documentation: update Documentation/filesystem/proc.txt and Documentation/sysctls

Now /proc/sys is described in many places and much information is
redundant.  This patch updates the proc.txt and move the /proc/sys
desciption out to the files in Documentation/sysctls.

Details are:

merge
-  2.1  /proc/sys/fs - File system data
-  2.11 /proc/sys/fs/mqueue - POSIX message queues filesystem
-  2.17 /proc/sys/fs/epoll - Configuration options for the epoll interface
with Documentation/sysctls/fs.txt.

remove
-  2.2  /proc/sys/fs/binfmt_misc - Miscellaneous binary formats
since it's not better then the Documentation/binfmt_misc.txt.

merge
-  2.3  /proc/sys/kernel - general kernel parameters
with Documentation/sysctls/kernel.txt

remove
-  2.5  /proc/sys/dev - Device specific parameters
since it's obsolete the sysfs is used now.

remove
-  2.6  /proc/sys/sunrpc - Remote procedure calls
since it's not better then the Documentation/sysctls/sunrpc.txt

move
-  2.7  /proc/sys/net - Networking stuff
-  2.9  Appletalk
-  2.10 IPX
to newly created Documentation/sysctls/net.txt.

remove
-  2.8  /proc/sys/net/ipv4 - IPV4 settings
since it's not better then the Documentation/networking/ip-sysctl.txt.

add
- Chapter 3 Per-Process Parameters
to descibe /proc/<pid>/xxx parameters.

Signed-off-by: Shen Feng <shen@cn.fujitsu.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/sysctl/00-INDEX

@@ -10,6 +10,8 @@ fs.txt
 	- documentation for /proc/sys/fs/*.
 kernel.txt
 	- documentation for /proc/sys/kernel/*.
+net.txt
+	- documentation for /proc/sys/net/*.
 sunrpc.txt
 	- documentation for /proc/sys/sunrpc/*.
 vm.txt

Documentation/sysctl/fs.txt

@@ -1,5 +1,6 @@
 Documentation for /proc/sys/fs/*	kernel version 2.2.10
 	(c) 1998, 1999,  Rik van Riel <riel@nl.linux.org>
+	(c) 2009,        Shen Feng<shen@cn.fujitsu.com>
 
 For general info and legal blurb, please look in README.
 
@@ -14,7 +15,12 @@ kernel. Since some of the files _can_ be used to screw up your
 system, it is advisable to read both documentation and source
 before actually making adjustments.
 
+1. /proc/sys/fs
+----------------------------------------------------------
+
 Currently, these files are in /proc/sys/fs:
+- aio-max-nr
+- aio-nr
 - dentry-state
 - dquot-max
 - dquot-nr
@@ -30,8 +36,15 @@ Currently, these files are in /proc/sys/fs:
 - super-max
 - super-nr
 
-Documentation for the files in /proc/sys/fs/binfmt_misc is
-in Documentation/binfmt_misc.txt.
+==============================================================
+
+aio-nr & aio-max-nr:
+
+aio-nr is the running total of the number of events specified on the
+io_setup system call for all currently active aio contexts.  If aio-nr
+reaches aio-max-nr then io_setup will fail with EAGAIN.  Note that
+raising aio-max-nr does not result in the pre-allocation or re-sizing
+of any kernel data structures.
 
 ==============================================================
 
@@ -178,3 +191,60 @@ requests.  aio-max-nr allows you to change the maximum value
 aio-nr can grow to.
 
 ==============================================================
+
+
+2. /proc/sys/fs/binfmt_misc
+----------------------------------------------------------
+
+Documentation for the files in /proc/sys/fs/binfmt_misc is
+in Documentation/binfmt_misc.txt.
+
+
+3. /proc/sys/fs/mqueue - POSIX message queues filesystem
+----------------------------------------------------------
+
+The "mqueue"  filesystem provides  the necessary kernel features to enable the
+creation of a  user space  library that  implements  the  POSIX message queues
+API (as noted by the  MSG tag in the  POSIX 1003.1-2001 version  of the System
+Interfaces specification.)
+
+The "mqueue" filesystem contains values for determining/setting  the amount of
+resources used by the file system.
+
+/proc/sys/fs/mqueue/queues_max is a read/write  file for  setting/getting  the
+maximum number of message queues allowed on the system.
+
+/proc/sys/fs/mqueue/msg_max  is  a  read/write file  for  setting/getting  the
+maximum number of messages in a queue value.  In fact it is the limiting value
+for another (user) limit which is set in mq_open invocation. This attribute of
+a queue must be less or equal then msg_max.
+
+/proc/sys/fs/mqueue/msgsize_max is  a read/write  file for setting/getting the
+maximum  message size value (it is every  message queue's attribute set during
+its creation).
+
+
+4. /proc/sys/fs/epoll - Configuration options for the epoll interface
+--------------------------------------------------------
+
+This directory contains configuration options for the epoll(7) interface.
+
+max_user_instances
+------------------
+
+This is the maximum number of epoll file descriptors that a single user can
+have open at a given time. The default value is 128, and should be enough
+for normal users.
+
+max_user_watches
+----------------
+
+Every epoll file descriptor can store a number of files to be monitored
+for event readiness. Each one of these monitored files constitutes a "watch".
+This configuration option sets the maximum number of "watches" that are
+allowed for each user.
+Each "watch" costs roughly 90 bytes on a 32bit kernel, and roughly 160 bytes
+on a 64bit one.
+The current default value for  max_user_watches  is the 1/32 of the available
+low memory, divided for the "watch" cost in bytes.
+

Documentation/sysctl/kernel.txt

@@ -1,5 +1,6 @@
 Documentation for /proc/sys/kernel/*	kernel version 2.2.10
 	(c) 1998, 1999,  Rik van Riel <riel@nl.linux.org>
+	(c) 2009,        Shen Feng<shen@cn.fujitsu.com>
 
 For general info and legal blurb, please look in README.
 
@@ -18,6 +19,7 @@ Currently, these files might (depending on your configuration)
 show up in /proc/sys/kernel:
 - acpi_video_flags
 - acct
+- auto_msgmni
 - core_pattern
 - core_uses_pid
 - ctrl-alt-del
@@ -33,6 +35,7 @@ show up in /proc/sys/kernel:
 - msgmax
 - msgmnb
 - msgmni
+- nmi_watchdog
 - osrelease
 - ostype
 - overflowgid
@@ -40,6 +43,7 @@ show up in /proc/sys/kernel:
 - panic
 - pid_max
 - powersave-nap               [ PPC only ]
+- panic_on_unrecovered_nmi
 - printk
 - randomize_va_space
 - real-root-dev               ==> Documentation/initrd.txt
@@ -55,6 +59,7 @@ show up in /proc/sys/kernel:
 - sysrq                       ==> Documentation/sysrq.txt
 - tainted
 - threads-max
+- unknown_nmi_panic
 - version
 
 ==============================================================
@@ -381,3 +386,51 @@ can be ORed together:
  512 - A kernel warning has occurred.
 1024 - A module from drivers/staging was loaded.
 
+==============================================================
+
+auto_msgmni:
+
+Enables/Disables automatic recomputing of msgmni upon memory add/remove or
+upon ipc namespace creation/removal (see the msgmni description above).
+Echoing "1" into this file enables msgmni automatic recomputing.
+Echoing "0" turns it off.
+auto_msgmni default value is 1.
+
+==============================================================
+
+nmi_watchdog:
+
+Enables/Disables the NMI watchdog on x86 systems.  When the value is non-zero
+the NMI watchdog is enabled and will continuously test all online cpus to
+determine whether or not they are still functioning properly. Currently,
+passing "nmi_watchdog=" parameter at boot time is required for this function
+to work.
+
+If LAPIC NMI watchdog method is in use (nmi_watchdog=2 kernel parameter), the
+NMI watchdog shares registers with oprofile. By disabling the NMI watchdog,
+oprofile may have more registers to utilize.
+
+==============================================================
+
+unknown_nmi_panic:
+
+The value in this file affects behavior of handling NMI. When the value is
+non-zero, unknown NMI is trapped and then panic occurs. At that time, kernel
+debugging information is displayed on console.
+
+NMI switch that most IA32 servers have fires unknown NMI up, for example.
+If a system hangs up, try pressing the NMI switch.
+
+==============================================================
+
+panic_on_unrecovered_nmi:
+
+The default Linux behaviour on an NMI of either memory or unknown is to continue
+operation. For many environments such as scientific computing it is preferable
+that the box is taken out and the error dealt with than an uncorrected
+parity/ECC error get propogated.
+
+A small number of systems do generate NMI's for bizarre random reasons such as
+power management so the default is off. That sysctl works like the existing
+panic controls already in that directory.
+

Documentation/sysctl/net.txt

@@ -0,0 +1,174 @@
+Documentation for /proc/sys/net/*	kernel version 2.4.0-test11-pre4
+	(c) 1999		Terrehon Bowden <terrehon@pacbell.net>
+				Bodo Bauer <bb@ricochet.net>
+	(c) 2000		Jorge Nerin <comandante@zaralinux.com>
+	(c) 2009		Shen Feng <shen@cn.fujitsu.com>
+
+For general info and legal blurb, please look in README.
+
+==============================================================
+
+This file contains the documentation for the sysctl files in
+/proc/sys/net and is valid for Linux kernel version 2.4.0-test11-pre4.
+
+The interface  to  the  networking  parts  of  the  kernel  is  located  in
+/proc/sys/net. The following table shows all possible subdirectories.You may
+see only some of them, depending on your kernel's configuration.
+
+
+Table : Subdirectories in /proc/sys/net
+..............................................................................
+ Directory Content             Directory  Content
+ core      General parameter   appletalk  Appletalk protocol
+ unix      Unix domain sockets netrom     NET/ROM
+ 802       E802 protocol       ax25       AX25
+ ethernet  Ethernet protocol   rose       X.25 PLP layer
+ ipv4      IP version 4        x25        X.25 protocol
+ ipx       IPX                 token-ring IBM token ring
+ bridge    Bridging            decnet     DEC net
+ ipv6      IP version 6
+..............................................................................
+
+1. /proc/sys/net/core - Network core options
+-------------------------------------------------------
+
+rmem_default
+------------
+
+The default setting of the socket receive buffer in bytes.
+
+rmem_max
+--------
+
+The maximum receive socket buffer size in bytes.
+
+wmem_default
+------------
+
+The default setting (in bytes) of the socket send buffer.
+
+wmem_max
+--------
+
+The maximum send socket buffer size in bytes.
+
+message_burst and message_cost
+------------------------------
+
+These parameters  are used to limit the warning messages written to the kernel
+log from  the  networking  code.  They  enforce  a  rate  limit  to  make  a
+denial-of-service attack  impossible. A higher message_cost factor, results in
+fewer messages that will be written. Message_burst controls when messages will
+be dropped.  The  default  settings  limit  warning messages to one every five
+seconds.
+
+warnings
+--------
+
+This controls console messages from the networking stack that can occur because
+of problems on the network like duplicate address or bad checksums. Normally,
+this should be enabled, but if the problem persists the messages can be
+disabled.
+
+netdev_budget
+-------------
+
+Maximum number of packets taken from all interfaces in one polling cycle (NAPI
+poll). In one polling cycle interfaces which are registered to polling are
+probed in a round-robin manner. The limit of packets in one such probe can be
+set per-device via sysfs class/net/<device>/weight .
+
+netdev_max_backlog
+------------------
+
+Maximum number  of  packets,  queued  on  the  INPUT  side, when the interface
+receives packets faster than kernel can process them.
+
+optmem_max
+----------
+
+Maximum ancillary buffer size allowed per socket. Ancillary data is a sequence
+of struct cmsghdr structures with appended data.
+
+2. /proc/sys/net/unix - Parameters for Unix domain sockets
+-------------------------------------------------------
+
+There are  only  two  files  in this subdirectory. They control the delays for
+deleting and destroying socket descriptors.
+
+
+3. /proc/sys/net/ipv4 - IPV4 settings
+-------------------------------------------------------
+Please see: Documentation/networking/ip-sysctl.txt and ipvs-sysctl.txt for
+descriptions of these entries.
+
+
+4. Appletalk
+-------------------------------------------------------
+
+The /proc/sys/net/appletalk  directory  holds the Appletalk configuration data
+when Appletalk is loaded. The configurable parameters are:
+
+aarp-expiry-time
+----------------
+
+The amount  of  time  we keep an ARP entry before expiring it. Used to age out
+old hosts.
+
+aarp-resolve-time
+-----------------
+
+The amount of time we will spend trying to resolve an Appletalk address.
+
+aarp-retransmit-limit
+---------------------
+
+The number of times we will retransmit a query before giving up.
+
+aarp-tick-time
+--------------
+
+Controls the rate at which expires are checked.
+
+The directory  /proc/net/appletalk  holds the list of active Appletalk sockets
+on a machine.
+
+The fields  indicate  the DDP type, the local address (in network:node format)
+the remote  address,  the  size of the transmit pending queue, the size of the
+received queue  (bytes waiting for applications to read) the state and the uid
+owning the socket.
+
+/proc/net/atalk_iface lists  all  the  interfaces  configured for appletalk.It
+shows the  name  of the interface, its Appletalk address, the network range on
+that address  (or  network number for phase 1 networks), and the status of the
+interface.
+
+/proc/net/atalk_route lists  each  known  network  route.  It lists the target
+(network) that the route leads to, the router (may be directly connected), the
+route flags, and the device the route is using.
+
+
+5. IPX
+-------------------------------------------------------
+
+The IPX protocol has no tunable values in proc/sys/net.
+
+The IPX  protocol  does,  however,  provide  proc/net/ipx. This lists each IPX
+socket giving  the  local  and  remote  addresses  in  Novell  format (that is
+network:node:port). In  accordance  with  the  strange  Novell  tradition,
+everything but the port is in hex. Not_Connected is displayed for sockets that
+are not  tied to a specific remote address. The Tx and Rx queue sizes indicate
+the number  of  bytes  pending  for  transmission  and  reception.  The  state
+indicates the  state  the  socket  is  in and the uid is the owning uid of the
+socket.
+
+The /proc/net/ipx_interface  file lists all IPX interfaces. For each interface
+it gives  the network number, the node number, and indicates if the network is
+the primary  network.  It  also  indicates  which  device  it  is bound to (or
+Internal for  internal  networks)  and  the  Frame  Type if appropriate. Linux
+supports 802.3,  802.2,  802.2  SNAP  and DIX (Blue Book) ethernet framing for
+IPX.
+
+The /proc/net/ipx_route  table  holds  a list of IPX routes. For each route it
+gives the  destination  network, the router node (or Directly) and the network
+address of the router (or Connected) for internal networks.