original_kernel/fs/proc/Kconfig

config PROC_FS
	bool "/proc file system support" if EXPERT
	default y
	help
	  This is a virtual file system providing information about the status
	  of the system. "Virtual" means that it doesn't take up any space on
	  your hard disk: the files are created on the fly by the kernel when
	  you try to access them. Also, you cannot read the files with older
	  version of the program less: you need to use more or cat.

	  It's totally cool; for example, "cat /proc/interrupts" gives
	  information about what the different IRQs are used for at the moment
	  (there is a small number of Interrupt ReQuest lines in your computer
	  that are used by the attached devices to gain the CPU's attention --
	  often a source of trouble if two devices are mistakenly configured
	  to use the same IRQ). The program procinfo to display some
	  information about your system gathered from the /proc file system.

	  Before you can use the /proc file system, it has to be mounted,
	  meaning it has to be given a location in the directory hierarchy.
	  That location should be /proc. A command such as "mount -t proc proc
	  /proc" or the equivalent line in /etc/fstab does the job.

	  The /proc file system is explained in the file
	  <file:Documentation/filesystems/proc.txt> and on the proc(5) manpage
	  ("man 5 proc").

	  This option will enlarge your kernel by about 67 KB. Several
	  programs depend on this, so everyone should say Y here.

config PROC_KCORE
	bool "/proc/kcore support" if !ARM
	depends on PROC_FS && MMU

config PROC_VMCORE
	bool "/proc/vmcore support"
	depends on PROC_FS && CRASH_DUMP
	default y
        help
        Exports the dump image of crashed kernel in ELF format.

config PROC_SYSCTL
	bool "Sysctl support (/proc/sys)" if EXPERT
	depends on PROC_FS
	select SYSCTL
	default y
	---help---
	  The sysctl interface provides a means of dynamically changing
	  certain kernel parameters and variables on the fly without requiring
	  a recompile of the kernel or reboot of the system.  The primary
	  interface is through /proc/sys.  If you say Y here a tree of
	  modifiable sysctl entries will be generated beneath the
          /proc/sys directory. They are explained in the files
	  in <file:Documentation/sysctl/>.  Note that enabling this
	  option will enlarge the kernel by at least 8 KB.

	  As it is generally a good thing, you should say Y here unless
	  building a kernel for install/rescue disks or your system is very
	  limited in memory.

config PROC_PAGE_MONITOR
 	default y
	depends on PROC_FS && MMU
	bool "Enable /proc page monitoring" if EXPERT
 	help
	  Various /proc files exist to monitor process memory utilization:
	  /proc/pid/smaps, /proc/pid/clear_refs, /proc/pid/pagemap,
	  /proc/kpagecount, and /proc/kpageflags. Disabling these
          interfaces will reduce the size of the kernel by approximately 4kb.