If DEBUG_SPINLOCK and DEBUG_LOCK_ALLOC are enabled spinlock_t on x86_64
is 72 bytes.  For page->ptl they will be allocated from kmalloc-96 slab,
so we loose 24 on each.  An average system can easily allocate few tens
thousands of page->ptl and overhead is significant.

Let's create a separate slab for page->ptl allocation to solve this.

To make sure that it really works this time, some numbers from my test
machine (just booted, no load):

Before:
  # grep '^\(kmalloc-96\|page->ptl\)' /proc/slabinfo
  kmalloc-96         31987  32190    128   30    1 : tunables  120   60    8 : slabdata   1073   1073     92
After:
  # grep '^\(kmalloc-96\|page->ptl\)' /proc/slabinfo
  page->ptl          27516  28143     72   53    1 : tunables  120   60    8 : slabdata    531    531      9
  kmalloc-96          3853   5280    128   30    1 : tunables  120   60    8 : slabdata    176    176      0

Note that the patch is useful not only for debug case, but also for
PREEMPT_RT, where spinlock_t is always bloated.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This reverts commit ea1e7ed3.

Al points out that while the commit *does* actually create a separate
slab for the page->ptl allocation, that slab is never actually used, and
the code continues to use kmalloc/kfree.

Damien Wyart points out that the original patch did have the conversion
to use kmem_cache_alloc/free, so it got lost somewhere on its way to me.

Revert the half-arsed attempt that didn't do anything.  If we really do
want the special slab (remember: this is all relevant just for debug
builds, so it's not necessarily all that critical) we might as well redo
the patch fully.
Reported-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Kirill A Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If DEBUG_SPINLOCK and DEBUG_LOCK_ALLOC are enabled spinlock_t on x86_64
is 72 bytes.  For page->ptl they will be allocated from kmalloc-96 slab,
so we loose 24 on each.  An average system can easily allocate few tens
thousands of page->ptl and overhead is significant.

Let's create a separate slab for page->ptl allocation to solve this.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch proposes to make init failures more explicit.

Before this, the "No init found" message didn't help much.  It could
sometimes be misleading and actually mean "No *working* init found".

This message could hide many different issues:
 - no init program candidates found at all
 - some init program candidates exist but can't be executed (missing
   execute permissions, failed to load shared libraries, executable
   compiled for an unknown architecture...)

This patch notifies the kernel user when a candidate init program is found
but can't be executed.  In each failure situation, the error code is
displayed, to quickly find the root cause.  "No init found" is also
replaced by "No working init found", which is more correct.

This will help embedded Linux developers (especially the newcomers),
regularly making and debugging new root filesystems.

Credits to Geert Uytterhoeven and Janne Karhunen for their improvement
suggestions.
Signed-off-by: NMichael Opdenacker <michael.opdenacker@free-electrons.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: NJanne Karhunen <Janne.Karhunen@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It's already available in <linux/interrupt.h>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Before commit 026cee00
("params: <level>_initcall-like kernel parameters") the __setup
parameter parsing code could modify parameter in the
static_command_line buffer and such modifications were kept. After
that commit such modifications are destroyed during per-initcall level
parameter parsing because the same static_command_line buffer is used
and only parameters for appropriate initcall level are parsed.

That change broke at least parsing "ubd" parameter in the ubd driver
when the COW file is used.

Now the separate buffer is used for per-initcall parameter parsing.
Signed-off-by: NKrzysztof Mazur <krzysiek@podlesie.net>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Usage of the static key primitives to toggle a branch must not be used
before jump_label_init() is called from init/main.c. jump_label_init
reorganizes and wires up the jump_entries so usage before that could
have unforeseen consequences.

Following primitives are now checked for correct use:
* static_key_slow_inc
* static_key_slow_dec
* static_key_slow_dec_deferred
* jump_label_rate_limit

The x86 architecture already checks this by testing if the default_nop
was already replaced with an optimal nop or with a branch instruction. It
will panic then. Other architectures don't check for this.

Because we need to relax this check for the x86 arch to allow code to
transition from default_nop to the enabled state and other architectures
did not check for this at all this patch introduces checking on the
static_key primitives in a non-arch dependent manner.

All checked functions are considered slow-path so the additional check
does no harm to performance.

The warnings are best observed with earlyprintk.

Based on a patch from Andi Kleen.

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Replace the single preempt_count() 'function' that's an lvalue with
two proper functions:

 preempt_count() - returns the preempt_count value as rvalue
 preempt_count_set() - Allows setting the preempt-count value

Also provide preempt_count_ptr() as a convenience wrapper to implement
all modifying operations.
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-orxrbycjozopqfhb4dxdkdvb@git.kernel.org
[ Fixed build failure. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

The some platforms (e.g., ARM) initializes their clocks as
late_initcalls for some unknown reason.  So make sure
random_int_secret_init() is run after all of the late_initcalls are
run.

Cc: stable@vger.kernel.org
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Prepare for using a static key in the context tracking subsystem.
This will help optimizing the off case on its many users:

* user_enter, user_exit, exception_enter, exception_exit, guest_enter,
  guest_exit, vtime_*()
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Kevin Hilman <khilman@linaro.org>

do_one_initcall() uses a 64 byte string buffer to save a message. This
buffer is declared static and is only used at boot up and when a module
is loaded. As 64 bytes is very small, and this function has very limited
scope, there's no reason to waste permanent memory with this string and
not just simply put it on the stack.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Nothing about the sched_clock implementation in the ARM port is
specific to the architecture. Generalize the code so that other
architectures can use it by selecting GENERIC_SCHED_CLOCK.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
[jstultz: Merge minor collisions with other patches in my tree]
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

The current scheme of using the timer tick was fine for per-thread
events. However, it was causing bias issues in system-wide mode
(including for uncore PMUs). Event groups would not get their fair
share of runtime on the PMU. With tickless kernels, if a core is idle
there is no timer tick, and thus no event rotation (multiplexing).
However, there are events (especially uncore events) which do count
even though cores are asleep.

This patch changes the timer source for multiplexing.  It introduces a
per-PMU per-cpu hrtimer. The advantage is that even when a core goes
idle, it will come back to service the hrtimer, thus multiplexing on
system-wide events works much better.

The per-PMU implementation (suggested by PeterZ) enables adjusting the
multiplexing interval per PMU. The preferred interval is stashed into
the struct pmu. If not set, it will be forced to the default interval
value.

In order to minimize the impact of the hrtimer, it is turned on and
off on demand. When the PMU on a CPU is overcommited, the hrtimer is
activated.  It is stopped when the PMU is not overcommitted.

In order for this to work properly, we had to change the order of
initialization in start_kernel() such that hrtimer_init() is run
before perf_event_init().

The default interval in milliseconds is set to a timer tick just like
with the old code. We will provide a sysctl to tune this in another
patch.
Signed-off-by: NStephane Eranian <eranian@google.com>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: http://lkml.kernel.org/r/1364991694-5876-2-git-send-email-eranian@google.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Commit f91eb62f ("init: scream bloody murder if interrupts are
enabled too early") added three new warnings.  The first two seemed
reasonable, but the third included a warning when an initcall returned
non-zero.  Although, the third WARN() does include an imbalanced preempt
disabled, or irqs disable, it shouldn't warn if it only had an initcall
that just returns non-zero.

In fact, according to Linus, it shouldn't print at all.  As it only
prints with initcall_debug set, and that already shows enough
information to fix things.

Link: http://lkml.kernel.org/r/CA+55aFzaBC5SFi7=F2mfm+KWY5qTsBmOqgbbs8E+LUS8JK-sBg@mail.gmail.comSuggested-by: NLinus Torvalds <torvalds@linux-foundation.org>
Reported-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Also enables cleanup of some 80-col trickery.

Cc: Richard Weinberger <richard@nod.at>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If the kernel was booted with the "quiet" boot option we have currently no
chance to see why an initrd fails.  Change KERN_WARNING to KERN_ERR to see
what is going on.
Signed-off-by: NRichard Weinberger <richard@nod.at>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jim Cromie <jim.cromie@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

As I was testing a lot of my code recently, and having several
"successes", I accidentally noticed in the dmesg this little line:

  start_kernel(): bug: interrupts were enabled *very* early, fixing it

Sure enough, one of my patches two commits ago enabled interrupts early.
The sad part here is that I never noticed it, and I ran several tests with
ktest too, and ktest did not notice this line.

What ktest looks for (and so does many other automated testing scripts) is
a back trace produced by a WARN_ON() or BUG().  As a back trace was never
produced, my buggy patch could have slipped into linux-next, or even
worse, mainline.

Adding a WARN(!irqs_disabled()) makes this bug a little more obvious:

  PID hash table entries: 4096 (order: 3, 32768 bytes)
  __ex_table already sorted, skipping sort
  Checking aperture...
  No AGP bridge found
  Calgary: detecting Calgary via BIOS EBDA area
  Calgary: Unable to locate Rio Grande table in EBDA - bailing!
  Memory: 2003252k/2054848k available (4857k kernel code, 460k absent, 51136k reserved, 6210k data, 1096k init)
  ------------[ cut here ]------------
  WARNING: at /home/rostedt/work/git/linux-trace.git/init/main.c:543 start_kernel+0x21e/0x415()
  Hardware name: To Be Filled By O.E.M.
  Interrupts were enabled *very* early, fixing it
  Modules linked in:
  Pid: 0, comm: swapper/0 Not tainted 3.8.0-test+ #286
  Call Trace:
    warn_slowpath_common+0x83/0x9b
    warn_slowpath_fmt+0x46/0x48
    start_kernel+0x21e/0x415
    x86_64_start_reservations+0x10e/0x112
    x86_64_start_kernel+0x102/0x111
  ---[ end trace 007d8b0491b4f5d8 ]---
  Preemptible hierarchical RCU implementation.
   RCU restricting CPUs from NR_CPUS=8 to nr_cpu_ids=4.
  NR_IRQS:4352 nr_irqs:712 16
  Console: colour VGA+ 80x25
  console [ttyS0] enabled, bootconsole disabled

Do you see it?

The original version of this patch just slapped a WARN_ON() in there and
kept the printk().  Ard van Breemen suggested using the WARN() interface,
which makes the code a bit cleaner.

Also, while examining other warnings in init/main.c, I found two other
locations that deserve a bloody murder scream if their conditions are hit,
and updated them accordingly.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Cc: Ard van Breemen <ard@telegraafnet.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We need full dynticks CPU to also be RCU nocb so
that we don't have to keep the tick to handle RCU
callbacks.

Make sure the range passed to nohz_full= boot
parameter is a subset of rcu_nocbs=

The CPUs that fail to meet this requirement will be
excluded from the nohz_full range. This is checked
early in boot time, before any CPU has the opportunity
to stop its tick.
Suggested-by: NSteven Rostedt <rostedt@goodmis.org>
Reviewed-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>

For now this calls cpu_idle(), but in the long run we want to move the
cpu bringup code to the core and therefor we add a state argument.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: NCc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Link: http://lkml.kernel.org/r/20130321215233.583190032@linutronix.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

To convert the clockevents code to cpumask_var_t we need to move the
init call after the allocator setup. 

Clockevents are earliest registered from time_init() as they need
interrupts being set up, so this is safe.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20130306111537.304379448@linutronix.de
Cc: Rusty Russell <rusty@rustcorp.com.au>

Originally 'efi_enabled' indicated whether a kernel was booted from
EFI firmware. Over time its semantics have changed, and it now
indicates whether or not we are booted on an EFI machine with
bit-native firmware, e.g. 64-bit kernel with 64-bit firmware.

The immediate motivation for this patch is the bug report at,

    https://bugs.launchpad.net/ubuntu-cdimage/+bug/1040557

which details how running a platform driver on an EFI machine that is
designed to run under BIOS can cause the machine to become
bricked. Also, the following report,

    https://bugzilla.kernel.org/show_bug.cgi?id=47121

details how running said driver can also cause Machine Check
Exceptions. Drivers need a new means of detecting whether they're
running on an EFI machine, as sadly the expression,

    if (!efi_enabled)

hasn't been a sufficient condition for quite some time.

Users actually want to query 'efi_enabled' for different reasons -
what they really want access to is the list of available EFI
facilities.

For instance, the x86 reboot code needs to know whether it can invoke
the ResetSystem() function provided by the EFI runtime services, while
the ACPI OSL code wants to know whether the EFI config tables were
mapped successfully. There are also checks in some of the platform
driver code to simply see if they're running on an EFI machine (which
would make it a bad idea to do BIOS-y things).

This patch is a prereq for the samsung-laptop fix patch.

Cc: David Airlie <airlied@linux.ie>
Cc: Corentin Chary <corentincj@iksaif.net>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Peter Jones <pjones@redhat.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Steve Langasek <steve.langasek@canonical.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Konrad Rzeszutek Wilk <konrad@kernel.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: <stable@vger.kernel.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

This patch adds default module loading and uses it to load the default
block elevator.  During boot, it's called right after initramfs or
initrd is made available and right before control is passed to
userland.  This ensures that as long as the modules are available in
the usual places in initramfs, initrd or the root filesystem, the
default modules are loaded as soon as possible.

This will replace the on-demand elevator module loading from elevator
init path.

v2: Fixed build breakage when !CONFIG_BLOCK.  Reported by kbuild test
    robot.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alex Riesen <raa.lkml@gmail.com>
Cc: Fengguang We <fengguang.wu@intel.com>

Commit d6b21238 "make sure that we always have a return path from
kernel_execve()" reshuffled kernel_init()/init_post() to ensure that
kernel_execve() has a caller to return to.

It removed __init annotation for kernel_init() and introduced/calls a
new routine kernel_init_freeable(). Latter however is inlined by any
reasonable compiler (ARC gcc 4.4 in this case), causing slight code
bloat.

This patch forces kernel_init_freeable() as noinline reducing the .text

bloat-o-meter vmlinux vmlinux_new
add/remove: 1/0 grow/shrink: 0/1 up/down: 374/-334 (40)
function                        old     new   delta
kernel_init_freeable              -     374    +374 (.init.text)
kernel_init                     628     294    -334 (.text)
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

All architectures have
	CONFIG_GENERIC_KERNEL_THREAD
	CONFIG_GENERIC_KERNEL_EXECVE
	__ARCH_WANT_SYS_EXECVE
None of them have __ARCH_WANT_KERNEL_EXECVE and there are only two callers
of kernel_execve() (which is a trivial wrapper for do_execve() now) left.
Kill the conditionals and make both callers use do_execve().
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This reverts commit bd52276f ("x86-64/efi: Use EFI to deal with
platform wall clock (again)"), and the two supporting commits:

  da5a108d: "x86/kernel: remove tboot 1:1 page table creation code"

  185034e7: "x86, efi: 1:1 pagetable mapping for virtual EFI calls")

as they all depend semantically on commit 53b87cf0 ("x86, mm:
Include the entire kernel memory map in trampoline_pgd") that got
reverted earlier due to the problems it caused.

This was pointed out by Yinghai Lu, and verified by me on my Macbook Air
that uses EFI.
Pointed-out-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

N_HIGH_MEMORY stands for the nodes that has normal or high memory.
N_MEMORY stands for the nodes that has any memory.

The code here need to handle with the nodes which have memory, we should
use N_MEMORY instead.
Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: NWen Congyang <wency@cn.fujitsu.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Lin Feng <linfeng@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Instead of setting child_reaper and SIGNAL_UNKILLABLE one way
for the system init process, and another way for pid namespace
init processes test pid->nr == 1 and use the same code for both.

For the global init this results in SIGNAL_UNKILLABLE being set
much earlier in the initialization process.

This is a small cleanup and it paves the way for allowing unshare and
enter of the pid namespace as that path like our global init also will
not set CLONE_NEWPID.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>

gcc-4.1.2 inlines weak functions, which causes FRV to fail when the dummy
thread_info_cache_init() gets inlined into start_kernel().
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Other than ix86, x86-64 on EFI so far didn't set the
{g,s}et_wallclock accessors to the EFI routines, thus
incorrectly using raw RTC accesses instead.

Simply removing the #ifdef around the respective code isn't
enough, however: While so far early get-time calls were done in
physical mode, this doesn't work properly for x86-64, as virtual
addresses would still need to be set up for all runtime regions
(which wasn't the case on the system I have access to), so
instead the patch moves the call to efi_enter_virtual_mode()
ahead (which in turn allows to drop all code related to calling
efi-get-time in physical mode).

Additionally the earlier calling of efi_set_executable()
requires the CPA code to cope, i.e. during early boot it must be
avoided to call cpa_flush_array(), as the first thing this
function does is a BUG_ON(irqs_disabled()).

Also make the two EFI functions in question here static -
they're not being referenced elsewhere.

History:

    This commit was originally merged as bacef661 ("x86-64/efi:
    Use EFI to deal with platform wall clock") but it resulted in some
    ASUS machines no longer booting due to a firmware bug, and so was
    reverted in f026cfa8. A pre-emptive fix for the buggy ASUS
    firmware was merged in 03a1c254975e ("x86, efi: 1:1 pagetable
    mapping for virtual EFI calls") so now this patch can be
    reapplied.
Signed-off-by: NJan Beulich <jbeulich@suse.com>
Tested-by: NMatt Fleming <matt.fleming@intel.com>
Acked-by: NMatthew Garrett <mjg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com> [added commit history]

* allow kernel_execve() leave the actual return to userland to
caller (selected by CONFIG_GENERIC_KERNEL_EXECVE).  Callers
updated accordingly.
* architecture that does select GENERIC_KERNEL_EXECVE in its
Kconfig should have its ret_from_kernel_thread() do this:
	call schedule_tail
	call the callback left for it by copy_thread(); if it ever
returns, that's because it has just done successful kernel_execve()
	jump to return from syscall
IOW, its only difference from ret_from_fork() is that it does call the
callback.
* such an architecture should also get rid of ret_from_kernel_execve()
and __ARCH_WANT_KERNEL_EXECVE

This is the last part of infrastructure patches in that area - from
that point on work on different architectures can live independently.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The only place where kernel_execve() is called without a way to
return to the caller of kernel_thread() callback is kernel_post().
Reorganize kernel_init()/kernel_post() - instead of the former
calling the latter in the end (and getting freed by it), have the
latter *begin* with calling the former (and turn the latter into
kernel_thread() callback, of course).
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

After both prio_tree users have been converted to use red-black trees,
there is no need to keep around the prio tree library anymore.
Signed-off-by: NMichel Lespinasse <walken@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The ACPI BGRT driver accesses the BIOS logo image when it initializes.
However, ACPI 5.0 (which introduces the BGRT) recommends putting the
logo image in EFI boot services memory, so that the OS can reclaim that
memory.  Production systems follow this recommendation, breaking the
ACPI BGRT driver.

Move the bulk of the BGRT code to run during a new EFI late
initialization phase, which occurs after switching EFI to virtual mode,
and after initializing ACPI, but before freeing boot services memory.
Copy the BIOS logo image to kernel memory at that point, and make it
accessible to the BGRT driver.  Rework the existing ACPI BGRT driver to
act as a simple wrapper exposing that image (and the properties from the
BGRT) via sysfs.
Signed-off-by: NJosh Triplett <josh@joshtriplett.org>
Link: http://lkml.kernel.org/r/93ce9f823f1c1f3bb88bdd662cce08eee7a17f5d.1348876882.git.josh@joshtriplett.orgSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Some new ACPI 5.0 tables reference resources stored in boot services
memory, so keep that memory around until we have ACPI and can extract
data from it.
Signed-off-by: NJosh Triplett <josh@joshtriplett.org>
Link: http://lkml.kernel.org/r/baaa6d44bdc4eb0c58e5d1b4ccd2c729f854ac55.1348876882.git.josh@joshtriplett.orgSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

This reverts commit bacef661.

This commit has been found to cause serious regressions on a number of
ASUS machines at the least.  We probably need to provide a 1:1 map in
addition to the EFI virtual memory map in order for this to work.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Reported-and-bisected-by: NJérôme Carretero <cJ-ko@zougloub.eu>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120805172903.5f8bb24c@zougloub.eu

When hotadd_new_pgdat() is called to create new pgdat for a new node, a
fallback zonelist should be created for the new node.  There's code to try
to achieve that in hotadd_new_pgdat() as below:

	/*
	 * The node we allocated has no zone fallback lists. For avoiding
	 * to access not-initialized zonelist, build here.
	 */
	mutex_lock(&zonelists_mutex);
	build_all_zonelists(pgdat, NULL);
	mutex_unlock(&zonelists_mutex);

But it doesn't work as expected.  When hotadd_new_pgdat() is called, the
new node is still in offline state because node_set_online(nid) hasn't
been called yet.  And build_all_zonelists() only builds zonelists for
online nodes as:

        for_each_online_node(nid) {
                pg_data_t *pgdat = NODE_DATA(nid);

                build_zonelists(pgdat);
                build_zonelist_cache(pgdat);
        }

Though we hope to create zonelist for the new pgdat, but it doesn't.  So
add a new parameter "pgdat" the build_all_zonelists() to build pgdat for
the new pgdat too.
Signed-off-by: NJiang Liu <liuj97@gmail.com>
Signed-off-by: NXishi Qiu <qiuxishi@huawei.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Keping Chen <chenkeping@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

main.c has initcall_level_names[] for parse_args to print in debug messages,
add comments to keep them in sync with initcalls defined in init.h.

Also add "loadable" into comment re not using *_initcall macros in
modules, to disambiguate from kernel/params.c and other builtins.
Signed-off-by: NJim Cromie <jim.cromie@gmail.com>
Acked-by: NBorislav Petkov <borislav.petkov@amd.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

... and schedule_work() for interrupt/kernel_thread callers
(and yes, now it *is* OK to call from interrupt).

We are guaranteed that __fput() will be done before we return
to userland (or exit).  Note that for fput() from a kernel
thread we get an async behaviour; it's almost always OK, but
sometimes you might need to have __fput() completed before
you do anything else.  There are two mechanisms for that -
a general barrier (flush_delayed_fput()) and explicit
__fput_sync().  Both should be used with care (as was the
case for fput() from kernel threads all along).  See comments
in fs/file_table.c for details.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

9fb48c74 ("params: add 3rd arg to option handler callback
signature") added similar lines to dmesg:

initlevel:0=early, 4 registered initcalls
initlevel:1=core, 31 registered initcalls
initlevel:2=postcore, 11 registered initcalls
initlevel:3=arch, 7 registered initcalls
initlevel:4=subsys, 40 registered initcalls
initlevel:5=fs, 30 registered initcalls
initlevel:6=device, 250 registered initcalls
initlevel:7=late, 35 registered initcalls

but they don't contain any info for the general user staring at dmesg.
I'm very doubtful the count of initcalls registered per level helps
anyone so drop that output completely.

Cc: Jim Cromie <jim.cromie@gmail.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jason Baron <jbaron@redhat.com>
Signed-off-by: NBorislav Petkov <borislav.petkov@amd.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Commit 026cee00 "params:
<level>_initcall-like kernel parameters" set old-style module
parameters to level 0.  And we call those level 0 calls where we used
to, early in start_kernel().

We also loop through the initcall levels and call the levelled
module_params before the corresponding initcall.  Unfortunately level
0 is early_init(), so we call the standard module_param calls twice.

(Turns out most things don't care, but at least ubi.mtd does).

Change the level to -1 for standard module_param calls.
Reported-by: NBenoît Thébaudeau <benoit.thebaudeau@advansee.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org