Print the accumulated runtime for client when printing fdinfo.
Each time a query is done it first does 2 things:
1) loop through all the exec queues for the current client and
accumulate the runtime, per engine class. CTX_TIMESTAMP is used for
that, being read from the context image.
2) Read a "GPU timestamp" that can be used for considering "how much GPU
time has passed" and that has the same unit/refclock as the one
recording the runtime. RING_TIMESTAMP is used for that via MMIO.
Since for all current platforms RING_TIMESTAMP follows the same
refclock, just read it once, using any first engine available.
This is exported to userspace as 2 numbers in fdinfo:
drm-cycles-<class>: <RUNTIME>
drm-total-cycles-<class>: <TIMESTAMP>
Userspace is expected to collect at least 2 samples, which allows to
know the client engine busyness as per:
RUNTIME1 - RUNTIME0
busyness = ---------------------
T1 - T0
Since drm-cycles-<class> always starts at 0, it's also possible to know
if and engine was ever used by a client.
It's expected that userspace will read any 2 samples every few seconds.
Given the update frequency of the counters involved and that
CTX_TIMESTAMP is 32-bits, the counter for each exec_queue can wrap
around (assuming 100% utilization) after ~200s. The wraparound is not
perceived by userspace since it's just accumulated for all the
exec_queues in a 64-bit counter) but the measurement will not be
accurate if the samples are too far apart.
This could be mitigated by adding a workqueue to accumulate the counters
every so often, but it's additional complexity for something that is
done already by userspace every few seconds in tools like gputop (from
igt), htop, nvtop, etc, with none of them really defaulting to 1 sample
per minute or more.
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Acked-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240517204310.88854-9-lucas.demarchi@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Clarify the documentation in preparation for updated
helpers which check the handle count as well as whether
a dma-buf has been attached.
Link: https://lore.kernel.org/all/20231207180225.439482-1-alexander.deucher@amd.com/
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.keonig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
The drm-stats fdinfo tags made available to user space are drm-engine,
drm-cycles, drm-max-freq and drm-curfreq, one per job slot.
This deviates from standard practice in other DRM drivers, where a single
set of key:value pairs is provided for the whole render engine. However,
Panfrost has separate queues for fragment and vertex/tiler jobs, so a
decision was made to calculate bus cycles and workload times separately.
Maximum operating frequency is calculated at devfreq initialisation time.
Current frequency is made available to user space because nvtop uses it
when performing engine usage calculations.
It is important to bear in mind that both GPU cycle and kernel time numbers
provided are at best rough estimations, and always reported in excess from
the actual figure because of two reasons:
- Excess time because of the delay between the end of a job processing,
the subsequent job IRQ and the actual time of the sample.
- Time spent in the engine queue waiting for the GPU to pick up the next
job.
To avoid race conditions during enablement/disabling, a reference counting
mechanism was introduced, and a job flag that tells us whether a given job
increased the refcount. This is necessary, because user space can toggle
cycle counting through a debugfs file, and a given job might have been in
flight by the time cycle counting was disabled.
The main goal of the debugfs cycle counter knob is letting tools like nvtop
or IGT's gputop switch it at any time, to avoid power waste in case no
engine usage measuring is necessary.
Also add a documentation file explaining the possible values for fdinfo's
engine keystrings and Panfrost-specific drm-curfreq-<keystr> pairs.
Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230929181616.2769345-3-adrian.larumbe@collabora.com
The restriction about no whitespace, etc, really only applies to the
usage of strings in keys. Values can contain anything (other than
newline).
Signed-off-by: Rob Clark <robdclark@chromium.org>
Acked-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230524155956.382440-8-robdclark@gmail.com
Add support to dump GEM stats to fdinfo.
v2: Fix typos, change size units to match docs, use div_u64
v3: Do it in core
v4: more kerneldoc
v5: doc fixes
v6: Actually use u64, bit more comment docs
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230524155956.382440-6-robdclark@gmail.com
Handle a bit of the boiler-plate in a single case, and make it easier to
add some core tracked stats. This also ensures consistent behavior
across drivers for standardised fields.
v2: Update drm-usage-stats.rst, 64b client-id, rename drm_show_fdinfo
v3: Rebase on drm-misc-next
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Acked-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230524155956.382440-3-robdclark@gmail.com
Similar to AMD commit
8744425411 ("drm/amdgpu: Add show_fdinfo() interface"), using the
infrastructure added in previous patches, we add basic client info
and GPU engine utilisation for i915.
Example of the output:
pos: 0
flags: 0100002
mnt_id: 21
drm-driver: i915
drm-pdev: 0000:00:02.0
drm-client-id: 7
drm-engine-render: 9288864723 ns
drm-engine-copy: 2035071108 ns
drm-engine-video: 0 ns
drm-engine-video-enhance: 0 ns
v2:
* Update for removal of name and pid.
v3:
* Use drm_driver.name.
v4:
* Added drm-engine-capacity- tag.
* Fix typo. (Umesh)
v5:
* Don't output engine data before Gen8.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: David M Nieto <David.Nieto@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Chris Healy <cphealy@gmail.com>
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Acked-by: Rob Clark <robdclark@gmail.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220401142205.3123159-9-tvrtko.ursulin@linux.intel.com
Proposal to standardise the fdinfo text format as optionally output by DRM
drivers.
Idea is that a simple but, well defined, spec will enable generic
userspace tools to be written while at the same time avoiding a more heavy
handed approach of adding a mid-layer to DRM.
i915 implements a subset of the spec, everything apart from the memory
stats currently, and a matching intel_gpu_top tool exists.
Open is to see if AMD can migrate to using the proposed GPU utilisation
key-value pairs, or if they are not workable to see whether to go
vendor specific, or if a standardised alternative can be found which is
workable for both drivers.
Same for the memory utilisation key-value pairs proposal.
v2:
* Update for removal of name and pid.
v3:
* 'Drm-driver' tag will be obtained from struct drm_driver.name. (Daniel)
v4:
* Added drm-engine-capacity- tag.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: David M Nieto <David.Nieto@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Daniel Stone <daniel@fooishbar.org>
Cc: Chris Healy <cphealy@gmail.com>
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220401142205.3123159-7-tvrtko.ursulin@linux.intel.com
