ollama/kvcache/wrapper.go
Jesse Gross dbb149e6f7 ollamarunner: Preallocate worst case graph at startup
Currently, the KV cache and graph are lazily allocated as needed.
The cache is fully allocated on first use of the corresponding
layer whereas the graph grows with the size of the context.

This can be an issue if another application allocates more VRAM
after we do our calculations - Ollama will crash in the middle of
inference. If we instead allocate the maximum needed memory at
startup of the runner, we will either succeed or fail at that point
rather than at some surprising time in the future.

Currently, this only generates a worst case batch for text, which
means that vision models may get a partial allocation and continue
to lazily allocate the rest.
2025-04-08 10:01:28 -07:00

110 lines
2.5 KiB
Go

package kvcache
import (
"math"
"github.com/ollama/ollama/ml"
"github.com/ollama/ollama/model/input"
)
// Wrapper cache is a container for multiple types of caches,
// such as for the encoding and decoding portions of a model.
type WrapperCache struct {
// caches we are wrapping
caches []Cache
// cache to be used for this layer
curType int
}
func NewWrapperCache(caches ...Cache) *WrapperCache {
return &WrapperCache{
caches: caches,
}
}
func (c *WrapperCache) Init(backend ml.Backend, dtype ml.DType, maxSequences, capacity, maxBatch int) {
for _, cache := range c.caches {
cache.Init(backend, dtype, maxSequences, capacity, maxBatch)
}
}
func (c *WrapperCache) SetConfig(config ml.CacheConfig) {
for _, cache := range c.caches {
cache.SetConfig(config)
}
}
func (c *WrapperCache) Close() {
for _, cache := range c.caches {
cache.Close()
}
}
func (c *WrapperCache) StartForward(ctx ml.Context, batch input.Batch, reserve bool) error {
for i, cache := range c.caches {
err := cache.StartForward(ctx, batch, reserve)
if err != nil {
// unwind on error - Remove with endIndex set to math.MaxInt32 does not fail
for j := i - 1; j >= 0; j-- {
for k := range batch.Positions {
_ = c.caches[j].Remove(batch.Sequences[k], batch.Positions[k], math.MaxInt32)
}
}
return err
}
}
c.curType = 0
return nil
}
func (c *WrapperCache) SetLayer(layer int) {
for _, cache := range c.caches {
cache.SetLayer(layer)
}
}
func (c *WrapperCache) SetLayerType(layerType int) {
c.curType = layerType
}
func (c *WrapperCache) UnderlyingCache() Cache {
return c.caches[c.curType]
}
func (c *WrapperCache) Get(ctx ml.Context) (ml.Tensor, ml.Tensor, ml.Tensor) {
return c.caches[c.curType].Get(ctx)
}
func (c *WrapperCache) Put(ctx ml.Context, key, value ml.Tensor) {
c.caches[c.curType].Put(ctx, key, value)
}
func (c *WrapperCache) CopyPrefix(srcSeq, dstSeq int, len int32) {
for _, cache := range c.caches {
cache.CopyPrefix(srcSeq, dstSeq, len)
}
}
func (c *WrapperCache) CanResume(seq int, pos int32) bool {
for _, cache := range c.caches {
if !cache.CanResume(seq, pos) {
return false
}
}
return true
}
func (c *WrapperCache) Remove(seq int, beginIndex, endIndex int32) error {
// If the one of these fails, the caller is supposed to retry with endIndex set to math.MaxInt32, which should not fail
for _, cache := range c.caches {
err := cache.Remove(seq, beginIndex, endIndex)
if err != nil {
return err
}
}
return nil
}