The decode loop releases MLX's pool of freed buffers every 256 generated
tokens, which is also how often the KV cache grows and drops its previous,
smaller buffers. The check fires only when the token count lands exactly on
a multiple of 256. Speculative decoding emits several tokens per round, so
most rounds step over the boundary and the pool is never released. Each
growth at a long context leaves several GB of buffers that no later
allocation can reuse, so the runner's footprint keeps climbing over a long
generation until the system runs out of memory.
We now release the pool whenever a round crosses a multiple of 256 tokens,
which is what a single-token round already did. With qwen3.8:27b-mlx at a
98k-token context on a 128 GB machine, a long speculative generation
previously grew the runner past 90 GB and panicked the kernel; it now stays
flat at 30 GB.
model/base held the Model interface and the architecture registry while
model held weight loading and quant parameters, and every architecture
imported both. create/client was the CLI side of safetensors imports,
with the create command as its only caller, a duplicate of the command's
adapter error, and a name that read like a second API client. The
safetensors show helpers had their own package under x/ although it
already declared package server.
base merges into model, so base.Model and base.Register become
model.Model and model.Register; nothing in the two overlapped. The create
client's two files and their tests join package cmd, and the five names
the command called are no longer exported. The show helpers join the
server package, and the three entry points routes.go calls become
unexported like the helpers around them.
The MLX runner is the only Go inference runner left and is no longer
experimental, so its packages leave x/. The bindings become a top-level
mlx package beside the carried patches in mlx/compat, mirroring how
llama/ holds the llama.cpp integration, and the runner becomes mlxrunner
with the architectures nested under the package they implement.
Subpackages move with their parent unless listed.
x/mlxrunner/mlx mlx
x/internal/mlxthread mlx/mlxthread
x/internal/mlxthreadtest mlx/mlxthread/mlxthreadtest
x/internal/mlxtest mlx/mlxtest
x/quant mlx/quant
mlx/compat/*.patch mlx/compat/mlx-c (MLX patches go in mlx/compat/mlx)
x/mlxrunner mlxrunner
x/models/nn mlxrunner/nn
x/models/<arch> mlxrunner/model/<arch>
x/mlxrunner/imports.go mlxrunner/model/architectures (new package)
x/create create
x/safetensors fs/safetensors
x/tokenizer mlxrunner/tokenizer
Every package keeps its name, so the Go changes are the import path
rewrites the moves force, and the CMake, Dockerfile, CI cache keys, drift
check and Darwin payload script follow the new paths. Four edits are not
paths: the runner's blank architecture imports become the package
mlxrunner/model/architectures, so the list to extend for a new model sits
beside the architecture directories; a depguard rule keeps the two test
harnesses out of non-test code, as the x/internal placement used to; the
CI change filter's two entries for the long-deleted x/imagegen/mlx now
name the bindings' CMake project and the carried patches, so a change to
either builds the payload; and the tokenizer parity test reads its
fixtures from its own testdata instead of walking out of x/.
x/server and x/imagegen/manifest stay for the next two commits.
Jesse Gross