如何查看当前内核配置？

作者的主页
http://www.it.uc3m.es/~ptb/proconfig/
gentoo加了这个patch，然后
在kernel的配置，file system,

  │ CONFIG_PROC_CONFIG: │
  │ │
  │ This provides a listing in /proc/config of the configuration of │
  │ the compiled kernel. It's useful because people forget or lose │
  │ their notes on how they compiled which kernel image. You can │
  │ then recreate the .config file by │
  │ cat /proc/config > /usr/src/linux/.config │
  │ │
  │ You can compile the code as a module. If compiled in it │
  │ will enlarge your kernel by between 3-16KB. │
  │ │
  │ If unsure, say M.

我是按照module配的
modprobe config
然后就可以 cat /proc/config 了