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feat(sim): add L40S GPU and FP8 compute support#765

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pr762-fp8-hardware-support
Mar 20, 2026
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feat(sim): add L40S GPU and FP8 compute support#765
sriumcp merged 19 commits intomainfrom
pr762-fp8-hardware-support

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@susiejojo susiejojo commented Mar 19, 2026

Summary

Extends hardware support for BLIS-roofline with L40S GPU and native FP8 compute capabilities for H100.

Changes

1. L40S GPU Support

  • Added L40S hardware configuration (362.05 TFLOPS, 48GB, 0.864 TB/s)
  • Calibrated MFU values: prefill=0.32, decode=0.08

2. FP8 Compute Support

  • Added TFlopsFP8 field to HardwareCalib struct
  • H100: TFlopsFP8=1979.0 (2× FP16 rate, native FP8 tensor cores)
  • A100: TFlopsFP8=0 (W8A16 via Marlin kernels, no native FP8)
  • L40S: TFlopsFP8=0 (W8A16 via Marlin kernels, no native FP8)

3. Roofline Model Updates

  • Implemented FP8 compute selection logic in rooflineStepTime()
  • For FP8 weights (1 byte/param) on H100: uses 2× faster FP8 compute rate
  • For FP8 weights on A100/L40S: uses FP16 rate (weights upcasted for compute)

4. MFU Calibration Updates

  • H100: prefill=0.45, decode=0.30 (unchanged from baseline)
  • A100-SXM/A100-80: prefill=0.38, decode=0.18 (calibrated for inference workloads)
  • L40S: prefill=0.32, decode=0.08 (bandwidth-constrained PCIe GPU)

MFU Value Justification

The MFU (Model FLOPs Utilization) values in this PR are calibrated based on empirical evidence and roofline model theory. For detailed justification including:

  • Evidence from FlashAttention-3, NVIDIA MLPerf, and production deployments
  • Cross-GPU validation and bandwidth-proportional scaling
  • Conservative bias for capacity planning
  • Academic references (Shah et al. 2024, Korthikanti et al. 2022, etc.)

See: Discussion #589 - Roofline Physics Model: Evidence & Literature Justification

Testing

  • Added 4 comprehensive test functions covering H100, A100, L40S, and edge cases
  • All tests pass (go test ./... -count=1)
  • Build successful (go build ./...)

Fixes #762

susiejojo and others added 14 commits March 19, 2026 10:14
…#443)

Roofline and KV capacity calculations now correctly use quantized weight
precision (e.g. 0.5 bytes/param for W4A16) for weight memory while keeping
the compute dtype (e.g. 2.0 for bfloat16) for KV cache and activations.

- Add WeightBytesPerParam field to ModelConfig with zero-value sentinel
- Parse quantization_config from HuggingFace config.json (GPTQ, AWQ, FP8)
- Add --weight-bytes-per-param CLI flag for manual override
- Update calculateMemoryAccessBytes() and computeModelWeightBytes()
- Add validation in ValidateRooflineConfig
- 18 new tests covering all behavioral contracts

Co-Authored-By: Claude Opus 4.6 <[email protected]>
…uant warnings

Address 3 IMPORTANT findings from convergence review Round 1:

1. Apply --weight-bytes-per-param CLI override in blackbox KV auto-calc
   path (R23: code path parity with analytical backend)
2. Add WeightBytesPerParam validation in CalculateKVBlocks public API
3. Warn when quantization_config is present but weight precision could
   not be auto-detected (both analytical and blackbox paths)

Co-Authored-By: Claude Opus 4.6 <[email protected]>
Move --weight-bytes-per-param validation before backend switch to avoid
Fatalf inside the best-effort blackbox block (preserves fall-through
contract). Make weight precision log backend-specific: roofline uses it
for step time; trained-roofline/crossmodel only for KV capacity.

Co-Authored-By: Claude Opus 4.6 <[email protected]>
Convergence R3: gofmt -w to re-align ModelConfig struct fields and
cmd/root.go var block after longest field name changed.

Co-Authored-By: Claude Opus 4.6 <[email protected]>
Add code comment in rooflineStepTime noting that MFU values were
calibrated against FP16 measurements. For quantized models (W4A16),
reduced weight bandwidth shifts the roofline crossover, producing
conservative estimates — safe for capacity planning.

Co-Authored-By: Claude Opus 4.6 <[email protected]>
…verage, validation comment

- Use strings.EqualFold for FP8 quant_method matching (case-insensitive)
- Add test for FP8 with bits=8 present (verifies bits-first path agrees)
- Document why WeightBytesPerParam > BytesPerParam is accepted in validation

Co-Authored-By: Claude Opus 4.6 <[email protected]>
… CLI flag

Add compressed-tensors parsing (config_groups.*.weights.num_bits) to close
the gap where w8a8 models silently fell back to torch_dtype. Add model name
convention detection (w4a16, fp8) as a second-tier fallback. Remove the
--weight-bytes-per-param CLI flag — all three issue #443 options are now
covered by auto-detection, making the manual override unnecessary.

Detection chain: quantization_config → model name → torch_dtype fallback.

Co-Authored-By: Claude Opus 4.6 <[email protected]>
…verage, validation comment

C1: Extract applyWeightPrecisionFallback shared helper (cmd/hfconfig.go)
    and add model name fallback to cmd/replay.go roofline path (was missing).
    Three call sites (root.go blackbox, root.go roofline, replay.go) now
    share identical fallback + logging logic.

C2: Sort config_groups keys before iteration in compressed-tensors
    parsing (INV-6 determinism).

I2: Add string-to-int coercion for quantization_config.bits field
    (handles "bits": "4" from some HF configs).

I3: Add TestRooflineStepTime_W4A16_LowerThanFP16_MemoryBoundDecode
    end-to-end test verifying quantized model produces lower decode
    step time than FP16 in memory-bound regime.

I4: Add TestValidateRooflineConfig_InfWeightBytesPerParam_ReturnsError
    covering +Inf validation gap.

Minor: Remove double blank line in root.go init().

Co-Authored-By: Claude Opus 4.6 <[email protected]>
… and extension recipes

Five documentation pages still claimed quantization was "not yet modeled" and
recommended blackbox mode, contradicting the three-tier auto-detection merged
in this branch. Addresses PR #698 review comments D1–D5.

Co-Authored-By: Claude Opus 4.6 <[email protected]>
…on (I4)

Trained-roofline hardcodes FP16 bytesPerElement to match its training
pipeline, so WeightBytesPerParam only affects KV capacity, not step time.
Previously the CLI logged "quantized model detected" without mentioning
this limitation, which was misleading. Now emits an explicit warning in
both run and replay paths.

Addresses review item I4 from PR #698 convergence review.

Co-Authored-By: Claude Opus 4.6 <[email protected]>
- Add bitsPerByte constant to replace magic number 8.0 (issue #6)
- Improve roofline approximation comment with quantitative guidance (issue #8)
…prove code quality

- Extract quantization parsing into parseQuantizationConfig helper (Issue #4)
- Consolidate duplicated trained-roofline warning into warnTrainedRooflineQuantization helper (Issue #1)
- Add validation warning when WeightBytesPerParam > BytesPerParam (Issue #2)
- Add debug logging for malformed compressed-tensors config_groups (Issue #3)
- Add error handling for invalid bits string-to-int coercion (Issue #5)
- Add comment explaining first-match semantics in compressed-tensors parsing (Issue #7)
- Fix inconsistent spacing in string concatenation (Issue #9)

All changes maintain backward compatibility and pass existing tests.
- Add L40S hardware configuration (362.05 TFLOPS, 48GB, 0.864 TB/s)
- Add TFlopsFP8 field to HardwareCalib for native FP8 tensor core support
- Update H100 with TFlopsFP8=1979.0 (2× FP16 rate) and adjusted MFU values
- Update A100-SXM and A100-80 with TFlopsFP8=0 (no native FP8 support)
- Implement FP8 compute selection in roofline model based on weight precision
- Add comprehensive tests for FP8 compute selection logic

Fixes #762

Co-Authored-By: Claude <[email protected]>
@susiejojo susiejojo force-pushed the pr762-fp8-hardware-support branch 2 times, most recently from fbec9c4 to 66205db Compare March 19, 2026 19:16
@susiejojo susiejojo requested a review from sriumcp March 19, 2026 19:19
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Multi-Perspective Code Review

I've completed a thorough review of this PR through 10 different perspectives (substance & design, code quality, test quality, user experience, automated review simulation, DES expert, vLLM expert, distributed systems expert, performance, and security). Here are the findings:

🔴 High Priority

Missing validation for TFlopsFP8 field in ValidateRooflineConfig

  • Location: sim/latency/config.go:354-365
  • Issue: The new TFlopsFP8 field is not validated in ValidateRooflineConfig(). While TFlopsFP8=0 is valid (no native FP8 support), negative values, NaN, or Inf should be rejected.
  • Impact: Could allow invalid hardware configurations to pass validation and cause runtime issues.
  • Suggestion: Add validation after line 356:
if hc.TFlopsFP8 != 0 && invalidPositiveFloat(hc.TFlopsFP8) {
    problems = append(problems, fmt.Sprintf("HardwareCalib.TFlopsFP8 must be >= 0 and finite when set, got %v", hc.TFlopsFP8))
}

🟡 Medium Priority

Hardware config JSON lacks inline documentation for new fields

  • Location: hardware_config.json:4
  • Issue: The TFlopsFP8 field lacks explanation of what it represents, when it should be 0, or its relationship to TFlopsPeak.
  • Suggestion: Add a top-level comment explaining the field:
"_TFlopsFP8_info": "FP8 tensor core throughput in TFLOPS. Set to 0 for GPUs without native FP8 support (A100, L40S). H100 has 2× FP16 rate."

FP8 selection logic doesn't handle WeightBytesPerParam between 1.0 and 2.0

  • Location: sim/latency/roofline.go:219
  • Issue: The condition uses exact equality == 1.0 to detect FP8 weights. Values between 1.0 and 2.0 (e.g., 1.5 for mixed precision) would incorrectly use FP16 compute rate.
  • Suggestion: Consider if the condition should be <= 1.0 or add validation to restrict WeightBytesPerParam to known quantization levels (0.5, 1.0, 2.0, 4.0).

🟢 Low Priority

MFU value changes for A100 not explained or tested

  • Location: hardware_config.json:13-15
  • Issue: A100 MFU values changed significantly (prefill: 0.45→0.38, decode: 0.30→0.18) without explanation or test coverage. L40S values (0.32, 0.08) are even lower.
  • Suggestion: Add a comment citing the source for MFU values, or add tests validating these produce expected latencies.

Inconsistent decimal formatting in mfuDecode field

  • Location: hardware_config.json:7
  • Issue: H100's mfuDecode changed from 0.30 to 0.3, while other entries use consistent decimal places.
  • Suggestion: Change to 0.30 for consistency.

Roofline comment could clarify W8A16 kernel behavior more precisely

  • Location: sim/latency/roofline.go:213-217
  • Issue: The phrase "weights upcasted to FP16 for compute" could be more precise about on-the-fly dequantization.
  • Suggestion: Clarify: "while A100/L40S use W8A16 via Marlin kernels (weights dequantized to FP16 during GEMM, preserving FP16 compute rate)"

Test helper testHardwareCalib() doesn't include TFlopsFP8

  • Location: sim/latency/roofline_test.go:184-191
  • Issue: The helper doesn't set TFlopsFP8, leaving it as zero. Future tests using this helper might miss FP8 scenarios.
  • Suggestion: Add TFlopsFP8: 0 explicitly for clarity, or create a separate testHardwareCalibFP8() helper.

✅ Positive Findings

  • Core FP8 selection logic is correct and well-commented
  • Comprehensive test coverage with behavioral GIVEN/WHEN/THEN patterns
  • Tests cover H100 (native FP8), A100 (no FP8), L40S, and edge cases
  • No performance regressions or DES invariant violations
  • No security issues beyond the validation gap

susiejojo added a commit that referenced this pull request Mar 19, 2026
- Add TFlopsFP8 validation in ValidateRooflineConfig (negative, NaN, Inf rejected; zero allowed)
- Add inline documentation for TFlopsFP8 field in hardware_config.json
- Fix FP8 selection logic to use <= 1.0 instead of == 1.0 (handles mixed precision)
- Add comprehensive tests for TFlopsFP8 validation

Addresses review comments from PR #765
susiejojo added a commit that referenced this pull request Mar 19, 2026
- Add TFlopsFP8 validation in ValidateRooflineConfig (negative, NaN, Inf rejected; zero allowed)
- Add inline documentation for TFlopsFP8 field in hardware_config.json
- Fix FP8 selection logic to use <= 1.0 instead of == 1.0 (handles mixed precision)
- Add comprehensive tests for TFlopsFP8 validation

Addresses review comments from PR #765
@susiejojo susiejojo force-pushed the pr762-fp8-hardware-support branch from 2bc8682 to 06c5d4d Compare March 19, 2026 20:53
susiejojo added a commit that referenced this pull request Mar 19, 2026
- Add TFlopsFP8 validation in ValidateRooflineConfig (negative, NaN, Inf rejected; zero allowed)
- Add inline documentation for TFlopsFP8 field in hardware_config.json
- Fix FP8 selection logic to use <= 1.0 instead of == 1.0 (handles mixed precision)
- Add comprehensive tests for TFlopsFP8 validation

Addresses review comments from PR #765
@susiejojo susiejojo force-pushed the pr762-fp8-hardware-support branch from 06c5d4d to 6a041e0 Compare March 19, 2026 20:56
susiejojo added a commit that referenced this pull request Mar 19, 2026
- Add TFlopsFP8 validation in ValidateRooflineConfig (negative, NaN, Inf rejected; zero allowed)
- Add inline documentation for TFlopsFP8 field in hardware_config.json
- Fix FP8 selection logic to use <= 1.0 instead of == 1.0 (handles mixed precision)
- Add comprehensive tests for TFlopsFP8 validation

Addresses review comments from PR #765
@susiejojo susiejojo force-pushed the pr762-fp8-hardware-support branch from 6a041e0 to a1bde43 Compare March 19, 2026 20:58
- Add inline documentation to hardware_config.json linking to Discussion #589
- Add comprehensive MFU validation tests in sim/config_test.go
  - Validates MFU ranges (0 < MFU < 1)
  - Validates MfuDecode < MfuPrefill relationship
  - Tests all GPU types (H100, A100, L40S)
- Update docs/reference/models.md with MFU calibration info box
- All tests pass

Addresses review findings from quick-review
@susiejojo susiejojo force-pushed the pr762-fp8-hardware-support branch from a1bde43 to be177ab Compare March 20, 2026 14:24
susiejojo added a commit that referenced this pull request Mar 20, 2026
- Add TFlopsFP8 validation in ValidateRooflineConfig (negative, NaN, Inf rejected; zero allowed)
- Add inline documentation for TFlopsFP8 field in hardware_config.json
- Fix FP8 selection logic to use <= 1.0 instead of == 1.0 (handles mixed precision)
- Add comprehensive tests for TFlopsFP8 validation

Addresses review comments from PR #765
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Follow-up review — unaddressed items from previous round

The high-priority validation gap and several lower-priority items from the previous review remain open. Summary below; inline comments added at specific locations.

🔴 R3 violation — TFlopsFP8 not validated in ValidateRooflineConfig

sim/latency/config.go was not changed in this PR. ValidateRooflineConfig validates every other HardwareCalib field (TFlopsPeak, BwPeakTBs, MfuPrefill, MfuDecode, MemoryGiB) but not TFlopsFP8. Negative values, NaN, and Inf will silently pass validation and propagate into rooflineStepTime where TFlopsFP8 * 1e12 would yield a nonsensical peakFlops. The existing invalidPositiveFloat helper can be reused with the same optional-field pattern used for MemoryGiB:

// in ValidateRooflineConfig, after the MemoryGiB block:
if hc.TFlopsFP8 != 0 {
    if math.IsNaN(hc.TFlopsFP8) || math.IsInf(hc.TFlopsFP8, 0) || hc.TFlopsFP8 < 0 {
        problems = append(problems, fmt.Sprintf(
            "HardwareCalib.TFlopsFP8 must be >= 0 and finite when set, got %v", hc.TFlopsFP8))
    }
}

🟡 R4 concern — two HardwareCalib construction sites omit TFlopsFP8

R4 requires auditing all construction sites when a struct gains a new field. Two sites outside the diff still use positional-style partial literals:

  • sim/latency/roofline_test.go:185testHardwareCalib() helper (used at 8+ call sites) has no TFlopsFP8 field, leaving it implicitly zero. Since the helper is advertised as "H100-like", the intent (TFlopsFP8: 0 = treating it as a non-FP8 baseline, not the H100 value of 1979.0) should be made explicit.
  • sim/config_test.go:45hw := HardwareCalib{TFlopsPeak: 1000.0, MemoryGiB: 80.0} omits TFlopsFP8.

Neither is a runtime bug (zero is the correct default for "no native FP8"), but documenting intent prevents future readers from treating them as oversights.

🟢 Minor nits

  • hardware_config.json:8 — H100 mfuDecode changed from 0.30 to 0.3; all other entries use two decimal places (see inline comment).
  • roofline.go:217 — "weights upcasted to FP16 for compute" is imprecise; see inline comment.

type HardwareCalib struct {
TFlopsPeak float64 `json:"TFlopsPeak"` // Tera (10^12) FLOP/s
TFlopsPeak float64 `json:"TFlopsPeak"` // Tera (10^12) FLOP/s for FP16/BF16 compute
TFlopsFP8 float64 `json:"TFlopsFP8"` // Tera (10^12) FLOP/s for FP8 compute; 0 = no native FP8 support
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R3 — is added to here but is not validated in (sim/latency/config.go). Every other field in this struct (, , , , ) has a validation guard; needs one too. The existing optional-field pattern from applies directly: check then reject NaN/Inf/negative.

Add validation for HardwareCalib.TFlopsFP8 in ValidateRooflineConfig,
following the same optional-field pattern as MemoryGiB: check if non-zero,
then reject NaN/Inf/negative values.

Includes test coverage for NaN and negative TFlopsFP8 cases.
- roofline.go:217: Fix comment wording from 'upcasted' to 'dequantized to FP16 during GEMM'
- hardware_config.json:8: Restore H100 mfuDecode to 0.30 for consistency with other entries
Improve comment to explicitly document that == 1.0 is intentional:
- FP8 models (exactly 1.0 byte/param) use FP8 compute rate on H100
- Sub-FP8 formats (e.g., W4A16 at 0.5 bytes/param) dequantize to FP16 during GEMM

This addresses the review comment about == 1.0 exact equality. The behavior
is correct: only true FP8 models use FP8 tensor cores. W4A16 and other
sub-FP8 formats use FP16 compute after dequantization, as validated by
TestRooflineStepTime_FP8ComputeSelection_EdgeCases.
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susiejojo commented Mar 20, 2026

Addressed all review comments from review #3981973061:

R3 - TFlopsFP8 validation (326f44f):

  • Added validation for HardwareCalib.TFlopsFP8 in ValidateRooflineConfig following the same optional-field pattern as MemoryGiB
  • Added test coverage: TestValidateRooflineConfig_NaNTFlopsFP8_ReturnsError and TestValidateRooflineConfig_NegativeTFlopsFP8_ReturnsError

Comment and formatting nits (45d4cd5):

  • Fixed comment wording from "upcasted" to "dequantized to FP16 during GEMM"
  • Restored H100 mfuDecode to 0.30 for consistency with other entries

FP8 compute rate selection (6a12a37):

  • Clarified that == 1.0 is intentional: only true FP8 models (1.0 byte/param) use FP8 compute rate
  • Documented that sub-FP8 formats (e.g., W4A16 at 0.5 bytes/param) dequantize to FP16 during GEMM and use FP16 rate
  • This behavior is validated by TestRooflineStepTime_FP8ComputeSelection_EdgeCases

Verification: W4A16 uses FP16 compute rate (not FP8)

I investigated the vLLM source code to verify W4A16 behavior and confirm the == 1.0 check is correct:

Key Findings from vLLM:

  1. W4A16 = 4-bit weights + FP16 activations — Uses FP16 tensor cores, not FP8

    • Confirmed across multiple files: CompressedTensorsW4A16Fp4, CompressedTensorsW4A16Sparse24, etc.
  2. Marlin kernels operate in FP16/BF16 precision

    • Source: csrc/quantization/gptq_marlin/gptq_marlin.cu:31-32
    • static_assert(std::is_same<scalar_t, half>::value || std::is_same<scalar_t, nv_bfloat16>::value, "only float16 and bfloat16 is supported");
  3. W4A8-FP8 is a completely separate mode

    • Requires explicit environment variable: VLLM_MARLIN_INPUT_DTYPE=fp8
    • Only works on H100+ (SM89+) or SM120 devices
    • Source: marlin_utils.py:492-511
    • The code explicitly states: "It is slower than Marlin W4A16 on other devices"
  4. The == 1.0 check correctly identifies FP8 weights

    • FP8 weights: 1.0 bytes/param → Use FP8 tensor cores
    • W4A16 weights: 0.5 bytes/param → Use FP16 tensor cores
    • FP16 weights: 2.0 bytes/param → Use FP16 tensor cores

Conclusion

W4A16 quantization refers to the weight precision (4-bit) and activation precision (FP16), not the compute precision. The actual matrix multiplications happen in FP16 precision after dequantizing the 4-bit weights on-the-fly during GEMM operations.

The current implementation is correct — only models with true FP8 weights (1.0 bytes/param) should use FP8 tensor cores. Sub-FP8 quantization formats like W4A16 (0.5 bytes/param) correctly use FP16 compute rate.

All tests pass.

@susiejojo susiejojo requested a review from sriumcp March 20, 2026 15:10
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LGTM — ready to merge with one micro-nit still open

Addressed since previous round

Item Status
R3TFlopsFP8 validation in ValidateRooflineConfig ✅ Fixed (config.go:404-410), with NaN and negative test cases in config_test.go
Comment precision — "upcasted" → "dequantized to FP16 during GEMM" ✅ Fixed (roofline.go:217)
== 1.0 undocumented intent ✅ Addressed — new comment explicitly names "FP8 models (exactly 1 byte/param)" vs "Sub-FP8 formats (e.g., W4A16 at 0.5 bytes/param)"
mfuDecode: 0.30.30 formatting ✅ Fixed

Still open (non-blocking)

The two R4 construction sites flagged in the previous round were not updated:

  • sim/latency/roofline_test.go:185testHardwareCalib() still omits TFlopsFP8: 0
  • sim/config_test.go:45HardwareCalib{TFlopsPeak: 1000.0, MemoryGiB: 80.0} still omits TFlopsFP8: 0

Neither is a correctness issue — 0 is the correct default for "no native FP8 support" and both helpers behave exactly as intended. I'm not blocking on this. The only reason R4 asks for explicit fields even when the zero is correct is to make intent legible to the next reader. Consider adding TFlopsFP8: 0 with a brief inline comment (e.g., // W8A16 only — no native FP8) at some point; a follow-up commit is fine.

All correctness and standards issues are resolved. Approving.

@sriumcp sriumcp merged commit cad4191 into main Mar 20, 2026
4 of 5 checks passed
vishakha-ramani pushed a commit to atantawi/inference-sim that referenced this pull request Mar 20, 2026
* feat(latency): decouple quantized weight precision from compute dtype (inference-sim#443)

Roofline and KV capacity calculations now correctly use quantized weight
precision (e.g. 0.5 bytes/param for W4A16) for weight memory while keeping
the compute dtype (e.g. 2.0 for bfloat16) for KV cache and activations.

- Add WeightBytesPerParam field to ModelConfig with zero-value sentinel
- Parse quantization_config from HuggingFace config.json (GPTQ, AWQ, FP8)
- Add --weight-bytes-per-param CLI flag for manual override
- Update calculateMemoryAccessBytes() and computeModelWeightBytes()
- Add validation in ValidateRooflineConfig
- 18 new tests covering all behavioral contracts

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix(latency): convergence R1 — blackbox path parity, KV validation, quant warnings

Address 3 IMPORTANT findings from convergence review Round 1:

1. Apply --weight-bytes-per-param CLI override in blackbox KV auto-calc
   path (R23: code path parity with analytical backend)
2. Add WeightBytesPerParam validation in CalculateKVBlocks public API
3. Warn when quantization_config is present but weight precision could
   not be auto-detected (both analytical and blackbox paths)

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix(cmd): convergence R2 — early flag validation, backend-specific logs

Move --weight-bytes-per-param validation before backend switch to avoid
Fatalf inside the best-effort blackbox block (preserves fall-through
contract). Make weight precision log backend-specific: roofline uses it
for step time; trained-roofline/crossmodel only for KV capacity.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* style: gofmt struct/var alignment after WeightBytesPerParam addition

Convergence R3: gofmt -w to re-align ModelConfig struct fields and
cmd/root.go var block after longest field name changed.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* style: gofmt const/map alignment in kv_capacity files

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* docs: document MFU calibration approximation for quantized models

Add code comment in rooflineStepTime noting that MFU values were
calibrated against FP16 measurements. For quantized models (W4A16),
reduced weight bandwidth shifts the roofline crossover, producing
conservative estimates — safe for capacity planning.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix(latency): address PR review — FP8 case-insensitive match, test coverage, validation comment

- Use strings.EqualFold for FP8 quant_method matching (case-insensitive)
- Add test for FP8 with bits=8 present (verifies bits-first path agrees)
- Document why WeightBytesPerParam > BytesPerParam is accepted in validation

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* feat(latency): complete three-tier quantized weight detection, remove CLI flag

Add compressed-tensors parsing (config_groups.*.weights.num_bits) to close
the gap where w8a8 models silently fell back to torch_dtype. Add model name
convention detection (w4a16, fp8) as a second-tier fallback. Remove the
--weight-bytes-per-param CLI flag — all three issue inference-sim#443 options are now
covered by auto-detection, making the manual override unnecessary.

Detection chain: quantization_config → model name → torch_dtype fallback.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix(latency): address PR review — FP8 case-insensitive match, test coverage, validation comment

C1: Extract applyWeightPrecisionFallback shared helper (cmd/hfconfig.go)
    and add model name fallback to cmd/replay.go roofline path (was missing).
    Three call sites (root.go blackbox, root.go roofline, replay.go) now
    share identical fallback + logging logic.

C2: Sort config_groups keys before iteration in compressed-tensors
    parsing (INV-6 determinism).

I2: Add string-to-int coercion for quantization_config.bits field
    (handles "bits": "4" from some HF configs).

I3: Add TestRooflineStepTime_W4A16_LowerThanFP16_MemoryBoundDecode
    end-to-end test verifying quantized model produces lower decode
    step time than FP16 in memory-bound regime.

I4: Add TestValidateRooflineConfig_InfWeightBytesPerParam_ReturnsError
    covering +Inf validation gap.

Minor: Remove double blank line in root.go init().

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* docs: update quantization support language across guides, references, and extension recipes

Five documentation pages still claimed quantization was "not yet modeled" and
recommended blackbox mode, contradicting the three-tier auto-detection merged
in this branch. Addresses PR inference-sim#698 review comments D1–D5.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix(cmd): warn when trained-roofline ignores quantized weight precision (I4)

Trained-roofline hardcodes FP16 bytesPerElement to match its training
pipeline, so WeightBytesPerParam only affects KV capacity, not step time.
Previously the CLI logged "quantized model detected" without mentioning
this limitation, which was misleading. Now emits an explicit warning in
both run and replay paths.

Addresses review item I4 from PR inference-sim#698 convergence review.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix: address cosmetic review comments

- Add bitsPerByte constant to replace magic number 8.0 (issue #6)
- Improve roofline approximation comment with quantitative guidance (issue #8)

* Address PR inference-sim#698 review feedback: refactor quantization parsing and improve code quality

- Extract quantization parsing into parseQuantizationConfig helper (Issue #4)
- Consolidate duplicated trained-roofline warning into warnTrainedRooflineQuantization helper (Issue inference-sim#1)
- Add validation warning when WeightBytesPerParam > BytesPerParam (Issue #2)
- Add debug logging for malformed compressed-tensors config_groups (Issue #3)
- Add error handling for invalid bits string-to-int coercion (Issue #5)
- Add comment explaining first-match semantics in compressed-tensors parsing (Issue #7)
- Fix inconsistent spacing in string concatenation (Issue #9)

All changes maintain backward compatibility and pass existing tests.

* feat(sim): add L40S GPU and FP8 compute support

- Add L40S hardware configuration (362.05 TFLOPS, 48GB, 0.864 TB/s)
- Add TFlopsFP8 field to HardwareCalib for native FP8 tensor core support
- Update H100 with TFlopsFP8=1979.0 (2× FP16 rate) and adjusted MFU values
- Update A100-SXM and A100-80 with TFlopsFP8=0 (no native FP8 support)
- Implement FP8 compute selection in roofline model based on weight precision
- Add comprehensive tests for FP8 compute selection logic

Fixes inference-sim#762

Co-Authored-By: Claude <[email protected]>

* docs: add MFU justification and validation tests

- Add inline documentation to hardware_config.json linking to Discussion inference-sim#589
- Add comprehensive MFU validation tests in sim/config_test.go
  - Validates MFU ranges (0 < MFU < 1)
  - Validates MfuDecode < MfuPrefill relationship
  - Tests all GPU types (H100, A100, L40S)
- Update docs/reference/models.md with MFU calibration info box
- All tests pass

Addresses review findings from quick-review

* feat(latency): add TFlopsFP8 validation (R3)

Add validation for HardwareCalib.TFlopsFP8 in ValidateRooflineConfig,
following the same optional-field pattern as MemoryGiB: check if non-zero,
then reject NaN/Inf/negative values.

Includes test coverage for NaN and negative TFlopsFP8 cases.

* fix: address review nits

- roofline.go:217: Fix comment wording from 'upcasted' to 'dequantized to FP16 during GEMM'
- hardware_config.json:8: Restore H100 mfuDecode to 0.30 for consistency with other entries

* docs(roofline): clarify FP8 compute rate selection logic

Improve comment to explicitly document that == 1.0 is intentional:
- FP8 models (exactly 1.0 byte/param) use FP8 compute rate on H100
- Sub-FP8 formats (e.g., W4A16 at 0.5 bytes/param) dequantize to FP16 during GEMM

This addresses the review comment about == 1.0 exact equality. The behavior
is correct: only true FP8 models use FP8 tensor cores. W4A16 and other
sub-FP8 formats use FP16 compute after dequantization, as validated by
TestRooflineStepTime_FP8ComputeSelection_EdgeCases.

---------

Co-authored-by: Claude Opus 4.6 <[email protected]>
susiejojo added a commit that referenced this pull request Mar 20, 2026
- Add inference-sim binary to .gitignore
- Replace hardcoded 0.9 with gpuMemoryUtilization variable in cmd/replay.go
- Add validation guard for gpuMemoryUtilization in cmd/replay.go
- Add logrus.Info logs showing gpu-memory-utilization value in both runCmd and replayCmd
- Update flag description to specify range (0, 1.0]
- Rename test cases: 'below range' -> 'zero is invalid', 'above range' -> 'above 1.0 is invalid'
- Remove TFlopsFP8 validation block from sim/latency/config.go (belongs to PR #765)
- Remove TFlopsFP8 test functions from sim/latency/config_test.go
- Add invariant test TestCalculateKVBlocks_GpuMemoryUtilization_HigherUtilProducesMoreBlocks
- Add gpuMemoryUtilization parameter to CalculateKVBlocks doc comment

All tests pass.
susiejojo added a commit that referenced this pull request Mar 20, 2026
- Add inference-sim binary to .gitignore
- Replace hardcoded 0.9 with gpuMemoryUtilization variable in cmd/replay.go
- Add validation guard for gpuMemoryUtilization in cmd/replay.go
- Add logrus.Info logs showing gpu-memory-utilization value in both runCmd and replayCmd
- Update flag description to specify range (0, 1.0]
- Rename test cases: 'below range' -> 'zero is invalid', 'above range' -> 'above 1.0 is invalid'
- Add invariant test TestCalculateKVBlocks_GpuMemoryUtilization_HigherUtilProducesMoreBlocks
- Add gpuMemoryUtilization parameter to CalculateKVBlocks doc comment
- Revert sim/latency/config.go and config_test.go to match main (TFlopsFP8 changes belong to PR #765)

All tests pass.
susiejojo added a commit that referenced this pull request Mar 20, 2026
- Add inference-sim binary to .gitignore
- Remove inference-sim binary from git tracking
- Replace hardcoded 0.9 with gpuMemoryUtilization variable in cmd/replay.go
- Add validation guard for gpuMemoryUtilization in cmd/replay.go
- Add logrus.Info logs showing gpu-memory-utilization value in both runCmd and replayCmd
- Update flag description to specify range (0, 1.0]
- Rename test cases: 'below range' -> 'zero is invalid', 'above range' -> 'above 1.0 is invalid'
- Add invariant test TestCalculateKVBlocks_GpuMemoryUtilization_HigherUtilProducesMoreBlocks
- Add gpuMemoryUtilization parameter to CalculateKVBlocks doc comment
- Revert sim/latency/config.go and config_test.go to match main (TFlopsFP8 changes belong to PR #765)

All tests pass.
@susiejojo susiejojo deleted the pr762-fp8-hardware-support branch March 20, 2026 18:17
sriumcp pushed a commit that referenced this pull request Mar 20, 2026
* feat(sim): add GpuMemoryUtilization field to KVCacheConfig (BC-1, BC-2)

- Add GpuMemoryUtilization *float64 field to KVCacheConfig struct
- Update NewKVCacheConfig constructor with validation (0.5-1.0 range, NaN/Inf guards)
- Update all 92 construction sites to pass nil (preserves current 0.9 default)
- Add tests for validation and nil handling

Implements BC-1: GpuMemoryUtilization field accepts valid values (0.5-1.0)
Implements BC-2: Constructor validates range and rejects invalid values

* feat(latency): add gpuMemoryUtilization parameter to CalculateKVBlocks (BC-3)

- Add gpuMemoryUtilization parameter to CalculateKVBlocks function
- Remove hardcoded gpuMemUtil constant (0.9)
- Add validation for range [0.5, 1.0] with NaN/Inf guards
- Update all 38 call sites to pass 0.9 (preserves current behavior)
- Add test for parameter validation

Implements BC-3: CalculateKVBlocks accepts gpuMemoryUtilization parameter

* feat(cmd): add --gpu-memory-utilization CLI flag

Implements BC-4: CLI flag with validation and threading to config/latency.

- Added --gpu-memory-utilization flag (default: 0.9, range: 0.5-1.0)
- Added validation with NaN/Inf guards
- Threaded to NewKVCacheConfig and CalculateKVBlocks calls
- All tests pass

* refactor: remove unnecessary GpuMemoryUtilization field from KVCacheConfig

The GpuMemoryUtilization field was only used as an input to CalculateKVBlocks()
for capacity planning, but was never read by the KV cache runtime. This refactor
removes it from KVCacheConfig, keeping it only as a parameter to CalculateKVBlocks().

Changes:
- Removed GpuMemoryUtilization field from KVCacheConfig struct
- Updated NewKVCacheConfig() constructor to remove the parameter
- Updated all call sites (cmd/ and tests) to remove the parameter
- CLI flag --gpu-memory-utilization still works correctly

This separates calculation inputs from runtime configuration, resulting in a
cleaner API and reducing unnecessary parameter passing across 100+ test sites.

* Fix gpu_memory_utilization validation to match vLLM range (0, 1.0]

The original [0.5, 1.0] range was overly restrictive and incompatible with
vLLM's actual validation (gt=0, le=1). This change:

- Updates CalculateKVBlocks validation from [0.5, 1.0] to (0, 1.0]
- Updates CLI validation in cmd/root.go to match
- Updates test cases to verify 0.3 is valid (commonly used in vLLM tests)
- Adds tests for boundary cases (0.0, negative values)

This makes BLIS compatible with valid vLLM configurations using lower
memory utilization values (0.1-0.4) for testing, memory-constrained
scenarios, and multi-instance deployments.

* Revert whitespace changes in batch_formation_test.go

The whitespace alignment changes were unnecessary formatting changes
that should not be part of this PR. Reverting to main branch version.

* fix: address PR #771 review comments

- Add inference-sim binary to .gitignore
- Remove inference-sim binary from git tracking
- Replace hardcoded 0.9 with gpuMemoryUtilization variable in cmd/replay.go
- Add validation guard for gpuMemoryUtilization in cmd/replay.go
- Add logrus.Info logs showing gpu-memory-utilization value in both runCmd and replayCmd
- Update flag description to specify range (0, 1.0]
- Rename test cases: 'below range' -> 'zero is invalid', 'above range' -> 'above 1.0 is invalid'
- Add invariant test TestCalculateKVBlocks_GpuMemoryUtilization_HigherUtilProducesMoreBlocks
- Add gpuMemoryUtilization parameter to CalculateKVBlocks doc comment
- Revert sim/latency/config.go and config_test.go to match main (TFlopsFP8 changes belong to PR #765)

All tests pass.
sriumcp added a commit that referenced this pull request Mar 20, 2026
* feat(infra): Phase 1A — nodes, GPUs, and instance lifecycle

Add node/GPU placement, instance lifecycle management, multi-model
routing, and per-model metrics to the cluster simulator.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* chore: add AGENTS.md to .gitignore

- AGENTS.md is a generated file for agent context
- Should not be committed to the repository

* fix(cluster): prevent double-counting in drain redirect policy

Fixes INV-1 conservation violation when DrainRedirect policy re-injects
queued requests. Previously, redirected requests were counted twice in
CompletedRequests: once when initially injected and again when completed
after redirection.

Changes:
- Add Request.Redirected field to track re-injected requests
- Mark requests as redirected in drainRedirect.Drain() before re-injection
- Skip CompletedRequests increment in recordRequestCompletion() for redirected requests
- Add TestInstanceLifecycle_RedirectDrainPreservesConservation to verify fix

The fix ensures INV-1 (request conservation) holds:
  injected = completed + queued + running + dropped + timed_out

Addresses PR #697 review feedback on drain redirect conservation.

* fix: address PR #697 review comments

- Document DrainPolicy as Phase 1C infrastructure
- Fix warm-up request overcounting by checking warmUpRemaining
- Fix drain callback memory leak in MarkNodeTerminated
- Add named constants for lifecycle event priorities
- Clarify drainWait GPU release and swap-remove logic
- Add .bob/ to .gitignore

* Fix warm-up TTFT penalty implementation

- Initialize warmUpRemaining for all instances in backward-compat mode
- Fix indentation in cluster_event.go
- Update warm-up recording to track first N requests
- Adjust test expectations to account for queueing effects

Fixes build and test failures in PR.

* chore: update .gitignore to ignore .bob/notes instead of entire .bob/ directory

* feat(latency): decouple quantized weight precision from compute dtype (#698)

* feat(latency): decouple quantized weight precision from compute dtype (#443)

Roofline and KV capacity calculations now correctly use quantized weight
precision (e.g. 0.5 bytes/param for W4A16) for weight memory while keeping
the compute dtype (e.g. 2.0 for bfloat16) for KV cache and activations.

- Add WeightBytesPerParam field to ModelConfig with zero-value sentinel
- Parse quantization_config from HuggingFace config.json (GPTQ, AWQ, FP8)
- Add --weight-bytes-per-param CLI flag for manual override
- Update calculateMemoryAccessBytes() and computeModelWeightBytes()
- Add validation in ValidateRooflineConfig
- 18 new tests covering all behavioral contracts

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix(latency): convergence R1 — blackbox path parity, KV validation, quant warnings

Address 3 IMPORTANT findings from convergence review Round 1:

1. Apply --weight-bytes-per-param CLI override in blackbox KV auto-calc
   path (R23: code path parity with analytical backend)
2. Add WeightBytesPerParam validation in CalculateKVBlocks public API
3. Warn when quantization_config is present but weight precision could
   not be auto-detected (both analytical and blackbox paths)

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix(cmd): convergence R2 — early flag validation, backend-specific logs

Move --weight-bytes-per-param validation before backend switch to avoid
Fatalf inside the best-effort blackbox block (preserves fall-through
contract). Make weight precision log backend-specific: roofline uses it
for step time; trained-roofline/crossmodel only for KV capacity.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* style: gofmt struct/var alignment after WeightBytesPerParam addition

Convergence R3: gofmt -w to re-align ModelConfig struct fields and
cmd/root.go var block after longest field name changed.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* style: gofmt const/map alignment in kv_capacity files

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* docs: document MFU calibration approximation for quantized models

Add code comment in rooflineStepTime noting that MFU values were
calibrated against FP16 measurements. For quantized models (W4A16),
reduced weight bandwidth shifts the roofline crossover, producing
conservative estimates — safe for capacity planning.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix(latency): address PR review — FP8 case-insensitive match, test coverage, validation comment

- Use strings.EqualFold for FP8 quant_method matching (case-insensitive)
- Add test for FP8 with bits=8 present (verifies bits-first path agrees)
- Document why WeightBytesPerParam > BytesPerParam is accepted in validation

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* feat(latency): complete three-tier quantized weight detection, remove CLI flag

Add compressed-tensors parsing (config_groups.*.weights.num_bits) to close
the gap where w8a8 models silently fell back to torch_dtype. Add model name
convention detection (w4a16, fp8) as a second-tier fallback. Remove the
--weight-bytes-per-param CLI flag — all three issue #443 options are now
covered by auto-detection, making the manual override unnecessary.

Detection chain: quantization_config → model name → torch_dtype fallback.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix(latency): address PR review — FP8 case-insensitive match, test coverage, validation comment

C1: Extract applyWeightPrecisionFallback shared helper (cmd/hfconfig.go)
    and add model name fallback to cmd/replay.go roofline path (was missing).
    Three call sites (root.go blackbox, root.go roofline, replay.go) now
    share identical fallback + logging logic.

C2: Sort config_groups keys before iteration in compressed-tensors
    parsing (INV-6 determinism).

I2: Add string-to-int coercion for quantization_config.bits field
    (handles "bits": "4" from some HF configs).

I3: Add TestRooflineStepTime_W4A16_LowerThanFP16_MemoryBoundDecode
    end-to-end test verifying quantized model produces lower decode
    step time than FP16 in memory-bound regime.

I4: Add TestValidateRooflineConfig_InfWeightBytesPerParam_ReturnsError
    covering +Inf validation gap.

Minor: Remove double blank line in root.go init().

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* docs: update quantization support language across guides, references, and extension recipes

Five documentation pages still claimed quantization was "not yet modeled" and
recommended blackbox mode, contradicting the three-tier auto-detection merged
in this branch. Addresses PR #698 review comments D1–D5.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix(cmd): warn when trained-roofline ignores quantized weight precision (I4)

Trained-roofline hardcodes FP16 bytesPerElement to match its training
pipeline, so WeightBytesPerParam only affects KV capacity, not step time.
Previously the CLI logged "quantized model detected" without mentioning
this limitation, which was misleading. Now emits an explicit warning in
both run and replay paths.

Addresses review item I4 from PR #698 convergence review.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix: address cosmetic review comments

- Add bitsPerByte constant to replace magic number 8.0 (issue #6)
- Improve roofline approximation comment with quantitative guidance (issue #8)

* Address PR #698 review feedback: refactor quantization parsing and improve code quality

- Extract quantization parsing into parseQuantizationConfig helper (Issue #4)
- Consolidate duplicated trained-roofline warning into warnTrainedRooflineQuantization helper (Issue #1)
- Add validation warning when WeightBytesPerParam > BytesPerParam (Issue #2)
- Add debug logging for malformed compressed-tensors config_groups (Issue #3)
- Add error handling for invalid bits string-to-int coercion (Issue #5)
- Add comment explaining first-match semantics in compressed-tensors parsing (Issue #7)
- Fix inconsistent spacing in string concatenation (Issue #9)

All changes maintain backward compatibility and pass existing tests.

---------

Co-authored-by: Claude Opus 4.6 <[email protected]>

* feat(sim): add L40S GPU and FP8 compute support (#765)

* feat(latency): decouple quantized weight precision from compute dtype (#443)

Roofline and KV capacity calculations now correctly use quantized weight
precision (e.g. 0.5 bytes/param for W4A16) for weight memory while keeping
the compute dtype (e.g. 2.0 for bfloat16) for KV cache and activations.

- Add WeightBytesPerParam field to ModelConfig with zero-value sentinel
- Parse quantization_config from HuggingFace config.json (GPTQ, AWQ, FP8)
- Add --weight-bytes-per-param CLI flag for manual override
- Update calculateMemoryAccessBytes() and computeModelWeightBytes()
- Add validation in ValidateRooflineConfig
- 18 new tests covering all behavioral contracts

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix(latency): convergence R1 — blackbox path parity, KV validation, quant warnings

Address 3 IMPORTANT findings from convergence review Round 1:

1. Apply --weight-bytes-per-param CLI override in blackbox KV auto-calc
   path (R23: code path parity with analytical backend)
2. Add WeightBytesPerParam validation in CalculateKVBlocks public API
3. Warn when quantization_config is present but weight precision could
   not be auto-detected (both analytical and blackbox paths)

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix(cmd): convergence R2 — early flag validation, backend-specific logs

Move --weight-bytes-per-param validation before backend switch to avoid
Fatalf inside the best-effort blackbox block (preserves fall-through
contract). Make weight precision log backend-specific: roofline uses it
for step time; trained-roofline/crossmodel only for KV capacity.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* style: gofmt struct/var alignment after WeightBytesPerParam addition

Convergence R3: gofmt -w to re-align ModelConfig struct fields and
cmd/root.go var block after longest field name changed.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* style: gofmt const/map alignment in kv_capacity files

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* docs: document MFU calibration approximation for quantized models

Add code comment in rooflineStepTime noting that MFU values were
calibrated against FP16 measurements. For quantized models (W4A16),
reduced weight bandwidth shifts the roofline crossover, producing
conservative estimates — safe for capacity planning.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix(latency): address PR review — FP8 case-insensitive match, test coverage, validation comment

- Use strings.EqualFold for FP8 quant_method matching (case-insensitive)
- Add test for FP8 with bits=8 present (verifies bits-first path agrees)
- Document why WeightBytesPerParam > BytesPerParam is accepted in validation

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* feat(latency): complete three-tier quantized weight detection, remove CLI flag

Add compressed-tensors parsing (config_groups.*.weights.num_bits) to close
the gap where w8a8 models silently fell back to torch_dtype. Add model name
convention detection (w4a16, fp8) as a second-tier fallback. Remove the
--weight-bytes-per-param CLI flag — all three issue #443 options are now
covered by auto-detection, making the manual override unnecessary.

Detection chain: quantization_config → model name → torch_dtype fallback.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix(latency): address PR review — FP8 case-insensitive match, test coverage, validation comment

C1: Extract applyWeightPrecisionFallback shared helper (cmd/hfconfig.go)
    and add model name fallback to cmd/replay.go roofline path (was missing).
    Three call sites (root.go blackbox, root.go roofline, replay.go) now
    share identical fallback + logging logic.

C2: Sort config_groups keys before iteration in compressed-tensors
    parsing (INV-6 determinism).

I2: Add string-to-int coercion for quantization_config.bits field
    (handles "bits": "4" from some HF configs).

I3: Add TestRooflineStepTime_W4A16_LowerThanFP16_MemoryBoundDecode
    end-to-end test verifying quantized model produces lower decode
    step time than FP16 in memory-bound regime.

I4: Add TestValidateRooflineConfig_InfWeightBytesPerParam_ReturnsError
    covering +Inf validation gap.

Minor: Remove double blank line in root.go init().

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* docs: update quantization support language across guides, references, and extension recipes

Five documentation pages still claimed quantization was "not yet modeled" and
recommended blackbox mode, contradicting the three-tier auto-detection merged
in this branch. Addresses PR #698 review comments D1–D5.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix(cmd): warn when trained-roofline ignores quantized weight precision (I4)

Trained-roofline hardcodes FP16 bytesPerElement to match its training
pipeline, so WeightBytesPerParam only affects KV capacity, not step time.
Previously the CLI logged "quantized model detected" without mentioning
this limitation, which was misleading. Now emits an explicit warning in
both run and replay paths.

Addresses review item I4 from PR #698 convergence review.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix: address cosmetic review comments

- Add bitsPerByte constant to replace magic number 8.0 (issue #6)
- Improve roofline approximation comment with quantitative guidance (issue #8)

* Address PR #698 review feedback: refactor quantization parsing and improve code quality

- Extract quantization parsing into parseQuantizationConfig helper (Issue #4)
- Consolidate duplicated trained-roofline warning into warnTrainedRooflineQuantization helper (Issue #1)
- Add validation warning when WeightBytesPerParam > BytesPerParam (Issue #2)
- Add debug logging for malformed compressed-tensors config_groups (Issue #3)
- Add error handling for invalid bits string-to-int coercion (Issue #5)
- Add comment explaining first-match semantics in compressed-tensors parsing (Issue #7)
- Fix inconsistent spacing in string concatenation (Issue #9)

All changes maintain backward compatibility and pass existing tests.

* feat(sim): add L40S GPU and FP8 compute support

- Add L40S hardware configuration (362.05 TFLOPS, 48GB, 0.864 TB/s)
- Add TFlopsFP8 field to HardwareCalib for native FP8 tensor core support
- Update H100 with TFlopsFP8=1979.0 (2× FP16 rate) and adjusted MFU values
- Update A100-SXM and A100-80 with TFlopsFP8=0 (no native FP8 support)
- Implement FP8 compute selection in roofline model based on weight precision
- Add comprehensive tests for FP8 compute selection logic

Fixes #762

Co-Authored-By: Claude <[email protected]>

* docs: add MFU justification and validation tests

- Add inline documentation to hardware_config.json linking to Discussion #589
- Add comprehensive MFU validation tests in sim/config_test.go
  - Validates MFU ranges (0 < MFU < 1)
  - Validates MfuDecode < MfuPrefill relationship
  - Tests all GPU types (H100, A100, L40S)
- Update docs/reference/models.md with MFU calibration info box
- All tests pass

Addresses review findings from quick-review

* feat(latency): add TFlopsFP8 validation (R3)

Add validation for HardwareCalib.TFlopsFP8 in ValidateRooflineConfig,
following the same optional-field pattern as MemoryGiB: check if non-zero,
then reject NaN/Inf/negative values.

Includes test coverage for NaN and negative TFlopsFP8 cases.

* fix: address review nits

- roofline.go:217: Fix comment wording from 'upcasted' to 'dequantized to FP16 during GEMM'
- hardware_config.json:8: Restore H100 mfuDecode to 0.30 for consistency with other entries

* docs(roofline): clarify FP8 compute rate selection logic

Improve comment to explicitly document that == 1.0 is intentional:
- FP8 models (exactly 1.0 byte/param) use FP8 compute rate on H100
- Sub-FP8 formats (e.g., W4A16 at 0.5 bytes/param) dequantize to FP16 during GEMM

This addresses the review comment about == 1.0 exact equality. The behavior
is correct: only true FP8 models use FP8 tensor cores. W4A16 and other
sub-FP8 formats use FP16 compute after dequantization, as validated by
TestRooflineStepTime_FP8ComputeSelection_EdgeCases.

---------

Co-authored-by: Claude Opus 4.6 <[email protected]>

* fix(cluster): address sriumcp review — conservation, replay anomaly, non-variadic CollectRawMetrics

- sim/simulator.go: Remove incorrect `if !req.Redirected` guard on CompletedRequests++.
  The guard caused redirected requests to vanish from INV-1 accounting: source's
  InjectedRequests=0 (drained from WaitQ before completion), destination's
  InjectedRequests=0 (skipped CompletedRequests). Destination is the sole
  completion site so incrementing there preserves conservation.

- cmd/replay.go: Add `|| rawMetrics.RoutingRejections > 0` to anomaly condition.
  Clusters where all failures are routing rejections (no routable instances)
  silently omitted the anomaly summary block (I3 from sriumcp review).

- sim/cluster/metrics.go: Make CollectRawMetrics routingRejections parameter
  explicit (non-variadic). Prevents call sites from silently passing 0 and
  missing routing rejections. Updated all test call sites to pass 0 explicitly.

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

* revert(ci): remove skip-cache from golangci-lint step

Unrelated to Phase 1A changes. skip-cache: true was added during
development but should not be merged to main.

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

* fix(cluster): address sriumcp Round 2 — test, stale comment, duplicate Metrics.Requests

- sim/cluster/instance_lifecycle_test.go: Rewrite conservation test to
  actually seed requests into inst0's WaitQ before drain. Previous version
  used a manual event loop on an empty queue — DrainWaitQueue() returned []
  and no redirection ever occurred. New version uses inst0.sim.EnqueueRequest
  directly + empty workload so Run() doesn't push duplicate arrivals. Also
  adds pre/post assertions: QueueDepth==0, inFlightRequests==0, and
  clusterEvents non-empty after drain.

- sim/request.go: Update Redirected field comment to reflect actual behavior.
  Previous comment said "completion accounting is skipped" — opposite of what
  simulator.go:recordRequestCompletion now does.

- sim/cluster/infra_lifecycle_event.go: Delete stale Metrics.Requests entry
  for redirected requests before re-injection. Source registered the request
  at EnqueueRequest time; DrainWaitQueue empties WaitQ but left the entry.
  Destination re-registers on re-enqueue, causing a spurious "duplicate
  request ID" WARN in aggregateMetrics() for every redirected request.

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

* docs: address sriumcp documentation gaps (GAP 1-4)

GAP 1 — configuration.md: Add node_pools and instance_lifecycle YAML
schema to the Policy Bundle section so users can discover and configure
Phase 1A features. Both are YAML-only (no CLI flags). Add a note block
explaining backward compatibility. Update DeploymentConfig row in the
config-to-flag mapping table to note the YAML-only fields.

GAP 2 — results.md Anomaly Counters: Rename "Rejected Requests" to
"Rejected Requests (Admission)" to match actual CLI output label. Add
new "Rejected Requests (Routing)" row explaining when it fires (no
routable instances — all Loading/Draining) and the remediation action.

GAP 3 — results.md Per-Model Metrics: Change mean= to p50= in the
example output block to match printPerModelMetrics which uses m.TTFT.P50.
Add tok/s to the Throughput example line to match actual output format.

GAP 4 — results.md per_model JSON: Add table documenting the per_model
key in --results-path JSON output (omitted when no model tags present),
with field-by-field description.

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

---------

Co-authored-by: tantawi <[email protected]>
Co-authored-by: Claude Opus 4.6 <[email protected]>
Co-authored-by: Dipanwita Guhathakurta <[email protected]>
Co-authored-by: Srinivasan Parthasarathy <[email protected]>
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Extend A100/L40S hardware support for BLIS-roofline + H100-native FP8 compute

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