c - 什么是 Rss 信息？不是 Rss xml 提要

Question

在redis源码中找到了“Rss Information”，但我不知道这是什么。

如果我使用带有查询字符串“file rss information”的 Google 搜索，我得到的唯一结果类似于“RSS xml feed”。

这是在源代码中定义的:

size_t zmalloc_get_rss(void) {
   int page = sysconf(_SC_PAGESIZE);
   size_t rss;
   char buf[4096];
   char filename[256];
   int fd, count;
   char *p, *x;

   snprintf(filename,256,"/proc/%d/stat",getpid());
   if ((fd = open(filename,O_RDONLY)) == -1) return 0;
   if (read(fd,buf,4096) <= 0) {
       close(fd);
       return 0;
   }
   close(fd);

   p = buf;
   count = 23; /* RSS is the 24th field in /proc/<pid>/stat */
   while(p && count--) {
       p = strchr(p,' ');
       if (p) p++;
   }
   if (!p) return 0;
   x = strchr(p,' ');
   if (!x) return 0;
   *x = '\0';

   rss = strtoll(p,NULL,10);
   rss *= page;
   return rss;
}

这会获取进程内存吗？我只能猜测。

Answer 1

是的，RSS 的意思是“驻留集大小”。

参见 proc's manual page :

Resident Set Size: number of pages the process has in real memory. This is just the pages which count toward text, data, or stack space. This does not include pages which have not been demand-loaded in, or which are swapped out.