.
>  - Split render engine values into fragment and vertex/tiler ones.
>  - Added more fine-grained calculation of RSS size for BO's.
>  - Implemente selection of drm-memory region size units.
>  - Removed locking of shrinker's mutex in GEM obj status function.
> 
> v3: https://lore.kernel.org/lkml/20230905184533.959171-1-adrian.larumbe@xxxxxxxxxxxxx/
>  - Changed fdinfo engine names to something more descriptive.;
>  - Mentioned GPU cycle counts aren't an exact measure.
>  - Handled the case when job->priv might be NULL.
>  - Handled 32 bit overflow of cycle register.
>  - Kept fdinfo drm memory stats size unit display within 10k times the
>    previous multiplier for more accurate BO size numbers.
>  - Removed special handling of Prime imported BO RSS.
>  - Use rss_size only for heap objects.
>  - Use bo->base.madv instead of specific purgeable flag.
>  - Fixed kernel test robot warnings.
> 
> v4: https://lore.kernel.org/lkml/20230912084044.955864-1-adrian.larumbe@xxxxxxxxxxxxx/
>  - Move cycle counter get and put to panfrost_job_hw_submit and
>    panfrost_job_handle_{err,done} for more accuracy.
>  - Make sure cycle counter refs are released in reset path
>  - Drop the model param for toggling cycle counting and do
>    leave it down to the debugfs file.
>  - Don't disable cycle counter when togglint debugfs file,
>    let refcounting logic handle it instead.
>  - Remove fdinfo data nested structure definion and 'names' field
>  - When incrementing BO RSS size in GPU MMU page fault IRQ handler, assume
>    granuality of 2MiB for every successful mapping.
>  - drm-file picks an fdinfo memory object size unit that doesn't lose precision.
> 
> v5: https://lore.kernel.org/lkml/20230914223928.2374933-1-adrian.larumbe@xxxxxxxxxxxxx/
>  - Removed explicit initialisation of atomic variable for profiling mode,
>    as it's allocated with kzalloc.
>  - Pass engine utilisation structure to jobs rather than the file context, to avoid
>    future misusage of the latter.
>  - Remove double reading of cycle counter register and ktime in job deqeueue function,
>    as the scheduler will make sure these values are read over in case of requeuing.
>  - Moved putting of cycle counting refcnt into panfrost job dequeue.
>    function to avoid repetition.
> 
> v6: https://lore.kernel.org/lkml/c73ad42b-a8db-23c2-86c7-1a2939dba044@xxxxxxxxxxxxxxx/T/
>  - Fix wrong swapped-round engine time and cycle values in fdinfo
>    drm print statements.
> 
> v7: https://lore.kernel.org/lkml/20230927213133.1651169-6-adrian.larumbe@xxxxxxxxxxxxx/T/
>  - Make sure an object's actual RSS size is added to the overall fdinfo's purgeable
>    and active size tally when it's both resident and purgeable or active.
>  - Create a drm/panfrost.rst documentation file with meaning of fdinfo strings.
>  - BUILD_BUG_ON checking the engine name array size for fdinfo.
>  - Added copyright notices for Amazon in Panfrost's new debugfs files.
>  - Discarded fdinfo memory stats unit size selection patch.
> 
> v8:
>  - Style improvements and addressing nitpicks.         
> 
> Adrián Larumbe (5):
>   drm/panfrost: Add cycle count GPU register definitions
>   drm/panfrost: Add fdinfo support GPU load metrics
>   drm/panfrost: Add fdinfo support for memory stats
>   drm/drm_file: Add DRM obj's RSS reporting function for fdinfo
>   drm/panfrost: Implement generic DRM object RSS reporting function

Queued to drm-misc-next.

Thanks!

Boris

> 
>  Documentation/gpu/drm-usage-stats.rst       |  1 +
>  Documentation/gpu/panfrost.rst              | 38 +++++++++++++
>  drivers/gpu/drm/drm_file.c                  |  8 +--
>  drivers/gpu/drm/panfrost/Makefile           |  2 +
>  drivers/gpu/drm/panfrost/panfrost_debugfs.c | 21 ++++++++
>  drivers/gpu/drm/panfrost/panfrost_debugfs.h | 14 +++++
>  drivers/gpu/drm/panfrost/panfrost_devfreq.c |  8 +++
>  drivers/gpu/drm/panfrost/panfrost_devfreq.h |  3 ++
>  drivers/gpu/drm/panfrost/panfrost_device.c  |  2 +
>  drivers/gpu/drm/panfrost/panfrost_device.h  | 13 +++++
>  drivers/gpu/drm/panfrost/panfrost_drv.c     | 60 ++++++++++++++++++++-
>  drivers/gpu/drm/panfrost/panfrost_gem.c     | 30 +++++++++++
>  drivers/gpu/drm/panfrost/panfrost_gem.h     |  5 ++
>  drivers/gpu/drm/panfrost/panfrost_gpu.c     | 41 ++++++++++++++
>  drivers/gpu/drm/panfrost/panfrost_gpu.h     |  4 ++
>  drivers/gpu/drm/panfrost/panfrost_job.c     | 24 +++++++++
>  drivers/gpu/drm/panfrost/panfrost_job.h     |  5 ++
>  drivers/gpu/drm/panfrost/panfrost_mmu.c     |  1 +
>  drivers/gpu/drm/panfrost/panfrost_regs.h    |  5 ++
>  include/drm/drm_gem.h                       |  9 ++++
>  20 files changed, 290 insertions(+), 4 deletions(-)
>  create mode 100644 Documentation/gpu/panfrost.rst
>  create mode 100644 drivers/gpu/drm/panfrost/panfrost_debugfs.c
>  create mode 100644 drivers/gpu/drm/panfrost/panfrost_debugfs.h
> 
> 
> base-commit: f45acf7acf75921c0409d452f0165f51a19a74fd