linux/arch/h8300
Matt Helsley dc52ddc0e6 container freezer: implement freezer cgroup subsystem
This patch implements a new freezer subsystem in the control groups
framework.  It provides a way to stop and resume execution of all tasks in
a cgroup by writing in the cgroup filesystem.

The freezer subsystem in the container filesystem defines a file named
freezer.state.  Writing "FROZEN" to the state file will freeze all tasks
in the cgroup.  Subsequently writing "RUNNING" will unfreeze the tasks in
the cgroup.  Reading will return the current state.

* Examples of usage :

   # mkdir /containers/freezer
   # mount -t cgroup -ofreezer freezer  /containers
   # mkdir /containers/0
   # echo $some_pid > /containers/0/tasks

to get status of the freezer subsystem :

   # cat /containers/0/freezer.state
   RUNNING

to freeze all tasks in the container :

   # echo FROZEN > /containers/0/freezer.state
   # cat /containers/0/freezer.state
   FREEZING
   # cat /containers/0/freezer.state
   FROZEN

to unfreeze all tasks in the container :

   # echo RUNNING > /containers/0/freezer.state
   # cat /containers/0/freezer.state
   RUNNING

This is the basic mechanism which should do the right thing for user space
task in a simple scenario.

It's important to note that freezing can be incomplete.  In that case we
return EBUSY.  This means that some tasks in the cgroup are busy doing
something that prevents us from completely freezing the cgroup at this
time.  After EBUSY, the cgroup will remain partially frozen -- reflected
by freezer.state reporting "FREEZING" when read.  The state will remain
"FREEZING" until one of these things happens:

	1) Userspace cancels the freezing operation by writing "RUNNING" to
		the freezer.state file
	2) Userspace retries the freezing operation by writing "FROZEN" to
		the freezer.state file (writing "FREEZING" is not legal
		and returns EIO)
	3) The tasks that blocked the cgroup from entering the "FROZEN"
		state disappear from the cgroup's set of tasks.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: export thaw_process]
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Acked-by: Serge E. Hallyn <serue@us.ibm.com>
Tested-by: Matt Helsley <matthltc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20 08:52:34 -07:00
..
boot inflate: refactor inflate malloc code 2008-07-25 10:53:28 -07:00
include/asm container freezer: add TIF_FREEZE flag to all architectures 2008-10-20 08:52:33 -07:00
kernel h8300: GENERIC_BUG support 2008-10-16 11:21:29 -07:00
lib kbuild: fix AFLAGS use in h8300 and m68knommu 2007-10-15 21:03:59 +02:00
mm h8300: GENERIC_BUG support 2008-10-16 11:21:29 -07:00
platform h8300: update timer handler - delete files 2008-10-16 11:21:29 -07:00
defconfig h8300: defconfig update 2008-02-23 17:12:16 -08:00
Kconfig container freezer: implement freezer cgroup subsystem 2008-10-20 08:52:34 -07:00
Kconfig.cpu h8300: update timer handler - misc update 2008-10-16 11:21:29 -07:00
Kconfig.debug H8300: Typo: "buildin" -> "builtin" 2007-10-20 00:26:06 +02:00
Kconfig.ide Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
Makefile kbuild: enable 'make AFLAGS=...' to add additional options to AS 2007-10-15 21:59:31 +02:00
README Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00

linux-2.6 for H8/300 README
Yoshinori Sato <ysato@users.sourceforge.jp>

* Supported CPU
H8/300H and H8S

* Supported Target
1.simulator of GDB
  require patches.

2.AE 3068/AE 3069
  more information 
  MICROTRONIQUE <http://www.microtronique.com/>
  Akizuki Denshi Tsusho Ltd. <http://www.akizuki.ne.jp> (Japanese Only)

3.H8MAX 
  see http://ip-sol.jp/h8max/ (Japanese Only)

4.EDOSK2674
  see http://www.eu.renesas.com/products/mpumcu/tool/edk/support/edosk2674.html
      http://www.azpower.com/H8-uClinux/

* Toolchain Version
gcc-3.1 or higher and patch
see arch/h8300/tools_patch/README
binutils-2.12 or higher
gdb-5.2 or higher
The environment that can compile a h8300-elf binary is necessary.

* Userland Develop environment
used h8300-elf toolchains.
see http://www.uclinux.org/pub/uClinux/ports/h8/

* A few words of thanks
Porting to H8/300 serieses is support of Information-technology Promotion Agency, Japan.
I thank support.
and All developer/user.