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

Boris Brezillon
2024-10-02T08:57:23Z

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
>