Re: [PATCH v8 0/5] Support fdinfo runtime and memory stats on Panthor

[Boris Brezillon <boris.brezillon@collabora.com>]

On Tue, 24 Sep 2024 00:06:20 +0100
Adrián Larumbe <adrian.larumbe@collabora.com> wrote:

> This patch series enables userspace utilities like gputop and nvtop to query a
> render context's fdinfo file and figure out rates of engine and memory utilisation.
> 
> Previous discussion can be found at
> https://lore.kernel.org/dri-devel/20240920234436.207563-1-adrian.larumbe@collabora.com/
> 
> Changelog:
> v8:
>  - Fixed uninitialised stack variable bug that was triggering an invalid memory reference.
>  - Added a few R-b tags to commits
> v7:
>  - Fixed some kernel test bot-reported documentation and sign mismatch errors.
>  - Defined convenience macros for specifying CS instructions according to their profiled status.
>  - Explicitly initialised instruction count for structure containing a job's
>  instructions when calculating its amount of credits for the scheduler.
>  - Some minor cosmetic nits. 
> v6:
>  - Addressed some nits and style issues.
>  - Enforced static assert equality of instruction buffer when calculating job
>  credits or copying them into the ringbuffer.
>  - Added explanation to the way in which job credits and profiled job size is done.
>  - Broke down fdinfo enablement patch into two, one of them dealing with adding
>  support for calculating the current and top operating device frequencies
>  - Fixed race at the time drm file-wide profiling stats are gathered from groups.
> v5:
>  - Moved profiling information slots into a per-queue BO and away from syncobjs.
>  - Decide on size of profiling slots BO from size of CS for minimal profiled job
>  - Turn job and device profiling flag into a bit mask so that individual metrics
>  can be enabled separately.
>  - Shrunk ringbuffer slot size to that of a cache line.
>  - Track profiling slot indeces separately from the job's queue ringbuffer's
>  - Emit CS instructions one by one and tag them depending on profiling mask
>  - New helper for calculating job credits depending on profiling flags
>  - Add Documentation file for sysfs profiling knob
>  - fdinfo will only show engines or cycles tags if these are respectively enabled.
> v4:
>  - Fixed wrong assignment location for frequency values in Panthor's devfreq
>  - Removed the last two commits about registering size of internal BO's
>  - Rearranged patch series so that sysfs knob is done last and all the previous
>  time sampling and fdinfo show dependencies are already in place
> v3:
>  - Fixed some nits and removed useless bounds check in panthor_sched.c
>  - Added support for sysfs profiling knob and optional job accounting
>  - Added new patches for calculating size of internal BO's
> v2:
>  - Split original first patch in two, one for FW CS cycle and timestamp
>  calculations and job accounting memory management, and a second one
>  that enables fdinfo.
>  - Moved NUM_INSTRS_PER_SLOT to the file prelude
>  - Removed nelem variable from the group's struct definition.
>  - Precompute size of group's syncobj BO to avoid code duplication.
>  - Some minor nits.
> 
> Adrián Larumbe (5):
>   drm/panthor: introduce job cycle and timestamp accounting
>   drm/panthor: record current and maximum device clock frequencies
>   drm/panthor: add DRM fdinfo support
>   drm/panthor: enable fdinfo for memory stats
>   drm/panthor: add sysfs knob for enabling job profiling

Queued to drm-misc-next after applying the few modifications I
mentioned. Also added Steve's ack (given on IRC) on the first patch.

> 
>  .../testing/sysfs-driver-panthor-profiling    |  10 +
>  Documentation/gpu/panthor.rst                 |  46 +++
>  drivers/gpu/drm/panthor/panthor_devfreq.c     |  18 +-
>  drivers/gpu/drm/panthor/panthor_device.h      |  36 ++
>  drivers/gpu/drm/panthor/panthor_drv.c         |  73 ++++
>  drivers/gpu/drm/panthor/panthor_gem.c         |  12 +
>  drivers/gpu/drm/panthor/panthor_sched.c       | 384 +++++++++++++++---
>  drivers/gpu/drm/panthor/panthor_sched.h       |   2 +
>  8 files changed, 531 insertions(+), 50 deletions(-)
>  create mode 100644 Documentation/ABI/testing/sysfs-driver-panthor-profiling
>  create mode 100644 Documentation/gpu/panthor.rst
>