Add explicit validation for plot-axis values so string/type axes fail with a
clear CLI error instead of a raw float conversion exception. Add regression
coverage for a type axis.
Route NVBench JSON read failures and missing required root keys through the
documented user-facing error path so malformed inputs return 1 instead of
producing a traceback.
Allow deterministic mean-based timing summaries with zero standard deviation to
form zero-width intervals, while still rejecting negative or non-finite
dispersion values. Reuse the same non-negative finite predicate for relative
noise validation.
Add regression coverage for unreadable inputs, missing root keys, and identical
stable timing summaries.
Let argparse derive the program name from the actual invocation instead of
hardcoding nvbench_compare, so help and error output match the installed
nvbench-compare entry point.
Declare comparison inputs as explicit positional arguments and use parse_args()
instead of parse_known_args(). This preserves --dump-config without input files
while rejecting unknown options through argparse rather than treating typoed
flags as JSON paths.
Add regression coverage for rejecting an unknown CLI option.
Skip UNKNOWN rows when collecting summary plot entries so non-numeric
fractional differences cannot reach the plotting path. Add a regression test
that exercises compare_benches(..., plot=True) with an UNKNOWN row.
Document the supported pow2 axis-filter syntax and update the CLI help example
to use NAME[pow2]=EXP, matching the parser behavior for axes displayed as 2^N.
* Document when status ???? (UNKNOWN) is emitted
* Clarify --no-color behavior
* nvbench_compare.md: clarify --no-color behavior, fix example
* Document display options in nvbench_compare.md
* Small mention of plotting capabilities in nvbench_compare.md
* Call out that example requires shell with process substitution capabilities
Test file changed to use get_default_thresholds() function instead
of call to constructor.
This is to make sure that default preset values do not diverge from
values encoded in the constructor.
* Define nan and inf in generated --bulk-debug-python scripts so pprint output
for non-finite timing values remains valid Python code. Add a regression test
that executes the generated script and verifies nan/inf values round-trip.
* Sharpen bulk-cycle confirmation gating. Only suppress summary-clock
fallback when both reference and compare inputs provide paired, non-empty bulk
sample/frequency payloads. Missing or empty bulk files are treated as
unavailable evidence and still allow sm_clock_rate/mean fallback, while
malformed non-empty payloads continue to produce AMBG.
Add regression coverage for missing bulk files falling back to summary-cycle
confirmation.
These changes resolve automated review feedback
* Register the dynamically loaded nvbench_compare module in sys.modules before
executing it so tests better match normal import behavior.
* Add shared tabulate-capture helpers and select rendered comparison tables by
header suffix instead of relying on the last tabulate call. This makes display
tests robust to future summary or legend table output.
* Add coverage for unusable bulk cycle data forcing an ambiguous result instead
of falling back to summary clock confirmation.
* Rename the TOML parser integration test to clarify that it exercises whichever
parser is available in the environment, and document the Python 3.10 tomli
skip behavior.
When bulk sample or frequency sources are present, do not silently fall
back to summary SM clock confirmation if the bulk cycle data cannot be
used. Report the clear-gap decision as AMBG with a
bulk_cycle_data_unusable reason instead.
Still allow summary-clock fallback when no bulk sample/frequency sources
are present.
Also update the Unknown summary label to describe the broader set of
input-data failures now counted as UNKNOWN.
Treat matched states with unusable timing data as UNKNOWN instead of
dropping them from the comparison. This includes missing, non-finite, or
non-positive timing centers, skipped states, and states with missing GPU
timing summaries.
Add explicit reason codes for these cases so the summary points users at
the underlying data issue. Preserve available timing data from the other
side when only one side is missing, and render unavailable durations as
n/a in all display modes.
Also sort values returned by np.unique_counts before nearest-neighbor
coverage checks so the distance algorithm receives ordered inputs.
Add regression coverage for UNKNOWN counting, skipped states, missing
summaries, unavailable center formatting, and the updated coverage helper.
This permits extracting Python script using Unix CLI tools
when `--bulk-debug-python stdout` is used.
Added example of using this to nvbench_compare.md doc.
Add compact reason labels for explain-mode tables while keeping canonical
reason codes in the undecided summary. Emit a one-line legend only for
non-trivial abbreviations.
Refine interval displays so timing values align across table rows:
- align Lo/Ce/Hi values in explain mode
- align center values in intervals mode when some rows lack interval bounds
- avoid repeating units when center and interval deltas use the same unit
Add a Change column for non-legacy displays so FAST/SLOW rows show the
signed interval-bound relative change, while SAME and UNDECIDED rows remain
blank.
Extend nvbench_compare tests to cover reason legend filtering, interval
alignment, missing-interval alignment, and Change column formatting.
Add versioned TOML configuration support for nvbench-compare threshold
settings. The new --config option reads grouped settings for clear-gap,
same-result, bulk coverage, and rare-support filtering thresholds. The parser
validates the schema strictly so unknown tables, unknown keys, invalid types,
unsupported versions, and out-of-range values fail early.
Add --dump-config to print the effective configuration without requiring input
JSON files. This makes the currently selected preset and resolved threshold
values discoverable and gives users a starting point for custom configuration.
Preset resolution is:
- default is used when neither TOML nor CLI selects a preset
- [preset] name = "..." in TOML selects the base preset
- --preset ... overrides the TOML preset selection
- explicit threshold values in TOML override whichever base preset was selected
For example:
- nvbench-compare --dump-config
Prints the built-in default settings as grouped TOML.
- nvbench-compare --preset permissive --dump-config
Prints the permissive preset values as TOML.
- nvbench-compare --config compare.toml ref.json cmp.json
Compares using the preset named in compare.toml, plus any explicit TOML
threshold overrides.
- nvbench-compare --config compare.toml --preset strict ref.json cmp.json
Uses the strict preset as the base, while preserving explicit threshold
overrides from compare.toml.
Keep TOML parsing lazy: Python 3.11+ uses tomllib, while Python 3.10 only
requires tomli when --config is used. Add focused tests for grouped config
dumping, strict validation, preset/override precedence, and CLI dump behavior.
Extend nvbench_compare with multiple table display modes and richer interval
formatting for timing comparisons.
Highlights:
- add `--display` with `intervals`, `legacy`, and `explain` modes
- keep `legacy` output using scalar Diff/%Diff
- make `intervals` the default, showing compact center-plus-delta timing
intervals
- add `explain` mode with explicit `[L | C | H]` interval rendering and
self-describing headers
- compute and store diff and relative-diff intervals in SummaryComparison
- add formatting helpers for absolute and relative interval displays
- make default preset slightly more permissive by lowering
`bulk_same_sample_coverage` to 0.97
Add focused tests covering:
- diff/%diff interval computation
- compact and explicit interval formatting
- default, legacy, and explain table layouts
- CLI propagation of `--display` and preset selection
Now:
- establish a candidate clear timing gap from summary timing intervals, as before
- if bulk sample times and frequencies are available on both sides,
compute cycles = time * frequency
- derive bulk cycle intervals from min/q1/median/q3
- confirm the gap direction from those bulk cycle intervals
- only fall back to summary sm_clock_rate_mean confirmation when bulk cycle data
is unavailable
I also split the reason codes so the evidence source is visible:
- clear_gap_confirmed_by_bulk_cycles
- bulk_cycle_gap_not_confirmed
- clear_gap_confirmed_by_summary_cycles
- summary_cycle_gap_not_confirmed
Updated tests in python/test/test_nvbench_compare.py cover both the bulk-confirmed
and bulk-rejected paths, along with the renamed summary reason codes.
Introduce comparison threshold presets in nvbench_compare and thread the
selected preset through main() into compare_benches.
Refine bulk nearest-neighbor support handling by:
- adding rare-support filtering thresholds
- ignoring low-count support values only when removed sample mass is small
- falling back to full support for all-unique or otherwise unusable support
- keeping sample-weight coverage over all values
Tighten bulk mismatch reporting to show compact min(ref, cmp) coverage
summaries, and add tests covering:
- rare-tail filtering
- strict fallback when too much support mass would be removed
- all-unique support preservation
- preset lookup and CLI preset propagation
Replace the scattered module-level comparison threshold constants
with a ComparisonThresholds value object. Thread this object through
compare_benches, compare_gpu_timings, and the lower-level clear-gap,
summary-SAME, and bulk-SAME decision helpers.
Keep existing behavior by constructing default ComparisonThresholds
when callers do not provide one. This prepares nvbench-compare for
future CLI-configurable decision thresholds while keeping one consistent
configuration for an entire comparison run.
Add test coverage that passes custom thresholds through compare_benches and
verifies they affect the SAME decision.
Add a bulk-data SAME path to nvbench_compare for cases where summary
intervals do not provide a clear FAST/SLOW decision. The new path compares
sample times and SM-clock-adjusted cycles with symmetric nearest-neighbor
coverage over unique values and sample counts.
The comparison now requires both sample-weight coverage and unique-support
coverage to pass before declaring SAME. If bulk data is available but coverage
does not pass, the result remains UNDECIDED instead of falling back to the
summary-only SAME rule.
Also improve undecided diagnostics by aggregating reason codes while preserving
the most severe representative detail, including observed coverage values and
thresholds for bulk support mismatches.
Add tests for:
- bulk data confirming SAME despite changed mode weights;
- bulk time mismatch overriding summary-only SAME;
- cycle coverage vetoing time-only agreement;
- sample-weight and unique-support coverage diagnostics;
- aggregation of undecided reason details.
- Add DecisionReason(code, message) and internal
TimingDecision(status, reason).
- SummaryComparison now carries reason
- ComparisonStats now aggregates undecided reasons.
- Final summary prints a reason breakdown only when
undecided reasons exist, e.g.:
- Undecided (comparison requires more evidence): 3
- Reasons:
- noise_too_high: 2 (relative dispersion is too
high to declare same)
- weak_interval_overlap: 1 (timing intervals do not
overlap strongly enough to declare same)
If SLOW/FAST check returned undecided, we attempt conservative
SAME check based on summary data alone (bulk data are not read)
Reference and compare measurements are considered SAME if
- both centers are positive finite values;
- abs(ref - cmp) / min(ref, cmp) <= 0.5%.
This is equivalent to max(ref, cmp) / min(ref, cmp) <= 1 + delta;
- interval overlap must cover at least 50% of the smaller interval;
- relative dispersion must be finite on both sides and no more than 2%;
- if SM clock summaries are available, the same check must also pass in cycle space.
Otherwise UNDECIDED remains working decision, to be refined by further checks
Implemented the clear-gap comparison, with the log-distance-equivalent
algebra and pessimistic SM-clock fallback.
What changed:
- Added TimingInterval and interval construction from summaries:
- robust interval: [min, q3], centered at median
- fallback interval: clipped [mean - stdev, mean + stdev] intersected with [min, max]
- Added CLEAR_GAP_RELATIVE_THRESHOLD = 0.005.
- FAST gap uses:
(ref.lower - cmp.upper) / cmp.upper >= delta
which is equivalent to log(ref.lower / cmp.upper) >= log(1 + delta).
- SLOW gap uses:
(cmp.lower - ref.upper) / ref.upper >= delta
- FAST/SLOW now requires SM clock summaries on both sides and the same clear-gap result after scaling intervals by sm_clock_rate_mean.
- If intervals are missing, overlap, fail the gap threshold, have missing/invalid clock summaries, or time/cycle comparison disagrees, status is UNDECIDED.
- Existing center/noise values are still computed and displayed, but no longer drive FAST/SLOW/SAME classification.
Updated tests to cover:
- center/noise-only comparisons becoming UNDECIDED
- clear FAST/SLOW with matching clock evidence
- missing clock fallback to UNDECIDED
- frequency-shift disagreement becoming UNDECIDED
- regression reporting with robust interval and clock evidence
Store JSON-bin sample time and frequency metadata in GpuTimingData instead of
reading the binary files during summary extraction.
Add Float32BinarySource and lazy cached accessors for samples and frequencies.
Use np.fromfile by default, but allow tests and alternate callers to inject a
float32 reader returning any buffer-compatible object convertable to "<f4" data
type.
Treat optional bulk-data failures as unavailable evidence instead of aborting
comparison: unreadable files, invalid buffers, count mismatches, and mismatched
sample/frequency metadata now emit RuntimeWarning and return None.
Update nvbench_compare tests to verify lazy loading, cache reuse, injected
reader behavior, warning-based degradation, and count mismatch handling.
Introduce GpuTimingData, SummaryComparison, ComparisonStats, and
ComparisonRunData to make timing extraction, classification, and run-level
state explicit.
Load sample-time and SM-frequency bulk data from JSON binary output into
GpuTimingData when available, preserving count validation between paired
sample and frequency arrays.
Move GPU timing comparison logic into compare_gpu_timings(), prefer robust
median/IQR data when available, and fall back to mean/stdev summaries otherwise.
Keep missing or invalid noise on the unknown path.
Replace module-level comparison counters and selected-device globals with
per-run data passed into compare_benches(). Update tests to validate timing
classification, bulk-data loading, device pairing, filtered duplicate matching,
and summary counters through the new structures.
Teach nvbench_compare to keep the order of --benchmark and --axis arguments so
axis filters can apply either globally or to the most recent benchmark. Build a
filter plan from the ordered CLI arguments and apply the same plan to table
output and plotting labels.
Add explicit --reference-devices and --compare-devices filters. The filters
accept all, a single device id, or a comma-separated list of ids; ordered lists
and duplicates are preserved so selected reference and compare devices can be
paired by position. Device-section mismatches remain fatal for unfiltered
all-vs-all comparisons, but become warnings when the user explicitly selects
devices and the selected device counts match.
Match duplicate benchmark states by occurrence within each filtered device
section instead of matching only by state name across the whole benchmark. This
keeps repeated axis values and filtered duplicate states aligned between the
reference and compare inputs, and reports mismatched occurrence counts instead
of silently dropping extra states.
Add Python tests for duplicate-state matching, axis filtering before matching,
device filter parsing and validation, explicit cross-device pairing, and
benchmark-scoped axis filters.
Original commit messages folded into this change:
Tweaks for nvbench_compare
1. When JSON files contain multiple entries with the same name and axis values,
make sure that scripts compares corresponding entries.
Previous logic would extract the first entry from ref data, and would compare
measurements for each state in cmp against the first entry from ref. The
change introduces a counter to know which nth entry we process for a
particular axis value, and retrieve corresponding entry in ref.
Scope occurrence matching by device.
Device pairing in nvbench_compare.py is strictly index-based under
--ignore-devices, reused IDs in a different order no longer pair against the
wrong reference device.
Require devices in ref and cmp to have the same cardinality
Handle mismatch when number of duplicates in ref data is not same as in cmp data
Use pytest monkeypatch fixture to pretend third-party package dependencies are
available during test run for nvbench_compare without introducing test-time
dependency
Added the happy-path test and fixed its direct-call setup by initializing the
device globals that main() normally populates.
Fix to filter-before-matching.
- compare_benches() now pairs devices by selected position instead of taking a
device id.
- For each device pair, compare_benches() now builds:
- ref_device_states: matching reference device and axis filters
- cmp_device_states: matching compare device and axis filters
- State occurrence counts and duplicate occurrence matching now operate only
on those filtered per-device lists.
- Removed the later matches_axis_filters() skip inside the compare-state loop
because filtering now happens before matching.
Added a regression test where ref/cmp have duplicate state names in opposite
order, and --axis keeps only one of them. The test verifies the kept compare
state is matched against the kept reference state, not the first unfiltered
occurrence.
Introduce device filtering in nvbench_compare
- --reference-devices all|ID|ID,ID,...
- --compare-devices all|ID|ID,ID,...
- Integer lists preserve order and duplicates.
- Requested IDs are validated against the file-level device list.
- Filtered reference/compare device counts must match before comparison.
- compare_benches() pairs selected reference and compare devices by position.
- Each benchmark validates that requested device IDs are present in its own
devices list.
Implemented benchmark-scoped --axis handling.
- --axis and --benchmark now share an ordered argparse action, so their
relative CLI order is preserved.
- -a before any -b becomes a global axis filter.
- -a after -b <name> applies to that most recent benchmark only.
- Repeated -b entries are treated as separate filter scopes and combined as
alternatives for that benchmark.
- Device filtering remains global and is applied independently.
Allow non-matching devices for explicit device selection
Now the device-section equality check remains fatal only for unfiltered
all-vs-all comparisons. If either --reference-devices or --compare-devices is
explicit, mismatched selected device metadata is printed as a warning, but
comparison proceeds after the selected device counts have been validated.
Fix for resolve_benchmark_device_ids, add comments
The return value of resolve_benchmark_device_ids now always owns its list.
Use monkeypatch class in set_test_devices helper
Stricted device id validation
Test for device id validation
Teach nvbench_compare to parse GPU timing summaries into structured values and
prefer the robust median/IQR summaries when both compared measurements provide
them. Fall back to the existing mean/stdev summaries when robust summaries are
not available.
Classify comparisons with the larger available relative noise estimate instead
of the smaller one, keep unavailable noise distinct from encoded infinite noise,
and report improvements separately from regressions. Keep the process exit code
as success for completed comparisons; regression counts are reported in the
summary instead of being used as the process status.
Make plotting tolerate unavailable noise by leaving gaps in confidence bands,
sort plotted series by the plotted axis, and avoid reusing pyplot state across
plot calls.
Add focused Python tests for robust-summary preference, unavailable-noise
classification, non-finite timing centers, plot-along handling when the selected
axis is absent, and the exit-code contract.
* Add decorators for registering benchmarks and adding axis
cuda.bench.register(fn) continues returning Benchmark, and supports
legacy use.
New signature added:
cuda.bench.register():
Returns a decorator
```
@bench.register()
@bench.axis.float64("Duration (s)", [7e-5, 1e-4, 5e-4])
@bench.option.min_samples(120)
def single_float64_axis(state: bench.State):
...
```
* Remove example/auto_throughput.py
The C++ counterpart's purpose is to demonstrate use of CUPTI
metrics, but these are not supported in Python bindings, so
this example is a duplicate of example/throughput.py
* Add wrong decorator order test for bench.axis.*
* Strengthen type annotation for register function
Acting on code rabbit nit-pick require that function being
registered take cuda.bench.State object as an argument.
Verified the fix as
```
(py313) :~/repos/nvbench/python$ python -m mypy --ignore-missing-import /tmp/t.py
/tmp/t.py:8: error: Argument 1 has incompatible type "Callable[[], None]"; expected "Callable[[State], None]" [arg-type]
Found 1 error in 1 file (checked 1 source file)
(py313) :~/repos/nvbench/python$ nl -ba /tmp/t.py
1 # /tmp/check_nvbench_register.py
2 import cuda.bench as bench
3
4 @bench.register()
5 def good(state: bench.State) -> None:
6 pass
7
8 @bench.register()
9 def bad() -> None:
10 pass
```
* Replace use of global variable with thread-safe lru_cache
This improves thread-safety of module initialization.
* Abide by RUF005 linting rule
* Expand docstrings regarding cuda.bench.register() decorator
It explains to the user what the decorator does and provides
a concise usage example.
* Sharpen wording on exception maybe-thrown by decorator
Implements `cuda.bench.results.BenchmarkResult` class to represent data from JSON output of benchmark execution.
The contains implements two class methods `BenchmarkResult.from_json(filename : str | os.PathLike, *, metadata : Any = None)` which expects well-formed JSON filename and `BenchmarkResult.empty(*, metadata : Any = None)` intended to represent failed result with reasons that can be recorded in metadata at user's discretion.
The `BenchmarkResult` implements mapping interface, supporting `.keys()`, `.values()`, `.items()` methods, `__len__`, `__contains__`, `__getitem__` and `__iter__` special methods.
Values in `BenchmarkResult` has type `cuda.bench.results.SubBenchmarkResult` which implements a list-like interface, i.e. implements `__len__`, `__getitem__`, and `__iter__` special methods. Values in this list-like structure correspond to measurements of individual states of a particular benchmark (the key in `BenchmarkResult`).
Elements of `SubBenchmarkResult` structure have type `SubBenchmarkState` that supports mapping protocol with axis_values as a key and represent data corresponding to measurements for a particular state (combination of settings for each axis).
The state provides `.samples` and `.frequencies` attributes storing raw execution duration values and estimates for average GPU frequencies.
Example usage:
```
import array, numpy as np, cuda.bench.results
r = cuda.bench.results.BenchmarkResult("perf_data/axes_run1.json")
r["copy_sweep_grid_shape"].centers_with_frequencies(
lambda t, f: np.median(np.asarray(t)*np.asarray(f)))
```
```
In [1]: import array, numpy as np, cuda.bench.results
In [2]: r = cuda.bench.results.BenchmarkResult("temp_data/axes_run1.json")
In [3]: list(r)
Out[3]:
['simple',
'single_float64_axis',
'copy_sweep_grid_shape',
'copy_type_sweep',
'copy_type_conversion_sweep',
'copy_type_and_block_size_sweep']
In [4]: r["simple"].centers(lambda t: np.percentile(t, [25,75]))
Out[4]: {'Device=0': array([0.00100966, 0.00101299])}
In [5]: r.centers(lambda t: np.percentile(t, [25,75]))["simple"]
Out[5]: {'Device=0': array([0.00100966, 0.00101299])}
In [6]: len(r)
Out[6]: 6
In [7]: "fake" in r
Out[7]: False
```
Each `SubBenchmarkState` implements
`.summaries` attribute - rich object that retains tag/name/hint/hide/description metadata.
* Add nvbench-json-summary to render NVBench JSON output as an NVBench-style
markdown summary table, including axis formatting, device sections, hidden
summary filtering, and summary hint formatting.
Update packaging, type stubs, and tests for the new namespace, renamed
classes, Python 3.10-compatible annotations, and summary-table generation.
* Split tests in test_benchmark_result into smaller tests
* Fix break due to file name change
* Add python/examples/benchmark_result_autotune.py
This example demonstrates using cuda.bench and cuda.bench.results
to implement simple auto-tuning, demonstrated on selecting of
tile shape hyperparameter for naive stencil kernel implemented
in numba-cuda.
* Resolve ruff PLE0604
* Fix for format_axis_value in json format script to handle None value
Add tests to cover such input.
* Address code rabbit review feedback
* Fix license header, add validation
* Addressed both issues raised in review
Malformed values are now represented in result as None.
Skipped benchmarks are no longer dropped, i.e., they are present
in BenchmarkResult data, but they are not reflected in summary
table in line with what NVBench-instrumented benchmarks do.
* Correct Python API signature of State.get_axis_values_as_strings
The C++ API has default boolean argument color, but Python API
declared no arguments.
Closes#345
* Also exercise invocation of get_axis_values_as_string with keyword argument value
* Remove use of cuda.core.experimental
Fixed relative text alignment in docstrings to fix autodoc warnigns
Renamed cuda.bench.test_cpp_exception and cuda.bench.test_py_exception functions
to start with underscore, signaling that these functions are internal and should
not be documented
Account for test_cpp_exceptions -> _test_cpp_exception, same for *_py_*
Make sure to reset __module__ of reexported symbols to be cuda.bench
* Introduce function colorize to modularize colorization/no-color handling
* Use sns.set_theme instead of deprecated sns.set()
* Use str.format instead of legacy % syntax
* Simplified iteration over list
Use f-string (supported since Python 3.6) instead of str.format for
better readability and performance
