Memory分配
struct之间引用关系
//src/runtime/malloc.go
// fixalloc: a free-list allocator for fixed-size off-heap objects,
// used to manage storage used by the allocator.
// mheap: the malloc heap, managed at page (8192-byte) granularity.
// mspan: a run of in-use pages managed by the mheap.
// mcentral: collects all spans of a given size class.
// mcache: a per-P cache of mspans with free space.
// mstats: allocation statistics.
- fixalloc 用于分配mspan等固定大小的object
- mheap 用于8KB page粒度内存管理
- mspan: 一段连续的pages,用于分配制定specClass的object.
- mcentral: 所有span的list
- mcache: 线程的span cache, 优先从cache中分配, 避免每次访问heap需要lock.
下图摘自1 比较清楚的画出了这几者之间的层级关系
mspan
mspan的创建路径如下
