[RFC] 内存视图增加 glibc 信息

[hyj1991]

// malloc/malloc.h
struct mallinfo
{
  int arena;    /* non-mmapped space allocated from system */
  int ordblks;  /* number of free chunks */
  int smblks;   /* number of fastbin blocks */
  int hblks;    /* number of mmapped regions */
  int hblkhd;   /* space in mmapped regions */
  int usmblks;  /* always 0, preserved for backwards compatibility */
  int fsmblks;  /* space available in freed fastbin blocks */
  int uordblks; /* total allocated space */
  int fordblks; /* total free space */
  int keepcost; /* top-most, releasable (via malloc_trim) space */
};

[hyj1991]

Optional：不使用 glibc malloc 的话没有这部分数据

可以用来快速判断 rss 高但是 heap 低的原因：

• external 低但是 arena 高
  • ordblks 高，基本上就是 top chunk 一直 inuse 导致的问题
  • ordblks 低，基本上可以判断使用了 addon，且不走 v8 binding

[hyj1991]

预计的改动：

• [ ] xprofiler
• [ ] console
• [ ] manager
  • [ ] process table
  • [ ] alarm