feat(oxidize-c): H100 Hopper throughput autotune - #44
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Jackson57279 merged 8 commits intoSep 18, 2026
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Port the Rust H100 Hopper tier-9 planner into oxidize-c only: append the H100 GPU family, classify nvidia-smi names, and apply paged KV, chunked prefill, and quantization-aware weight plans when --auto detects an H100 with GPU offload. Co-authored-by: factory-droid[bot] <138933559+factory-droid[bot]@users.noreply.github.com>
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This repository does not receive automatic reviews because it has fewer than 10 stars. ⚙️ Run configurationConfiguration used: defaults Review profile: CHILL Plan: Advanced Run ID: 📝 WalkthroughWalkthroughChangesGPU-aware autotune integration
Estimated code review effort: 4 (Complex) | ~60 minutes Sequence Diagram(s)sequenceDiagram
participant CLI
participant Autotune
participant Scheduler
participant OpenAI
CLI->>Autotune: detect CPU/GPU and build plan
Autotune-->>CLI: return OcTuningPlan
CLI->>Scheduler: apply batch and prefill settings
CLI->>OpenAI: apply plan and explicit prefill override
OpenAI->>OpenAI: initialize sessions with plan KV type
OpenAI->>OpenAI: prefill with plan chunk size
Suggested reviewers: Merge Risk: 🟡 Moderate · up to This PR adds opt-in H100 tuning, but the current head can change non-H100 behavior, apply tuning too late to affect model initialization, and silently ignore explicit serve overrides; invalid prefill values, incomplete embedding integration, and incorrect H100 capability reporting add further correctness issues. It is not merge-ready until these behavior mismatches are fixed or explicitly accepted. 🚥 Pre-merge checks | ✅ 4 | ❌ 1❌ Failed checks (1 warning)
✅ Passed checks (4 passed)
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🛠️ Fix failing CI checks 💡
🧪 Generate unit tests (beta)
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Jackson57279
marked this pull request as ready for review
August 29, 2026 01:12
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Actionable comments posted: 7
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Inline comments:
In `@oxidize-c/include/oxidize/openai.h`:
- Around line 96-101: Extend oc_openai_apply_tuning_plan to accept the parsed
KV-type override from oc_cli_run_serve, then update its implementation and all
callers to propagate ctx->kv_type. Apply precedence as explicit CLI override,
then plan->kv_cache, then the existing environment/default selection, ensuring
serve --kv f32 and --kv q8 reach OpenAI sessions.
Apply the same fix in `@oxidize-c/src/cli/main.c` around lines 655 - 664: The
serve-api branch does not apply the parsed KV override.
In `@oxidize-c/src/autotune/autotune.c`:
- Around line 370-392: Restrict automatic GPU layer assignment in
autotune_set_n_gpu_layers to OC_GPU_FAMILY_H100, leaving A100, B200, and other
GPU-family plans at their existing CPU defaults. Apply the guard before the
function modifies p->n_gpu_layers, or invoke the assignment only from the
H100-specific oc_autotune_tier9_hopper path.
In `@oxidize-c/src/cli/args.c`:
- Line 51: The argument parsers oc_cli_parse_args and oc_cli_context_parse must
share a checked uint32 parser for --prefill-chunk-size; validate full numeric
consumption, errno, and uint32_t range, reject negative, non-numeric, partially
numeric, and out-of-range values, and only set consumed_val after successful
validation.
In `@oxidize-c/src/cli/commands.c`:
- Around line 1455-1464: Move the auto-tuning flow involving
oc_autotune_detect_cpu, oc_autotune_fingerprint_gguf, oc_autotune_plan,
oc_autotune_apply, and oc_openai_apply_tuning_plan to before oc_llama_load and
oc_cli_apply_ctx so model and backend decisions take effect during
initialization. Preserve explicit CLI overrides when applying the tuning plan,
and avoid retaining the current post-initialization block.
In `@oxidize-c/src/cluster/gpu_cluster.c`:
- Around line 56-67: Set the H100 entry’s mig_capable field to true in
oxidize-c/src/cluster/gpu_cluster.c lines 56-67, and update the H100 assertions
in oxidize-c/tests/test_gpu_cluster.c lines 55-68 to verify p->mig_capable is
true.
In `@oxidize-c/src/server/openai.c`:
- Line 938: Update the embedding flow around openai_session_init and the
subsequent token-forwarding logic to use oc_llama_prefill with
openai_prefill_chunk(st) instead of calling oc_llama_forward once per token,
then obtain the embedding from the prefill result’s final hidden state.
- Around line 56-60: Update openai_prefill_chunk so a positive explicit
sched.prefill_chunk_size is honored whenever configured, regardless of
st->has_plan or autotuning state; retain the zero fallback for missing state or
unset sizes.
Apply the same fix in `@oxidize-c/src/cli/main.c` around lines 655 - 664: The
serve-api branch ignores the explicit prefill value unless autotune is enabled.
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📒 Files selected for processing (17)
oxidize-c/include/oxidize/autotune.hoxidize-c/include/oxidize/cli_commands.hoxidize-c/include/oxidize/cuda.hoxidize-c/include/oxidize/gpu_cluster.hoxidize-c/include/oxidize/openai.hoxidize-c/include/oxidize/scheduler.hoxidize-c/src/autotune/autotune.coxidize-c/src/cli/args.coxidize-c/src/cli/args.hoxidize-c/src/cli/commands.coxidize-c/src/cli/main.coxidize-c/src/cluster/gpu_cluster.coxidize-c/src/paged/scheduler.coxidize-c/src/server/openai.coxidize-c/tests/test_autotune.coxidize-c/tests/test_cli.coxidize-c/tests/test_gpu_cluster.c
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1 issue found across 17 files
Prompt for AI agents (unresolved issues)
Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.
<file name="oxidize-c/include/oxidize/scheduler.h">
<violation number="1" location="oxidize-c/include/oxidize/scheduler.h:72">
P3: Adding `prefill_chunk_size` to the public `OcSchedConfig` struct changes its size, which is an ABI break for external consumers compiled against the previous header. The struct is exported through the `extern "C"` API header, copied by value into `OcScheduler` and `OcOpenaiState`, so previously built binaries passing this struct across the API boundary read past the old layout.</violation>
</file>
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Re-trigger cubic
Keep Hopper inventory in --print-plan, but do not apply GPU runtime knobs to CPU sessions. Explicit --kv and --prefill-chunk-size win over the plan; non-Hopper --auto no longer forces F32 KV. Require a full VRAM fit before n_gpu_layers, reject malformed prefill/CSV numbers, and prefill embeddings in chunks. Co-authored-by: factory-droid[bot] <138933559+factory-droid[bot]@users.noreply.github.com>
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All reported issues were addressed across 11 files (changes from recent commits).
Reply with feedback, questions, or to request a fix.
Re-trigger cubic
GPT2/GPT-J/GPT-NeoX/Falcon forwards never write last_hidden, so using that buffer returned a zero vector. Prefill still chunks the prompt; the embedding is the residual in sess.x. Co-authored-by: factory-droid[bot] <138933559+factory-droid[bot]@users.noreply.github.com>
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All reported issues were addressed across 11 files (changes from recent commits).
Reply with feedback, questions, or to request a fix.
Re-trigger cubic
Resolve the CLI args conflict by keeping --prefill-chunk-size parsing and master's --threads threads_set tracking. Co-authored-by: dogesman098 <dogesman098@gmail.com>
Share oc_parse_u32 for CLI prefill and nvidia-smi CSV, warn on invalid chunk sizes, mark H100 as MIG-capable, copy last_hidden from GPT-family forwards so embeddings work for both batched llama prefill and GPT fallbacks, and ignore unrecognized --kv values instead of forcing F32. Co-authored-by: dogesman098 <dogesman098@gmail.com>
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All reported issues were addressed across 21 files
Reply with feedback, questions, or to request a fix.
Re-trigger cubic
Move prefill_chunk_size to the end of OcCliContext, classify Q4_1 as W4A16, size offload VRAM from the largest single GPU, and apply the plan's thread/NUMA policy on serve/--serve-api --auto. CUDA prompt prefill stays per-token and logs that Hopper chunked prefill is CPU/OpenAI-only. Co-authored-by: dogesman098 <dogesman098@gmail.com>
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All reported issues were addressed across 7 files (changes from recent commits).
Tip: Review your code locally with the cubic CLI to iterate faster.
Re-trigger cubic
Serve --auto still applies the plan's thread/NUMA pool, but no longer leaves the HTTP launcher pinned as compute worker 0. Generation keeps the pin. OcCliContext layout test now walks every member in declaration order so mid-struct inserts fail. Co-authored-by: dogesman098 <dogesman098@gmail.com>
Workspace CI cargo-deny failed on rustls 0.23.40 (TLS 1.3 handshake messages accepted across encryption-level boundaries). Upgrade rustls and rustls-webpki to the patched releases so the audit can pass. Co-authored-by: dogesman098 <dogesman098@gmail.com>
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September 18, 2026 01:03
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Port of #34 into oxidize-c only (no Rust/Go/Python/C++ changes), plus a workspace
Cargo.lockbump so GitHubCI / Build and testcan pass.What this does
Adds the H100 GPU family and the Hopper throughput autotune tier:
OC_GPU_FAMILY_H100 = 3) so existing B200/A100/RTX enum values stay stable.H100,H100 80GB HBM3, SXM5/PCIe). A plainRTX 6000still does not match.gpu_family == H100andn_gpu_layers > 0. A100/B200/CPU plans are unchanged, including the 192 GiB NUMA rule.512or1024when ctx ≥ 8192),max_decode_batch = 16.kv_turboquant.--autoapplies hugepages, threads, and NUMA to CLI generation,oxidize-c serve, and--serve-api. Hopper GPU knobs (Q8 KV, chunked prefill, decode batch, CUDA-graph flags) apply only when CUDA offload actually initialized.--print-planstill shows the inventory plan.Review follow-up
--kvand--prefill-chunk-sizewin over the plan (including serve without--auto). Unrecognized--kvvalues are ignored instead of forcing F32.--autono longer forces F32 KV overoc_llama_select_kv_type.n_gpu_layersis all-or-nothing: full model must fit in 85% of the largest single GPU's VRAM, because CUDA still uploads every layer onto one device. Inventory buffer is 128 GPUs. Nonzeron_gpu_layersis inventory/TPS for every GPU family; Hopper knobs stay gated on H100.oc_parse_u32for--prefill-chunk-sizeand nvidia-smi CSV: rejects overflow, partial tokens, signs, and leading whitespace. Invalid--prefill-chunk-sizeprints a warning./v1/embeddingsuses chunkedoc_llama_prefilland readssess.last_hidden. GPT-family forwards now populatelast_hiddenfrom the residual (batched llama prefill already did).mig_capableis true (hardware capability);time_slice_replicasstays 1 so throughput still uses the full GPU.max_decode_batchis stored onOcSchedConfig; this port does not invent batched OpenAI decode.prefill_chunk_sizeis append-only on that in-tree struct and onOcCliContext(last field).chunked_prefillis CPU/OpenAI-only. There is no CUDA batched prefill runtime in this port.serve --auto/--serve-api --autoapply the plan's thread/NUMA pool, then restore the launcher thread's affinity so HTTP workers do not inherit compute worker 0's one-CPU pin. Generation keeps the pin (pin_calling_thread=true).OcCliContextlayout test walks every member in declaration order and requiresprefill_chunk_sizeto be last (alignment padding only).Cargo.lock: rustls0.23.40→0.23.45(and rustls-webpki0.103.13→0.103.15) to clear RUSTSEC-2026-0285 soCI / Build and testcargo-deny can pass.Tests
--kv f32wins over Hopper Q8; invalid--kvdoes not override Hopper or auto selection;--prefill-chunk-sizewithout--auto--prefill-chunk-size(including leading whitespace) stays unset and warnsOcCliContextmember offsets are strictly increasing in declaration order;prefill_chunk_sizeis the last fieldMerged
origin/masterto clear the previous conflict.Summary by cubic
Adds H100 Hopper throughput autotune to oxidize-c, scoped to H100 GPUs with offload enabled; A100, B200, and CPU plans are unchanged. Also bumps
rustlsto 0.23.45 to fix RUSTSEC-2026-0285.Key changes
OC_GPU_FAMILY_H100(MIG-capable) and classifiesnvidia-smiproduct names; plain RTX 6000 still does not match.--autoapplies the plan to CLI generation, serve, and OpenAI server; explicit--prefill-chunk-sizeand recognized--kvwin, while unrecognized--kvis ignored.--autoapplies the plan's thread/NUMA policy without pinning the HTTP launcher as compute worker 0. Non-Hopper--autono longer forces F32 KV.--prefill-chunk-sizevalues warn and are rejected; malformed nvidia-smi CSV lines are skipped. Embeddings prefill in chunks and readlast_hidden, now populated from the residualsess.xfor GPT2/GPT-J/GPT-NeoX/Falcon.OcCliContextfield ordering.Written for commit 82549bf. Summary will update on new commits.
Summary by CodeRabbit
New Features
--autointegration to apply tuning during server startup.--prefill-chunk-sizefor configurable prompt processing.Bug Fixes