alistair23-linux/Documentation/sysctl
Linus Torvalds 496322bc91 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:
 "This is a re-do of the net-next pull request for the current merge
  window.  The only difference from the one I made the other day is that
  this has Eliezer's interface renames and the timeout handling changes
  made based upon your feedback, as well as a few bug fixes that have
  trickeled in.

  Highlights:

   1) Low latency device polling, eliminating the cost of interrupt
      handling and context switches.  Allows direct polling of a network
      device from socket operations, such as recvmsg() and poll().

      Currently ixgbe, mlx4, and bnx2x support this feature.

      Full high level description, performance numbers, and design in
      commit 0a4db187a9 ("Merge branch 'll_poll'")

      From Eliezer Tamir.

   2) With the routing cache removed, ip_check_mc_rcu() gets exercised
      more than ever before in the case where we have lots of multicast
      addresses.  Use a hash table instead of a simple linked list, from
      Eric Dumazet.

   3) Add driver for Atheros CQA98xx 802.11ac wireless devices, from
      Bartosz Markowski, Janusz Dziedzic, Kalle Valo, Marek Kwaczynski,
      Marek Puzyniak, Michal Kazior, and Sujith Manoharan.

   4) Support reporting the TUN device persist flag to userspace, from
      Pavel Emelyanov.

   5) Allow controlling network device VF link state using netlink, from
      Rony Efraim.

   6) Support GRE tunneling in openvswitch, from Pravin B Shelar.

   7) Adjust SOCK_MIN_RCVBUF and SOCK_MIN_SNDBUF for modern times, from
      Daniel Borkmann and Eric Dumazet.

   8) Allow controlling of TCP quickack behavior on a per-route basis,
      from Cong Wang.

   9) Several bug fixes and improvements to vxlan from Stephen
      Hemminger, Pravin B Shelar, and Mike Rapoport.  In particular,
      support receiving on multiple UDP ports.

  10) Major cleanups, particular in the area of debugging and cookie
      lifetime handline, to the SCTP protocol code.  From Daniel
      Borkmann.

  11) Allow packets to cross network namespaces when traversing tunnel
      devices.  From Nicolas Dichtel.

  12) Allow monitoring netlink traffic via AF_PACKET sockets, in a
      manner akin to how we monitor real network traffic via ptype_all.
      From Daniel Borkmann.

  13) Several bug fixes and improvements for the new alx device driver,
      from Johannes Berg.

  14) Fix scalability issues in the netem packet scheduler's time queue,
      by using an rbtree.  From Eric Dumazet.

  15) Several bug fixes in TCP loss recovery handling, from Yuchung
      Cheng.

  16) Add support for GSO segmentation of MPLS packets, from Simon
      Horman.

  17) Make network notifiers have a real data type for the opaque
      pointer that's passed into them.  Use this to properly handle
      network device flag changes in arp_netdev_event().  From Jiri
      Pirko and Timo Teräs.

  18) Convert several drivers over to module_pci_driver(), from Peter
      Huewe.

  19) tcp_fixup_rcvbuf() can loop 500 times over loopback, just use a
      O(1) calculation instead.  From Eric Dumazet.

  20) Support setting of explicit tunnel peer addresses in ipv6, just
      like ipv4.  From Nicolas Dichtel.

  21) Protect x86 BPF JIT against spraying attacks, from Eric Dumazet.

  22) Prevent a single high rate flow from overruning an individual cpu
      during RX packet processing via selective flow shedding.  From
      Willem de Bruijn.

  23) Don't use spinlocks in TCP md5 signing fast paths, from Eric
      Dumazet.

  24) Don't just drop GSO packets which are above the TBF scheduler's
      burst limit, chop them up so they are in-bounds instead.  Also
      from Eric Dumazet.

  25) VLAN offloads are missed when configured on top of a bridge, fix
      from Vlad Yasevich.

  26) Support IPV6 in ping sockets.  From Lorenzo Colitti.

  27) Receive flow steering targets should be updated at poll() time
      too, from David Majnemer.

  28) Fix several corner case regressions in PMTU/redirect handling due
      to the routing cache removal, from Timo Teräs.

  29) We have to be mindful of ipv4 mapped ipv6 sockets in
      upd_v6_push_pending_frames().  From Hannes Frederic Sowa.

  30) Fix L2TP sequence number handling bugs, from James Chapman."

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1214 commits)
  drivers/net: caif: fix wrong rtnl_is_locked() usage
  drivers/net: enic: release rtnl_lock on error-path
  vhost-net: fix use-after-free in vhost_net_flush
  net: mv643xx_eth: do not use port number as platform device id
  net: sctp: confirm route during forward progress
  virtio_net: fix race in RX VQ processing
  virtio: support unlocked queue poll
  net/cadence/macb: fix bug/typo in extracting gem_irq_read_clear bit
  Documentation: Fix references to defunct linux-net@vger.kernel.org
  net/fs: change busy poll time accounting
  net: rename low latency sockets functions to busy poll
  bridge: fix some kernel warning in multicast timer
  sfc: Fix memory leak when discarding scattered packets
  sit: fix tunnel update via netlink
  dt:net:stmmac: Add dt specific phy reset callback support.
  dt:net:stmmac: Add support to dwmac version 3.610 and 3.710
  dt:net:stmmac: Allocate platform data only if its NULL.
  net:stmmac: fix memleak in the open method
  ipv6: rt6_check_neigh should successfully verify neigh if no NUD information are available
  net: ipv6: fix wrong ping_v6_sendmsg return value
  ...
2013-07-09 18:24:39 -07:00
..
00-INDEX sysctl: remove obsolete comments 2011-01-13 08:03:18 -08:00
abi.txt Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
fs.txt Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-08-01 10:26:23 -07:00
kernel.txt perf: Drop sample rate when sampling is too slow 2013-06-23 11:52:57 +02:00
net.txt Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-07-09 18:24:39 -07:00
README Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sunrpc.txt Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
vm.txt mm/page_alloc: fix doc for numa_zonelist_order 2013-07-09 10:33:23 -07:00

Documentation for /proc/sys/		kernel version 2.2.10
	(c) 1998, 1999,  Rik van Riel <riel@nl.linux.org>

'Why', I hear you ask, 'would anyone even _want_ documentation
for them sysctl files? If anybody really needs it, it's all in
the source...'

Well, this documentation is written because some people either
don't know they need to tweak something, or because they don't
have the time or knowledge to read the source code.

Furthermore, the programmers who built sysctl have built it to
be actually used, not just for the fun of programming it :-)

==============================================================

Legal blurb:

As usual, there are two main things to consider:
1. you get what you pay for
2. it's free

The consequences are that I won't guarantee the correctness of
this document, and if you come to me complaining about how you
screwed up your system because of wrong documentation, I won't
feel sorry for you. I might even laugh at you...

But of course, if you _do_ manage to screw up your system using
only the sysctl options used in this file, I'd like to hear of
it. Not only to have a great laugh, but also to make sure that
you're the last RTFMing person to screw up.

In short, e-mail your suggestions, corrections and / or horror
stories to: <riel@nl.linux.org>

Rik van Riel.

==============================================================

Introduction:

Sysctl is a means of configuring certain aspects of the kernel
at run-time, and the /proc/sys/ directory is there so that you
don't even need special tools to do it!
In fact, there are only four things needed to use these config
facilities:
- a running Linux system
- root access
- common sense (this is especially hard to come by these days)
- knowledge of what all those values mean

As a quick 'ls /proc/sys' will show, the directory consists of
several (arch-dependent?) subdirs. Each subdir is mainly about
one part of the kernel, so you can do configuration on a piece
by piece basis, or just some 'thematic frobbing'.

The subdirs are about:
abi/		execution domains & personalities
debug/		<empty>
dev/		device specific information (eg dev/cdrom/info)
fs/		specific filesystems
		filehandle, inode, dentry and quota tuning
		binfmt_misc <Documentation/binfmt_misc.txt>
kernel/		global kernel info / tuning
		miscellaneous stuff
net/		networking stuff, for documentation look in:
		<Documentation/networking/>
proc/		<empty>
sunrpc/		SUN Remote Procedure Call (NFS)
vm/		memory management tuning
		buffer and cache management

These are the subdirs I have on my system. There might be more
or other subdirs in another setup. If you see another dir, I'd
really like to hear about it :-)