Files
ollama/x/mlxrunner/cache/recurrent.go
2026-05-22 17:19:10 +08:00

286 lines
8.2 KiB
Go

package cache
import (
"github.com/ollama/ollama/x/mlxrunner/batch"
"github.com/ollama/ollama/x/mlxrunner/mlx"
"github.com/ollama/ollama/x/models/nn"
)
// Recurrent is the contract for caches that back recurrent linear-attention layers.
type Recurrent interface {
Cache
Get(b *batch.Batch, dtype mlx.DType) *nn.RecurrentHistory
Put(b *batch.Batch, newConv, newDelta *mlx.Array)
}
// RecurrentRecorder records the per-token scan inputs needed to commit an
// accepted prefix after a speculative recurrent forward.
type RecurrentRecorder interface {
Record(qkv, q, k, v, gDecay, beta *mlx.Array)
}
// RecurrentCache stores state for linear-recurrent layers.
//
// Conv state shape: [B, convTail, convDim]
// Delta state shape: [B, numVHeads, headVDim, headKDim]
type RecurrentCache struct {
convState *mlx.Array
deltaState *mlx.Array
offset int
convTail int
convDim int
numVHeads int
headVDim int
headKDim int
}
func (c *RecurrentCache) setState(old, v *mlx.Array, contiguous bool) *mlx.Array {
if v == nil || !v.Valid() {
return old
}
if contiguous {
v = mlx.Contiguous(v, false)
}
v = v.Clone()
mlx.Pin(v)
mlx.Unpin(old)
return v
}
func NewRecurrentCache(convTail, convDim, numVHeads, headVDim, headKDim int32) *RecurrentCache {
return &RecurrentCache{
convTail: int(convTail),
convDim: int(convDim),
numVHeads: int(numVHeads),
headVDim: int(headVDim),
headKDim: int(headKDim),
}
}
func (c *RecurrentCache) ensure(batch int, dtype mlx.DType) {
if batch <= 0 {
batch = 1
}
// Keep the gated-delta recurrent state in float32 even when activations are
// bf16/fp16. The convolution tail stays in the activation dtype.
deltaDType := mlx.DTypeFloat32
needConv := c.convState == nil || !c.convState.Valid() || c.convState.DType() != dtype ||
c.convState.Dim(0) != batch || c.convState.Dim(1) != c.convTail || c.convState.Dim(2) != c.convDim
needDelta := c.deltaState == nil || !c.deltaState.Valid() || c.deltaState.DType() != deltaDType ||
c.deltaState.Dim(0) != batch || c.deltaState.Dim(1) != c.numVHeads || c.deltaState.Dim(2) != c.headVDim || c.deltaState.Dim(3) != c.headKDim
if !needConv && !needDelta {
return
}
if needConv {
c.convState = c.setState(c.convState, mlx.Zeros(dtype, batch, c.convTail, c.convDim), false)
}
if needDelta {
c.deltaState = c.setState(c.deltaState, mlx.Zeros(deltaDType, batch, c.numVHeads, c.headVDim, c.headKDim), false)
}
}
// Get returns the current conv/delta state for the SSM layer's read
// phase. Lazy-initializes zero-filled state tensors using b.InputIDs
// for the batch size; reallocates if the existing state's batch size
// or dtype no longer matches.
func (c *RecurrentCache) Get(b *batch.Batch, dtype mlx.DType) *nn.RecurrentHistory {
c.ensure(b.InputIDs.Dim(0), dtype)
return nn.NewRecurrentHistory(c.convState, c.deltaState)
}
// Put stores the post-computation conv/delta states for the SSM
// layer's write phase and advances the cache offset by the current
// forward's real token count.
//
// Assumes B = 1; heterogeneous batches are not supported.
func (c *RecurrentCache) Put(b *batch.Batch, newConv, newDelta *mlx.Array) {
c.convState = c.setState(c.convState, newConv, true)
c.deltaState = c.setState(c.deltaState, newDelta, false)
c.offset += int(b.SeqQueryLens[0])
}
func (c *RecurrentCache) State() []*mlx.Array {
return []*mlx.Array{c.convState, c.deltaState}
}
// recurrentSnapshot holds paged-out recurrent state. Self-contained —
// does not depend on any parent state.
type recurrentSnapshot struct {
convState, deltaState *mlx.Array
offset int
}
func (s *recurrentSnapshot) Size() int { return s.convState.NumBytes() + s.deltaState.NumBytes() }
func (s *recurrentSnapshot) Close() { mlx.Unpin(s.convState, s.deltaState) }
func (c *RecurrentCache) Snapshot(fromOffset int) Snapshot {
// Recurrent state is not position-sliceable — always snapshot the full state.
if c.convState == nil && c.deltaState == nil {
return nil
}
snap := &recurrentSnapshot{offset: c.offset}
snap.convState = c.convState.Clone()
snap.deltaState = c.deltaState.Clone()
mlx.Pin(snap.convState, snap.deltaState)
return snap
}
func (c *RecurrentCache) Restore(snapshot Snapshot, target int) bool {
if snapshot == nil {
// Recurrent state is cumulative and can't rewind. Only succeed
// if we're already at the target (no-op).
return target == c.offset
}
snap := snapshot.(*recurrentSnapshot)
// Recurrent snapshots encode cumulative state up to exactly
// snap.offset. Target must match — rewinding would leave stale
// state, and advancing isn't possible without feeding tokens.
if target != snap.offset {
return false
}
c.convState = c.setState(c.convState, snap.convState, false)
c.deltaState = c.setState(c.deltaState, snap.deltaState, false)
c.offset = snap.offset
return true
}
func (c *RecurrentCache) Merge(parent, child Snapshot) Snapshot {
// Recurrent snapshots are self-contained — child supersedes parent.
if parent != nil {
parent.Close()
}
return child
}
func (c *RecurrentCache) Split(snapshot Snapshot, at int) (Snapshot, Snapshot) {
// Recurrent state is cumulative and not position-sliceable.
// Cannot recover intermediate state at the split point.
return nil, snapshot
}
func (c *RecurrentCache) Free() {
mlx.Unpin(c.convState, c.deltaState)
c.convState, c.deltaState = nil, nil
c.offset = 0
}
func (c *RecurrentCache) Offset() int { return c.offset }
type speculativeRecurrentCache struct {
speculativeBase
target *RecurrentCache
start int
initialConv *mlx.Array
initialDelta *mlx.Array
qkv, q, k, v, gDecay, beta *mlx.Array
fullConv, fullDelta *mlx.Array
length int
}
func newSpeculativeRecurrentCache(target *RecurrentCache) *speculativeRecurrentCache {
return &speculativeRecurrentCache{
speculativeBase: speculativeBase{offset: target.Offset()},
target: target,
start: target.Offset(),
}
}
func (c *speculativeRecurrentCache) Get(b *batch.Batch, dtype mlx.DType) *nn.RecurrentHistory {
if c.fullConv != nil && c.fullDelta != nil {
return nn.NewRecurrentHistory(c.fullConv, c.fullDelta)
}
history := c.target.Get(b, dtype)
if c.initialConv == nil {
c.initialConv = history.ConvState()
}
if c.initialDelta == nil {
c.initialDelta = history.DeltaState()
}
return history
}
func (c *speculativeRecurrentCache) Record(qkv, q, k, v, gDecay, beta *mlx.Array) {
c.qkv, c.q, c.k, c.v, c.gDecay, c.beta = qkv, q, k, v, gDecay, beta
if qkv != nil {
c.length = qkv.Dim(1)
}
}
func (c *speculativeRecurrentCache) Put(b *batch.Batch, newConv, newDelta *mlx.Array) {
c.fullConv, c.fullDelta = newConv, newDelta
c.offset += int(b.SeqQueryLens[0])
}
func (c *speculativeRecurrentCache) State() []*mlx.Array {
if c.fullConv != nil && c.fullDelta != nil {
return []*mlx.Array{c.fullConv, c.fullDelta}
}
return c.target.State()
}
func (c *speculativeRecurrentCache) commit(n int) {
if n <= 0 {
return
}
if c.length > 0 && n > c.length {
n = c.length
}
if c.length > 0 && n == c.length && c.fullConv != nil && c.fullDelta != nil {
c.target.convState = c.target.setState(c.target.convState, c.fullConv, true)
c.target.deltaState = c.target.setState(c.target.deltaState, c.fullDelta, false)
c.target.offset = c.start + n
return
}
if c.initialConv == nil || c.initialDelta == nil || c.qkv == nil || c.q == nil || c.k == nil || c.v == nil || c.gDecay == nil || c.beta == nil {
return
}
qkv := sliceSeq(c.qkv, n)
convConcat := mlx.Concatenate([]*mlx.Array{c.initialConv, qkv}, 1)
total := convConcat.Dim(1)
nextConv := convConcat.Slice(mlx.Slice(), mlx.Slice(total-c.target.convTail, total), mlx.Slice())
_, delta := mlx.FastGatedDelta(
sliceSeq(c.q, n),
sliceSeq(c.k, n),
sliceSeq(c.v, n),
sliceSeq(c.gDecay, n),
sliceSeq(c.beta, n),
c.initialDelta,
nil,
)
c.target.convState = c.target.setState(c.target.convState, nextConv, true)
c.target.deltaState = c.target.setState(c.target.deltaState, delta, false)
c.target.offset = c.start + n
}
func sliceSeq(a *mlx.Array, n int) *mlx.Array {
switch a.NumDims() {
case 3:
return a.Slice(mlx.Slice(), mlx.Slice(0, n), mlx.Slice())
case 4:
return a.Slice(mlx.Slice(), mlx.Slice(0, n), mlx.Slice(), mlx.Slice())
default:
panic("recurrent speculative sequence tensor must be rank 3 or 4")
}
}