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
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boot
configs	Blackfin arch: disable CONFIG_HW_RANDOM and CONFIG_DAB in defconfig files	2008-10-16 23:54:43 +08:00
include/asm	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/blackfin-2.6	2008-10-16 12:45:08 -07:00
kernel	Blackfin arch: move bfin_addr_dcachable() and friends into the cacheflush header where it belongs	2008-10-16 23:33:53 +08:00
lib	Blackfin arch: Allow ins functions to have a low latency version	2008-08-14 15:12:55 +08:00
mach-bf527	Blackfin arch: fix bug - build kernel failed at head.S when reprogram clock on all platforms	2008-10-16 23:05:28 +08:00
mach-bf533	Blackfin arch: fix bug - build kernel failed at head.S when reprogram clock on all platforms	2008-10-16 23:05:28 +08:00
mach-bf537	Blackfin arch: fix bug - build kernel failed at head.S when reprogram clock on all platforms	2008-10-16 23:05:28 +08:00
mach-bf548	Blackfin arch: fix bug - build kernel failed at head.S when reprogram clock on all platforms	2008-10-16 23:05:28 +08:00
mach-bf561	Blackfin arch: fix bug - build kernel failed at head.S when reprogram clock on all platforms	2008-10-16 23:05:28 +08:00
mach-common	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/blackfin-2.6	2008-10-16 12:45:08 -07:00
mm	Blackfin arch: Use DTEST rather than DMA to poke at L1 SRAM during exception context	2008-10-08 18:03:33 +08:00
oprofile
Kconfig	container freezer: implement freezer cgroup subsystem	2008-10-20 08:52:34 -07:00
Kconfig.debug	Blackfin arch: Add optional verbose debug	2008-10-10 18:13:21 +08:00
Makefile	Blackfin arch: add support for BF52x-0.2, BF533-0.6, and BF54x-0.2	2008-10-09 12:06:27 +08:00