This reverts commit 144060fe.

It causes a resume regression for Andi on his Acer Aspire 1830T post
3.1.  The screen just stays black after wakeup.

Also, it really looks like the wrong way to suspend and resume perf
events: I think they should be done as part of the CPU suspend and
resume, rather than as a notifier that does smp_call_function().
Reported-by: NAndi Kleen <andi@firstfloor.org>
Acked-by: NIngo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

While back-porting Johannes Weiner's patch "mm: memcg-aware global
reclaim" for an internal effort, we noticed a significant performance
regression during page-reclaim heavy workloads due to high contention of
the ss->id_lock.  This lock protects idr map, and serializes calls to
idr_get_next() in css_get_next() (which is used during the memcg hierarchy
walk).

Since idr_get_next() is just doing a look up, we need only serialize it
with respect to idr_remove()/idr_get_new().  By making the ss->id_lock a
rwlock, contention is greatly reduced and performance improves.

Tested: cat a 256m file from a ramdisk in a 128m container 50 times on
each core (one file + container per core) in parallel on a NUMA machine.
Result is the time for the test to complete in 1 of the containers.
Both kernels included Johannes' memcg-aware global reclaim patches.

Before rwlock patch: 1710.778s
After rwlock patch: 152.227s
Signed-off-by: NAndrew Bresticker <abrestic@google.com>
Cc: Paul Menage <menage@gmail.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Ying Han <yinghan@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Adding support for poll() in sysctl fs allows userspace to receive
notifications of changes in sysctl entries.  This adds a infrastructure to
allow files in sysctl fs to be pollable and implements it for hostname and
domainname.

[akpm@linux-foundation.org: s/declare/define/ for definitions]
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: Greg KH <gregkh@suse.de>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

{get,put}_mems_allowed() exist so that general kernel code may locklessly
access a task's set of allowable nodes without having the chance that a
concurrent write will cause the nodemask to be empty on configurations
where MAX_NUMNODES > BITS_PER_LONG.

This could incur a significant delay, however, especially in low memory
conditions because the page allocator is blocking and reclaim requires
get_mems_allowed() itself.  It is not atypical to see writes to
cpuset.mems take over 2 seconds to complete, for example.  In low memory
conditions, this is problematic because it's one of the most imporant
times to change cpuset.mems in the first place!

The only way a task's set of allowable nodes may change is through cpusets
by writing to cpuset.mems and when attaching a task to a generic code is
not reading the nodemask with get_mems_allowed() at the same time, and
then clearing all the old nodes.  This prevents the possibility that a
reader will see an empty nodemask at the same time the writer is storing a
new nodemask.

If at least one node remains unchanged, though, it's possible to simply
set all new nodes and then clear all the old nodes.  Changing a task's
nodemask is protected by cgroup_mutex so it's guaranteed that two threads
are not changing the same task's nodemask at the same time, so the
nodemask is guaranteed to be stored before another thread changes it and
determines whether a node remains set or not.
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Cc: Miao Xie <miaox@cn.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Paul Menage <paul@paulmenage.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If a task has exited to the point it has called cgroup_exit() already,
then we can't migrate it to another cgroup anymore.

This can happen when we are attaching a task to a new cgroup between the
call to ->can_attach_task() on subsystems and the migration that is
eventually tried in cgroup_task_migrate().

In this case cgroup_task_migrate() returns -ESRCH and we don't want to
attach the task to the subsystems because the attachment to the new cgroup
itself failed.

Fix this by only calling ->attach_task() on the subsystems if the cgroup
migration succeeded.
Reported-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NBen Blum <bblum@andrew.cmu.edu>
Acked-by: NPaul Menage <paul@paulmenage.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix unstable tasklist locking in cgroup_attach_proc.

According to this thread - https://lkml.org/lkml/2011/7/27/243 - RCU is
not sufficient to guarantee the tasklist is stable w.r.t.  de_thread and
exit.  Taking tasklist_lock for reading, instead of rcu_read_lock, ensures
proper exclusion.
Signed-off-by: NBen Blum <bblum@andrew.cmu.edu>
Acked-by: NPaul Menage <paul@paulmenage.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There is no functional change.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NJesper Nilsson <jesper.nilsson@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently log_prefix is testing that the first character of the log level
and facility is less than '0' and greater than '9' (which is always
false).

Since the code being updated works because strtoul bombs out (endp isn't
updated) and 0 is returned anyway just remove the check and don't change
the behavior of the function.
Signed-off-by: NWilliam Douglas <william.douglas@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently log_prefix is testing that the first character of the log level
and facility is less than '0' and greater than '9' (which is always
false).  It should be testing to see if the character less than '0' or
greater than '9' instead.  This patch makes that change.

The code being changed worked because strtoul bombs out (endp isn't
updated) and 0 is returned anyway.
Signed-off-by: NWilliam Douglas <william.douglas@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We are enabling some power features on medfield.  To test suspend-2-RAM
conveniently, we need turn on/off console_suspend_enabled frequently.

Add a module parameter, so users could change it by:
/sys/module/printk/parameters/console_suspend
Signed-off-by: NYanmin Zhang <yanmin_zhang@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We are enabling some power features on medfield.  To test suspend-2-RAM
conveniently, we need turn on/off ignore_loglevel frequently without
rebooting.

Add a module parameter, so users can change it by:
/sys/module/printk/parameters/ignore_loglevel
Signed-off-by: NYanmin Zhang <yanmin.zhang@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Userspace needs to know the highest valid capability of the running
kernel, which right now cannot reliably be retrieved from the header files
only.  The fact that this value cannot be determined properly right now
creates various problems for libraries compiled on newer header files
which are run on older kernels.  They assume capabilities are available
which actually aren't.  libcap-ng is one example.  And we ran into the
same problem with systemd too.

Now the capability is exported in /proc/sys/kernel/cap_last_cap.

[akpm@linux-foundation.org: make cap_last_cap const, per Ulrich]
Signed-off-by: NDan Ballard <dan@mindstab.net>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Lennart Poettering <lennart@poettering.net>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Ulrich Drepper <drepper@akkadia.org>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix compilation warnings for CONFIG_SYSCTL=n:

fixed compilation warnings in case of disabled CONFIG_SYSCTL
kernel/watchdog.c:483:13: warning: `watchdog_enable_all_cpus' defined but not used
kernel/watchdog.c:500:13: warning: `watchdog_disable_all_cpus' defined but not used

these functions are static and are used only in sysctl handler, so move
them inside #ifdef CONFIG_SYSCTL too
Signed-off-by: NVasily Averin <vvs@sw.ru>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Make stop_machine() safe to call early in boot, before SMP has been set
up, by simply calling the callback function directly if there's only one
CPU online.

[ Fixes from AKPM:
   - add comment
   - local_irq_flags, not save_flags
   - also call hard_irq_disable() for systems which need it

  Tejun suggested using an explicit flag rather than just looking at
  the online cpu count. ]

Cc: Tejun Heo <tj@kernel.org>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Acked-by: NTejun Heo <htejun@gmail.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Some kernel components pin user space memory (infiniband and perf) (by
increasing the page count) and account that memory as "mlocked".

The difference between mlocking and pinning is:

A. mlocked pages are marked with PG_mlocked and are exempt from
   swapping. Page migration may move them around though.
   They are kept on a special LRU list.

B. Pinned pages cannot be moved because something needs to
   directly access physical memory. They may not be on any
   LRU list.

I recently saw an mlockalled process where mm->locked_vm became
bigger than the virtual size of the process (!) because some
memory was accounted for twice:

Once when the page was mlocked and once when the Infiniband
layer increased the refcount because it needt to pin the RDMA
memory.

This patch introduces a separate counter for pinned pages and
accounts them seperately.
Signed-off-by: NChristoph Lameter <cl@linux.com>
Cc: Mike Marciniszyn <infinipath@qlogic.com>
Cc: Roland Dreier <roland@kernel.org>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This removes mm->oom_disable_count entirely since it's unnecessary and
currently buggy.  The counter was intended to be per-process but it's
currently decremented in the exit path for each thread that exits, causing
it to underflow.

The count was originally intended to prevent oom killing threads that
share memory with threads that cannot be killed since it doesn't lead to
future memory freeing.  The counter could be fixed to represent all
threads sharing the same mm, but it's better to remove the count since:

 - it is possible that the OOM_DISABLE thread sharing memory with the
   victim is waiting on that thread to exit and will actually cause
   future memory freeing, and

 - there is no guarantee that a thread is disabled from oom killing just
   because another thread sharing its mm is oom disabled.
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Reported-by: NOleg Nesterov <oleg@redhat.com>
Reviewed-by: NOleg Nesterov <oleg@redhat.com>
Cc: Ying Han <yinghan@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The basic idea behind cross memory attach is to allow MPI programs doing
intra-node communication to do a single copy of the message rather than a
double copy of the message via shared memory.

The following patch attempts to achieve this by allowing a destination
process, given an address and size from a source process, to copy memory
directly from the source process into its own address space via a system
call.  There is also a symmetrical ability to copy from the current
process's address space into a destination process's address space.

- Use of /proc/pid/mem has been considered, but there are issues with
  using it:
  - Does not allow for specifying iovecs for both src and dest, assuming
    preadv or pwritev was implemented either the area read from or
  written to would need to be contiguous.
  - Currently mem_read allows only processes who are currently
  ptrace'ing the target and are still able to ptrace the target to read
  from the target. This check could possibly be moved to the open call,
  but its not clear exactly what race this restriction is stopping
  (reason  appears to have been lost)
  - Having to send the fd of /proc/self/mem via SCM_RIGHTS on unix
  domain socket is a bit ugly from a userspace point of view,
  especially when you may have hundreds if not (eventually) thousands
  of processes  that all need to do this with each other
  - Doesn't allow for some future use of the interface we would like to
  consider adding in the future (see below)
  - Interestingly reading from /proc/pid/mem currently actually
  involves two copies! (But this could be fixed pretty easily)

As mentioned previously use of vmsplice instead was considered, but has
problems.  Since you need the reader and writer working co-operatively if
the pipe is not drained then you block.  Which requires some wrapping to
do non blocking on the send side or polling on the receive.  In all to all
communication it requires ordering otherwise you can deadlock.  And in the
example of many MPI tasks writing to one MPI task vmsplice serialises the
copying.

There are some cases of MPI collectives where even a single copy interface
does not get us the performance gain we could.  For example in an
MPI_Reduce rather than copy the data from the source we would like to
instead use it directly in a mathops (say the reduce is doing a sum) as
this would save us doing a copy.  We don't need to keep a copy of the data
from the source.  I haven't implemented this, but I think this interface
could in the future do all this through the use of the flags - eg could
specify the math operation and type and the kernel rather than just
copying the data would apply the specified operation between the source
and destination and store it in the destination.

Although we don't have a "second user" of the interface (though I've had
some nibbles from people who may be interested in using it for intra
process messaging which is not MPI).  This interface is something which
hardware vendors are already doing for their custom drivers to implement
fast local communication.  And so in addition to this being useful for
OpenMPI it would mean the driver maintainers don't have to fix things up
when the mm changes.

There was some discussion about how much faster a true zero copy would
go. Here's a link back to the email with some testing I did on that:

http://marc.info/?l=linux-mm&m=130105930902915&w=2

There is a basic man page for the proposed interface here:

http://ozlabs.org/~cyeoh/cma/process_vm_readv.txt

This has been implemented for x86 and powerpc, other architecture should
mainly (I think) just need to add syscall numbers for the process_vm_readv
and process_vm_writev. There are 32 bit compatibility versions for
64-bit kernels.

For arch maintainers there are some simple tests to be able to quickly
verify that the syscalls are working correctly here:

http://ozlabs.org/~cyeoh/cma/cma-test-20110718.tgzSigned-off-by: NChris Yeoh <yeohc@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: <linux-man@vger.kernel.org>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Interrupt controllers can have non-zero starting value for h/w irq numbers.
Adding support in irq_domain allows the domain hwirq numbering to match
the interrupt controllers' numbering.

As this makes looping over irqs for a domain more complicated, add loop
iterators to iterate over all hwirqs and irqs for a domain.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Reviewed-by: NJamie Iles <jamie@jamieiles.com>
Tested-by: NThomas Abraham <thomas.abraham@linaro.org>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Acked-by: NThomas Gleixner <tglx@linutronix.de>

Add prototypes and includes for functions used in different modules.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

This patch introduces a mechanism that allows architecture backends to
remove page tables for the crashkernel memory. This can protect the loaded
kdump kernel from being overwritten by broken kernel code.  Two new
functions crash_map_reserved_pages() and crash_unmap_reserved_pages() are
added that can be implemented by architecture code.  The
crash_map_reserved_pages() function is called before and
crash_unmap_reserved_pages() after the crashkernel segments are loaded.  The
functions are also called in crash_shrink_memory() to create/remove page
tables when the crashkernel memory size is reduced.

To support architectures that have large pages this patch also introduces
a new define KEXEC_CRASH_MEM_ALIGN. The crashkernel start and size must
always be aligned with KEXEC_CRASH_MEM_ALIGN.

Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: NVivek Goyal <vgoyal@redhat.com>
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Currently the vmcoreinfo note is only initialized in case of kdump. On s390
it is possible to create kernel dumps with other dump mechanisms than kdump
(e.g. via hypervisor dump or stand-alone dump tools). For those dumps it
would also be desirable to include the vmcoreinfo data. To accomplish this,
with this patch the vmcoreinfo ELF note is always initialized, not only in
case of a (kdump) crash. On s390 we will add an ABI defined pointer at
a well known address to vmcoreinfo so that dump analysis tools are able to
find this information.

In particular on s390 we have a tool named zgetdump. With this tool it is
possible to convert dump formats on the fly using fuse. E.g. you can mount a
s390 stand-alone dump as ELF dump. When this is done, the tool finds the
vmcoreinfo in the stand-alone dump via the well known ABI defined address and
it creates the respective VMCOREINFO ELF note in the output ELF dump. This then
can be used e.g. by makedumpfile for dump filtering.  No more need for a
vmlinux file with debug information.

So this will look like the following:
$ zgetdump --mount standalone.dump -f elf /mnt
$ ls /mnt
  dump.elf
$ readelf -n /mnt/dump.elf
$ ...
  VMCOREINFO            0x00000474      Unknown note type: (0x00000000)
$ makedumpfile -c -d 31 /mnt/dump.elf dump.kdump

Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: NVivek Goyal <vgoyal@redhat.com>
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Currently only the address of the pre-allocated ELF header is passed with
the elfcorehdr= kernel parameter. In order to reserve memory for the header
in the 2nd kernel also the size is required. Current kdump architecture
backends use different methods to do that, e.g. x86 uses the memmap= kernel
parameter. On s390 there is no easy way to transfer this information.
Therefore the elfcorehdr kernel parameter is extended to also pass the size.
This now can also be used as standard mechanism by all future kdump
architecture backends.

The syntax of the kernel parameter is extended as follows:

elfcorehdr=[size[KMG]@]offset[KMG]

This change is backward compatible because elfcorehdr=size is still allowed.
Acked-by: NVivek Goyal <vgoyal@redhat.com>
Acked-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

On s390 there is a different KEXEC_CONTROL_MEMORY_LIMIT for the normal and
the kdump kexec case. Therefore this patch introduces a new macro
KEXEC_CRASH_CONTROL_MEMORY_LIMIT. This is set to
KEXEC_CONTROL_MEMORY_LIMIT for all architectures that do not define
KEXEC_CRASH_CONTROL_MEMORY_LIMIT.
Acked-by: NVivek Goyal <vgoyal@redhat.com>
Acked-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The user may use "foo-bar" for a kernel parameter defined as "foo_bar".
Make sure it works the other way around too.

Apply the equality of dashes and underscores on early_params and __setup
params as well.

The example given in Documentation/kernel-parameters.txt indicates that
this is the intended behaviour.

With the patch the kernel accepts "log-buf-len=1M" as expected.
https://bugzilla.redhat.com/show_bug.cgi?id=744545Signed-off-by: NMichal Schmidt <mschmidt@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (neatened implementations)

Due to post-increment in condition of kmod_loop_msg in __request_module(),
the system log can be spammed by much more than 5 instances of the 'runaway
loop' message if the number of events triggering it makes the kmod_loop_msg
to overflow.

Fix that by making sure we never increment it past the threshold.
Signed-off-by: NJiri Kosina <jkosina@suse.cz>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
CC: stable@kernel.org

Some functions of irq generic-chip is undefined, because
EXPORT_SYMBOL_GPL is not set to these.

ERROR: "irq_setup_generic_chip" [drivers/gpio/gpio-pch.ko] undefined!
ERROR: "irq_alloc_generic_chip" [drivers/gpio/gpio-pch.ko] undefined!
ERROR: "irq_setup_generic_chip" [drivers/gpio/gpio-ml-ioh.ko] undefined!
ERROR: "irq_alloc_generic_chip" [drivers/gpio/gpio-ml-ioh.ko] undefined!

This is revised that EXPORT_SYMBOL_GPL can be added and referred
to in functions.
Signed-off-by: NNobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

There's a lock inversion between the cputimer->lock and rq->lock;
notably the two callchains involved are:

 update_rlimit_cpu()
   sighand->siglock
   set_process_cpu_timer()
     cpu_timer_sample_group()
       thread_group_cputimer()
         cputimer->lock
         thread_group_cputime()
           task_sched_runtime()
             ->pi_lock
             rq->lock

 scheduler_tick()
   rq->lock
   task_tick_fair()
     update_curr()
       account_group_exec()
         cputimer->lock

Where the first one is enabling a CLOCK_PROCESS_CPUTIME_ID timer, and
the second one is keeping up-to-date.

This problem was introduced by e8abccb7 ("posix-cpu-timers: Cure
SMP accounting oddities").

Cure the problem by removing the cputimer->lock and rq->lock nesting,
this leaves concurrent enablers doing duplicate work, but the time
wasted should be on the same order otherwise wasted spinning on the
lock and the greater-than assignment filter should ensure we preserve
monotonicity.
Reported-by: NDave Jones <davej@redhat.com>
Reported-by: NSimon Kirby <sim@hostway.ca>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: stable@kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Link: http://lkml.kernel.org/r/1318928713.21167.4.camel@twinsSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

The size is always valid, but variable-length arrays generate worse code
for no good reason (unless the function happens to be inlined and the
compiler sees the length for the simple constant it is).

Also, there seems to be some code generation problem on POWER, where
Henrik Bakken reports that register r28 can get corrupted under some
subtle circumstances (interrupt happening at the wrong time?).  That all
indicates some seriously broken compiler issues, but since variable
length arrays are bad regardless, there's little point in trying to
chase it down.

"Just don't do that, then".
Reported-by: NHenrik Grindal Bakken <henribak@cisco.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This adds a mechanism to resume selected IRQs during syscore_resume
instead of dpm_resume_noirq.

Under Xen we need to resume IRQs associated with IPIs early enough
that the resched IPI is unmasked and we can therefore schedule
ourselves out of the stop_machine where the suspend/resume takes
place.

This issue was introduced by 676dc3cf "xen: Use IRQF_FORCE_RESUME".
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Jeremy Fitzhardinge <Jeremy.Fitzhardinge@citrix.com>
Cc: xen-devel <xen-devel@lists.xensource.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Link: http://lkml.kernel.org/r/1318713254.11016.52.camel@dagon.hellion.org.uk
Cc: stable@kernel.org (at least to 2.6.32.y)
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Use threads for LZO compression/decompression on hibernate/thaw.
Improve buffering on hibernate/thaw.
Calculate/verify CRC32 of the image pages on hibernate/thaw.

In my testing, this improved write/read speed by a factor of about two.
Signed-off-by: NBojan Smojver <bojan@rexursive.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Static and extern variables in kernel/power/hibernate.c need not be
initialized to 0 explicitly, so remove those initializations.

[rjw: Modified subject, added changelog.]
Signed-off-by: NBarry Song <Baohua.Song@csr.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

TASK_KILLABLE is often used to put tasks to sleep for quite some time.
One of the most common uses is to put tasks to sleep while waiting for
replies from a server on a networked filesystem (such as CIFS or NFS).

Unfortunately, fake_signal_wake_up does not currently wake up tasks
that are sleeping in TASK_KILLABLE state. This means that even if the
code were in place to allow them to freeze while in this sleep, it
wouldn't work anyway.

This patch changes this function to wake tasks in this state as well.
This should be harmless -- if the code doing the sleeping doesn't have
handling to deal with freezer events, it should just go back to sleep.
If it does, then this will allow that code to do the right thing.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Patch "PM / Hibernate: Add resumewait param to support MMC-like
devices as resume file" added the resumewait kernel command line
option.  The present patch adds resumedelay so that
resumewait/delay were analogous to rootwait/delay.

[rjw: Modified the subject and changelog slightly.]
Signed-off-by: NBarry Song <baohua.song@csr.com>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Some devices like MMC are async detected very slow. For example,
drivers/mmc/host/sdhci.c launches a 200ms delayed work to detect
MMC partitions then add disk.

We have wait_for_device_probe() and scsi_complete_async_scans()
before calling swsusp_check(), but it is not enough to wait for MMC.

This patch adds resumewait kernel param just like rootwait so
that we have enough time to wait until MMC is ready. The difference is
that we wait for resume partition whereas rootwait waits for rootfs
partition (which may be on a different device).

This patch will make hibernation support many embedded products
without SCSI devices, but with devices like MMC.

[rjw: Modified the changelog slightly.]
Signed-off-by: NBarry Song <Baohua.Song@csr.com>
Reviewed-by: NValdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Fix a typo in a function name in the kerneldoc comment next to
resume_target_kernel().

[rjw: Changed the subject slightly, added the changelog.]
Signed-off-by: NBarry Song <Baohua.Song@csr.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

There is a problem with the current ordering of hibernate code which
leads to deadlocks in some filesystems' memory shrinkers.  Namely,
some filesystems use freezable kernel threads that are inactive when
the hibernate memory preallocation is carried out.  Those same
filesystems use memory shrinkers that may be triggered by the
hibernate memory preallocation.  If those memory shrinkers wait for
the frozen kernel threads, the hibernate process deadlocks (this
happens with XFS, for one example).

Apparently, it is not technically viable to redesign the filesystems
in question to avoid the situation described above, so the only
possible solution of this issue is to defer the freezing of kernel
threads until the hibernate memory preallocation is done, which is
implemented by this change.

Unfortunately, this requires the memory preallocation to be done
before the "prepare" stage of device freeze, so after this change the
only way drivers can allocate additional memory for their freeze
routines in a clean way is to use PM notifiers.
Reported-by: NChristoph <cr2005@u-club.de>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Introduce the config option CONFIG_VT_CONSOLE_SLEEP in order to cleanup
the #if defined ugliness for the vt suspend support functions. Note that
CONFIG_VT_CONSOLE is already dependant on CONFIG_VT.

The function pm_set_vt_switch is actually dependant on CONFIG_VT and not
CONFIG_PM_SLEEP. This fixes a compile error when CONFIG_PM_SLEEP is
not set:

drivers/tty/vt/vt_ioctl.c:1794: error: redefinition of 'pm_set_vt_switch'
include/linux/suspend.h:17: error: previous definition of 'pm_set_vt_switch' was here

Also, remove the incorrect path from the comment in console.c.

[rjw: Replaced #if defined() with #ifdef in suspend.h.]
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

In enter_state() we use "state" as an offset for the pm_states[]
array.  The pm_states[] array only has PM_SUSPEND_MAX elements so
this test is off by one.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Cc: stable@kernel.org

For s390 there is one additional byte associated with each page,
the storage key. This byte contains the referenced and changed
bits and needs to be included into the hibernation image.
If the storage keys are not restored to their previous state all
original pages would appear to be dirty. This can cause
inconsistencies e.g. with read-only filesystems.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Suspend statistics should depend on CONFIG_PM_SLEEP, so make that
happen.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>