enlarge small buffer to fix common mtu size

common/alloc/buffer_pool.go

@@ -50,11 +50,11 @@ func (p *BufferPool) Free(buffer *Buffer) {
 }
 
 const (
-	SmallBufferSize = 1024 - defaultOffset
+	SmallBufferSize = 1600 - defaultOffset
 	BufferSize      = 8*1024 - defaultOffset
 	LargeBufferSize = 64*1024 - defaultOffset
 )
 
-var smallPool = NewBufferPool(1024, 64)
+var smallPool = NewBufferPool(1600, 128)
 var mediumPool = NewBufferPool(8*1024, 128)
 var largePool = NewBufferPool(64*1024, 64)