![]() 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> |
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platform | ||
defconfig | ||
Kconfig | ||
Kconfig.cpu | ||
Kconfig.debug | ||
Kconfig.ide | ||
Makefile | ||
README |
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.