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

Adrián Larumbe
2024-09-23T23:09:40Z

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

.../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

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2.46.0