cmd/sync: use an independent dynamic sync pool

pkg/sync/sync.go

@@ -29,7 +29,6 @@ import (
 	"sync"
 	"time"
 
-	"github.com/juicedata/juicefs/pkg/chunk"
 	"github.com/juicedata/juicefs/pkg/object"
 	"github.com/juicedata/juicefs/pkg/utils"
 	"github.com/juju/ratelimit"
@@ -558,9 +557,8 @@ func doUploadPart(src, dst object.ObjectStorage, srckey string, off, size int64,
 	}
 	start := time.Now()
 	sz := size
-	p := chunk.NewOffPage(int(size))
-	defer p.Release()
-	data := p.Data
+	data := utils.DynamicAlloc(int(size))
+	defer utils.DynFree(data)
 	var part *object.Part
 	var chksum uint32
 	err := try(3, func() error {

pkg/utils/dynamic_alloc.go

@@ -0,0 +1,51 @@
+/*
+ * JuiceFS, Copyright 2025 Juicedata, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package utils
+
+import (
+	"fmt"
+	"sync"
+)
+
+func DynamicAlloc(size int) []byte {
+	zeros := powerOf2(size)
+	b := *dynPools[zeros].Get().(*[]byte)
+	if cap(b) < size {
+		panic(fmt.Sprintf("%d < %d", cap(b), size))
+	}
+	return b[:size]
+}
+
+func DynFree(b []byte) {
+	dynPools[powerOf2(cap(b))].Put(&b)
+}
+
+var dynPools []*sync.Pool
+
+func init() {
+	dynPools = make([]*sync.Pool, 33) // 1 - 8G
+	for i := 0; i < 33; i++ {
+		func(bits int) {
+			dynPools[i] = &sync.Pool{
+				New: func() interface{} {
+					b := make([]byte, 1<<bits)
+					return &b
+				},
+			}
+		}(i)
+	}
+}