container freezer: add TIF_FREEZE flag to all architectures
This patch series introduces a cgroup subsystem that utilizes the swsusp
freezer to freeze a group of tasks. It's immediately useful for batch job
management scripts. It should also be useful in the future for
implementing container checkpoint/restart.
The freezer subsystem in the container filesystem defines a cgroup file
named freezer.state. Reading freezer.state will return the current state
of the cgroup. Writing "FROZEN" to the state file will freeze all tasks
in the cgroup. Subsequently writing "RUNNING" will unfreeze the tasks in
the cgroup.
* 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 patch:
The first step in making the refrigerator() available to all
architectures, even for those without power management.
The purpose of such a change is to be able to use the refrigerator() in a
new control group subsystem which will implement a control group freezer.
[akpm@linux-foundation.org: fix sparc]
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Acked-by: Pavel Machek <pavel@suse.cz>
Acked-by: Serge E. Hallyn <serue@us.ibm.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Nigel Cunningham <nigel@tuxonice.net>
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>
diff --git a/include/asm-m68k/thread_info.h b/include/asm-m68k/thread_info.h
index abc0027..af0fda4 100644
--- a/include/asm-m68k/thread_info.h
+++ b/include/asm-m68k/thread_info.h
@@ -52,5 +52,6 @@
#define TIF_DELAYED_TRACE 14 /* single step a syscall */
#define TIF_SYSCALL_TRACE 15 /* syscall trace active */
#define TIF_MEMDIE 16
+#define TIF_FREEZE 17 /* thread is freezing for suspend */
#endif /* _ASM_M68K_THREAD_INFO_H */
