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Fix multi-shard moe-split tensor counting - #4

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michaelneale merged 2 commits into
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codex/fix-moe-split-n-tensors
Apr 17, 2026
Merged

Fix multi-shard moe-split tensor counting#4
michaelneale merged 2 commits into
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codex/fix-moe-split-n-tensors

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@i386

@i386 i386 commented Apr 17, 2026

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This fixes llama-moe-split on the current master branch.

Users building Mesh-LLM's forked llama.cpp can now compile the MoE split tool again instead of failing with an undeclared n_tensors error in the multi-shard write path.

Root Cause

write_group() was updated to operate on input_shards, but the context-size calculation still referenced a single n_tensors variable from the older single-input implementation.

That made the current multi-shard path fail to compile on master.

Change

  • sum gguf_get_n_tensors(...) across all input_shards
  • size the output ggml context from that total tensor count

Validation

  • cmake --build build --target llama-moe-split -j4

@i386
i386 force-pushed the codex/fix-moe-split-n-tensors branch from 4f91049 to 6cd1324 Compare April 17, 2026 08:31
@i386 i386 changed the title [codex] Fix multi-shard moe-split tensor counting Fix multi-shard moe-split tensor counting Apr 17, 2026
@michaelneale
michaelneale marked this pull request as ready for review April 17, 2026 08:45
@michaelneale
michaelneale merged commit ed2adb0 into master Apr 17, 2026
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i386 pushed a commit that referenced this pull request Aug 29, 2026
* Get started with Onyx

* Add architecture

* Skip keys handled in super()

* Loading tensors

* Shorten

* Graph

* Apply suggestion from @pcuenca

* Remove norm now embedding in transformers weights

* Add eot

* Explicit output_multiplier

* Handle post_norm_eps

* No super call; unhardcode eot.

The pattern `self._set_vocab_gpt2()` seems preferred throughout the
codebase, and it allows `set_vocab()` to be called from a different part
of the Python class hierarchy: the drafter model converter that we may
need eventually.

* Register for drafting

* DFlash: inherit rope type from the linked target.

Another option would be to store it in the gguf file itself.

* mmproj conversion

Note: some fields to be renamed after the implementation works. We are
keeping compatibility with the reference Meta gguf for testing purposes.

* "clip" header declarations

* Load mmproj

* Pre-processing

* Graph

* Go back to using delimiters.

Otherwise our generations are worse.

Transformers does not use them. We need to trace inputs to verify
whether they are equivalent.

* downsample_factor -> merge_size

* Add vision graph

lol, forgot from a previous commit

* Additional renames, align with llama.cpp / transformers

* Prefer _size instead of independent _h and _w

* Fix token layout

Co-authored-by: Young Han <younghan@fb.com>

* onyx: bring the chat parser onto the onyx branch

common/chat.cpp on this branch has no Onyx handling, so a converted model
serves malformed chat: the assistant preamble leaks into content
("to=self<|message|>...") and tool calls fail with

    HTTP 500 "The model produced output that does not match the expected
              peg-native format"

common_chat_params_init_onyx exists on onyx-fair-patch, added there by
8bb73dd3d. It was never on this branch, so this is not a regression --
the two lines developed independently.

The code here is taken verbatim from that commit. It is the clean side of
`git merge origin/onyx-fair-patch`: chat.cpp is one of the files that
merges without conflict. The full merge is not viable -- it produces 13
conflicts, including add/add on conversion/onyx.py and src/models/onyx.cpp
where the q_norm-folding and metadata-scale approaches contradict each
other, and #4/#7 are stacked on this branch's side of that.

Verified on this branch: builds with 0 errors, converts an Onyx checkpoint,
and serving it gives "4" for "What is 2+2?" plus a correct
get_weather {"city":"Paris"} tool call, where the unported branch gives the
two failures above.

No converter or runtime changes are included, so this should not interact
with the q_norm work.

Co-authored-by: Beto de Paola <betodepaola@meta.com>

* Less params, bilinear pos-emb interpolation as a graph op instead of CPU

* Map to symbolic V_MMPROJ instead of strings

* Make a couple params explicit

* Patchify via build_inp()

* No param for rope_theta

* Small cleanup

* Restore blank line

* Unpermute, to adapt to the latest transformers checkpoint

* Apply norm after token embeddings

This follows the latest transformers approach.

* Remove duplicated function

* build_vit

* onyx: use the model rope theta on sliding-window layers

* DFlash: conversion from transformers drafter

* Revert rope_type derivation from target

NOTE: this breaks compatibility with Meta's distributed DFlash GGUFs, as
the Q/K are stored in "NEOX" (rotated half) format, like in
transformers.

* Apply suggestion from @pcuenca

* Set model type

* Remove comment that will become obsolete

* Hardcode post_norm_rms_eps instead of new param

* Derive SWA+RoPE pattern from gguf array or scalar

* Fix model type <-> number of layers

* Reorder

* Rename

* Fix typo

* DFlash: seed the draft KV cache from multimodal embedding batches

`common_speculative_impl_draft_dflash::process()` returned early on any batch carrying embeddings, so an image prefill never had its target-layer features fused through the DFlash encoder and injected into the draft's KV cache. That left a hole spanning the image's positions, and the next injection at a post-image position failed to initialize its batch:

```
decoding image batch 1/1, n_tokens_batch = 256
decode: failed to initialize batch
llama_decode: failed to decode, ret = -1
process: llama_decode(ctx_dft) failed rc=-1 (n_tokens=17, offset=0)
srv decode: failed to process speculative batch
```

Every image request with `--spec-type draft-dflash` failed with HTTP 500. Text-only was unaffected, since those batches carry token ids and were let through.

Restore the earlier condition, which admits a batch that is either tokens or embeddings and skips only the degenerate neither/both cases. The rest of `process()` is already layout-agnostic -- it gathers features via `llama_get_embeddings_layer_inp()` and indexes `batch_in.pos[]` / `batch_in.seq_id[]`, none of which assume token ids -- so this is the whole fix.

Validated against `muse-glimmer-30B-bf16.gguf` + `mmproj-muse-glimmer-30B-bf16.gguf` + a DFlash draft head, on an image describe-the-shapes request:

- before: HTTP 500, `failed to process speculative batch`
- after: HTTP 200, draft acceptance 0.34012 (167 accepted / 491 generated), mean len 3.04

Output equivalence holds, which is the property that matters: at temperature 0 the drafted response is byte-identical to the same request served with no draft attached (1213/1213 chars), so the draft is drafting correctly through the image context rather than merely not crashing.

* Conversion: prefer rewrite to mapping

* Revert "Conversion: prefer rewrite to mapping"

This reverts commit a92d0ac.

* fix lint

* sliding_window metadata is not optional

* disable state save/load

* Apply suggestion from @pcuenca

---------

Co-authored-by: Young Han <younghan@fb.com>
Co-authored-by: Beto de Paola <betodepaola@meta.com>
Co-authored-by: Daniel Han <michaelhan2050@gmail.com>
Co-authored-by: ruanrms <ruanslv@gmail.com>
Co-authored-by: Xuan Son Nguyen <son@huggingface.co>
Co-authored-by: Sigbjørn Skjæret <sigbjorn.skjaeret@huggingface.co>
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