The syncing of filesystems from within the freezer is generally not needed.
Also, if there's an ext3 filesystem loopback-mounted from a FUSE one, the
syncing results in writes to it and deadlocks.  Similarly, it will deadlock if
FUSE implements sync.

Change freeze_processes() so that it doesn't execute sys_sync() and make the
suspend and hibernation code path sync filesystems independently of the
freezer.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NPavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Rename 'struct hibernation_ops' to 'struct platform_hibernation_ops' in
analogy with 'struct platform_suspend_ops'.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NPavel Machek <pavel@ucw.cz>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

During hibernation we also need to tell the ACPI core that we're going to put
the system into the S4 sleep state.  For this reason, an additional method in
'struct hibernation_ops' is needed, playing the role of set_target() in
'struct platform_suspend_operations'.  Moreover, the role of the .prepare()
method is now different, so it's better to introduce another method, that in
general may be different from .prepare(), that will be used to prepare the
platform for creating the hibernation image (.prepare() is used anyway to
notify the platform that we're going to enter the low power state after the
image has been saved).
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The variable suspend_ops representing the set of global platform-specific
suspend-related operations, used by the PM core, need not be exported outside
of kernel/power/main.c .   Make it static.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There is no reason why the .prepare() and .finish() methods in 'struct
platform_suspend_ops' should take any arguments, since architectures don't use
these methods' argument in any practically meaningful way (ie.  either the
target system sleep state is conveyed to the platform by .set_target(), or
there is only one suspend state supported and it is indicated to the PM core
by .valid(), or .prepare() and .finish() aren't defined at all).   There also
is no reason why .finish() should return any result.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NPavel Machek <pavel@ucw.cz>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The name of 'struct pm_ops' suggests that it is related to the power
management in general, but in fact it is only related to suspend.   Moreover,
its name should indicate what this structure is used for, so it seems
reasonable to change it to 'struct platform_suspend_ops'.   In that case, the
name of the global variable of this type used by the PM core and the names of
related functions should be changed accordingly.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NPavel Machek <pavel@ucw.cz>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

suspend_enter() can now become static.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Doh, I completely missed that devices marked DUMMY are not running
the set_mode function. So we force broadcasting, but we keep the
local APIC timer running.

Let the clock event layer mark the device _after_ switching it off.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch contains the following cleanups that are now possible:
- remove the unused security_operations->inode_xattr_getsuffix
- remove the no longer used security_operations->unregister_security
- remove some no longer required exit code
- remove a bunch of no longer used exports
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Acked-by: NJames Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

For those who don't care about CONFIG_SECURITY.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: James Morris <jmorris@namei.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Change migration_call(CPU_DEAD) to use direct spin_lock_irq() instead of
task_rq_lock(rq->idle), rq->idle can't change its task_rq().

This makes the code a bit more symmetrical with migrate_dead_tasks()'s path
which uses spin_lock_irq/spin_unlock_irq.
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Cc: Cliff Wickman <cpw@sgi.com>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently move_task_off_dead_cpu() is called under
write_lock_irq(tasklist).  This means it can't use task_lock() which is
needed to improve migrating to take task's ->cpuset into account.

Change the code to call move_task_off_dead_cpu() with irqs enabled, and
change migrate_live_tasks() to use read_lock(tasklist).

This all is a preparation for the futher changes proposed by Cliff Wickman, see
	http://marc.info/?t=117327786100003Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Cc: Cliff Wickman <cpw@sgi.com>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

load_module() returns zero when mod_sysfs_init() fails, then the module
loading will succeed accidentally.

This patch makes load_module() return error correctly in that case.
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Compiling handle_percpu_irq only on uniprocessor generates an artificial
special case so a typical use like:

  set_irq_chip_and_handler(irq, &some_irq_type, handle_percpu_irq);

needs to be conditionally compiled only on SMP systems as well and an
alternative UP construct is usually needed - for no good reason.

This fixes uniprocessor configurations for some MIPS SMP systems.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Right now futexfs and inotifyfs have one magic 0xBAD1DEA, that looks a
little bit confusing.  Use 0xBAD1DEA as magic for futexfs and 0x2BAD1DEA as
magic for inotifyfs.
Signed-off-by: NAndrey Mirkin <major@openvz.org>
Acked-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The blessed way for standard caches is to use it.  Besides, this may give
this cache a better alignment.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Acked-by: NCedric Le Goater <clg@fr.ibm.com>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

For those who deselect POSIX message queues.

Reduces SLAB size of user_struct from 64 to 32 bytes here, SLUB size -- from
40 bytes to 32 bytes.

[akpm@linux-foundation.org: fix build]
Signed-off-by: NAlexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Save some space because uid_hash_find() has 3 callsites.
Signed-off-by: NAlexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

.. in an effort to make read-only whatever can be made, so that
CONFIG_DEBUG_RODATA can catch as many issues as possible.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

{,un}register_timer_hook() is the API that should be used.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

kernel/sys_ni.c can't #include <linux/syscalls.h> due to cond_syscall(),
but let's tell gcc to not warn with -Wmissing-prototypes.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Kconfig.preempt is not included on some archs (for example, m68k).  On those
archs, the Kconfig machinery complains that KVM selects an undefined symbol
PREEMPT_NOTIFIERS (which lives in Kconfig.preempt).

So move the offending symbol into a Kconfig file which is included by
everyone.

Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NAvi Kivity <avi@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

robust_list, compat_robust_list, pi_state_list, pi_state_cache are
really used if futexes are on.
Signed-off-by: NAlexey Dobriyan <adobriyan@sw.ru>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a prefix "VMCOREINFO_" to the vmcoreinfo macros.  Old vmcoreinfo macros
were defined as generic names SYMBOL/SIZE/OFFSET /LENGTH/CONFIG, and it is
impossible to grep for them.  So these names should be changed.  This
discussion is the following:
http://www.ussg.iu.edu/hypermail/linux/kernel/0709.1/0415.htmlSigned-off-by: NKen'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

[2/3] Add nodemask_t's size and NR_FREE_PAGES's value to vmcoreinfo_data.
  The dump filetering command 'makedumpfile'(v1.1.6 or before) had assumed
  the above values, and it was not good from the reliability viewpoint.
  So makedumpfile v1.2.0 came to need these values and I created the patch
  to let the kernel output them.
  makedumpfile site:
  https://sourceforge.net/projects/makedumpfile/Signed-off-by: NKen'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

[1/3] Cleanup the coding style according to Andrew's comments:
http://lists.infradead.org/pipermail/kexec/2007-August/000522.html
- vmcoreinfo_append_str() should have suitable __attribute__s so that
  the compiler can check its use.
- vmcoreinfo_max_size should have size_t.
- Use get_seconds() instead of xtime.tv_sec.
- Use init_uts_ns.name.release instead of UTS_RELEASE.
Signed-off-by: NKen'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch set frees the restriction that makedumpfile users should install a
vmlinux file (including the debugging information) into each system.

makedumpfile command is the dump filtering feature for kdump.  It creates a
small dumpfile by filtering unnecessary pages for the analysis.  To
distinguish unnecessary pages, it needs a vmlinux file including the debugging
information.  These days, the debugging package becomes a huge file, and it is
hard to install it into each system.

To solve the problem, kdump developers discussed it at lkml and kexec-ml.  As
the result, we reached the conclusion that necessary information for dump
filtering (called "vmcoreinfo") should be embedded into the first kernel file
and it should be accessed through /proc/vmcore during the second kernel.
(http://www.uwsg.iu.edu/hypermail/linux/kernel/0707.0/1806.html)

Dan Aloni created the patch set for the above implementation.
(http://www.uwsg.iu.edu/hypermail/linux/kernel/0707.1/1053.html)

And I updated it for multi architectures and memory models.
(http://lists.infradead.org/pipermail/kexec/2007-August/000479.html)
Signed-off-by: NDan Aloni <da-x@monatomic.org>
Signed-off-by: NKen'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
Signed-off-by: NBernhard Walle <bwalle@suse.de>
Signed-off-by: NDaisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

do_sigaction() returns -ERESTARTNOINTR if signal_pending(). The comment says:

	* If there might be a fatal signal pending on multiple
	* threads, make sure we take it before changing the action.

I think this is not needed. We should only worry about SIGNAL_GROUP_EXIT case,
bit it implies a pending SIGKILL which can't be cleared by do_sigaction.

Kill this special case.
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Acked-by: NRoland McGrath <roland@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

de_thread() yields waiting for ->group_leader to be a zombie. This deadlocks
if an rt-prio execer shares the same cpu with ->group_leader. Change the code
to use ->group_exit_task/notify_count mechanics.

This patch certainly uglifies the code, perhaps someone can suggest something
better.
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Repost of http://lkml.org/lkml/2007/8/10/472 made available by request.

The locking used by get_random_bytes() can conflict with the
preempt_disable() and synchronize_sched() form of RCU.  This patch changes
rcutorture's RNG to gather entropy from the new cpu_clock() interface
(relying on interrupts, preemption, daemons, and rcutorture's reader
thread's rock-bottom scheduling priority to provide useful entropy), and
also adds and EXPORT_SYMBOL_GPL() to make that interface available to GPLed
kernel modules such as rcutorture.

Passes several hours of rcutorture.

[ego@in.ibm.com: Use raw_smp_processor_id() in rcu_random()]
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NGautham R Shenoy <ego@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

To avoid lock contention, we distribute the sched_timer calls across the
cpus so they do not trigger at the same instant.  However, I used NR_CPUS,
which can cause needless grouping on small smp systems depending on your
kernel config.  This patch converts to using num_possible_cpus() so we
spread it as evenly as possible on every machine.

Briefly tested w/ NR_CPUS=255 and verified reduced contention.
Signed-off-by: NJohn Stultz <johnstul@us.ibm.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

- remove the no longer required __attribute__((weak)) of xtime_lock
- remove the following no longer used EXPORT_SYMBOL's:
  - xtime
  - xtime_lock
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The child was found on ->children list under tasklist_lock, it must have a
valid ->signal. __exit_signal() both removes the task from parent->children
and clears ->signal "atomically" under write_lock(tasklist).

Remove unneeded checks.
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Acked-by: NRoland McGrath <roland@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Cleanup.  __group_complete_signal() wakes up ->group_exit_task twice.  The
second wakeup's state includes TASK_UNINTERRUPTIBLE, which is not very
appropriate.

Change the code to pass the "correct" argument to signal_wake_up() and kill
now unneeded wake_up_process().
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The "p->exit_signal == -1 && p->ptrace == 0" check and the comment are
bogus.  We already did exactly the same check in eligible_child(), we did
not drop tasklist_lock since then, and both variables need
write_lock(tasklist) to be changed.
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Nowadays thread_group_empty() and next_thread() are simple list operations,
this optimization doesn't make sense: we are doing exactly same check one
line below.
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Acked-by: NRoland McGrath <roland@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

->siglock provides enough protection to iterate over the thread group.
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Acked-by: NRoland McGrath <roland@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Two threads, T1 and T2.  T2 ptraces P, and P is not a child of ptracer's
thread group.  P exits and goes to TASK_ZOMBIE.

T1 does wait_task_zombie(P):

	P->exit_state = TASK_DEAD;
	...
	read_unlock(&tasklist_lock);

					T2 does exit(), takes tasklist,
					forget_original_parent() does
					__ptrace_unlink(P) but doesn't
					call do_notify_parent(P) because
					p->exit_state == EXIT_DEAD.

Now, P is not visible to our process: __ptrace_unlink() removed it from
->children. We should send notification to P->parent and release P if and
only if SIGCHLD is ignored.

And we have 3 bugs:

1. P->parent does do_wait() and gets -ECHILD (P is on ->parent->children,
   but its state is TASK_DEAD).

2. // wait_task_zombie() continues

	if (put_user(...)) {
		// TODO: is this safe?
		p->exit_state = EXIT_ZOMBIE;
		return;
	}

   we return without notification/release, task_struct leaked.

   Solution: ignore -EFAULT and proceed. It is an application's bug if
   we can't fill infop/stat_addr (in case of VM_FAULT_OOM we have much
   more problems).

3. // wait_task_zombie() continues

	if (p->real_parent != p->parent) {
		// Not taken, it was untraced'ed
		...
	}

	release_task(p);

   we released the task which we shouldn't.

   Solution: check ->real_parent != ->parent before, under tasklist_lock,
   but use ptrace_unlink() instead of __ptrace_unlink() to check ->ptrace.

This patch hopefully solves 2 and 3, the 1st bug will be fixed later, we need
some cleanups in forget_original_parent/reparent_thread.

However, the first race is very unlikely and not critical, so I hope it makes
sense to fix 1 and 2 for now.

4. Small cleanup: don't "restore" EXIT_ZOMBIE unless we know we are not going
   to realease the child.
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A zombie must have a valid ->signal, we are going to release it and
__exit_signal() starts with BUG_ON(!sig).
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With or without this patch, multi-threaded init's are not fully supported,
but do_exit() is completely wrong.  This becomes a real problem when we
support pid namespaces.

1. do_exit() panics when the main thread of /sbin/init exits. It should not
   until the whole thread group exits. Move the code below, under the
   "if (group_dead)" check.

   Note: this means that forget_original_parent() can use an already dead
   child_reaper()'s task_struct. This is OK for /sbin/init because

   	- do_wait() from alive sub-thread still can reap a zombie, we iterate
   	  over all sub-thread's ->children lists

   	- do_notify_parent() will wakeup some alive sub-thread because it sends
   	  the group-wide signal

   However, we should remove choose_new_parent()->BUG_ON(reaper->exit_state)
   for this.

2. We are playing games with ->nsproxy->pid_ns. This code is bogus today, and
   it has to be changed anyway when we really support pid namespaces, just
   remove it.
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Roland McGrath <roland@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>