Bye-bye Performance Counters, welcome Performance Events!

In the past few months the perfcounters subsystem has grown out its
initial role of counting hardware events, and has become (and is
becoming) a much broader generic event enumeration, reporting, logging,
monitoring, analysis facility.

Naming its core object 'perf_counter' and naming the subsystem
'perfcounters' has become more and more of a misnomer. With pending
code like hw-breakpoints support the 'counter' name is less and
less appropriate.

All in one, we've decided to rename the subsystem to 'performance
events' and to propagate this rename through all fields, variables
and API names. (in an ABI compatible fashion)

The word 'event' is also a bit shorter than 'counter' - which makes
it slightly more convenient to write/handle as well.

Thanks goes to Stephane Eranian who first observed this misnomer and
suggested a rename.

User-space tooling and ABI compatibility is not affected - this patch
should be function-invariant. (Also, defconfigs were not touched to
keep the size down.)

This patch has been generated via the following script:

  FILES=$(find * -type f | grep -vE 'oprofile|[^K]config')

  sed -i \
    -e 's/PERF_EVENT_/PERF_RECORD_/g' \
    -e 's/PERF_COUNTER/PERF_EVENT/g' \
    -e 's/perf_counter/perf_event/g' \
    -e 's/nb_counters/nb_events/g' \
    -e 's/swcounter/swevent/g' \
    -e 's/tpcounter_event/tp_event/g' \
    $FILES

  for N in $(find . -name perf_counter.[ch]); do
    M=$(echo $N | sed 's/perf_counter/perf_event/g')
    mv $N $M
  done

  FILES=$(find . -name perf_event.*)

  sed -i \
    -e 's/COUNTER_MASK/REG_MASK/g' \
    -e 's/COUNTER/EVENT/g' \
    -e 's/\<event\>/event_id/g' \
    -e 's/counter/event/g' \
    -e 's/Counter/Event/g' \
    $FILES

... to keep it as correct as possible. This script can also be
used by anyone who has pending perfcounters patches - it converts
a Linux kernel tree over to the new naming. We tried to time this
change to the point in time where the amount of pending patches
is the smallest: the end of the merge window.

Namespace clashes were fixed up in a preparatory patch - and some
stylistic fallout will be fixed up in a subsequent patch.

( NOTE: 'counters' are still the proper terminology when we deal
  with hardware registers - and these sed scripts are a bit
  over-eager in renaming them. I've undone some of that, but
  in case there's something left where 'counter' would be
  better than 'event' we can undo that on an individual basis
  instead of touching an otherwise nicely automated patch. )
Suggested-by: NStephane Eranian <eranian@google.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NPaul Mackerras <paulus@samba.org>
Reviewed-by: NArjan van de Ven <arjan@linux.intel.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <linux-arch@vger.kernel.org>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Devtmpfs lets the kernel create a tmpfs instance called devtmpfs
very early at kernel initialization, before any driver-core device
is registered. Every device with a major/minor will provide a
device node in devtmpfs.

Devtmpfs can be changed and altered by userspace at any time,
and in any way needed - just like today's udev-mounted tmpfs.
Unmodified udev versions will run just fine on top of it, and will
recognize an already existing kernel-created device node and use it.
The default node permissions are root:root 0600. Proper permissions
and user/group ownership, meaningful symlinks, all other policy still
needs to be applied by userspace.

If a node is created by devtmps, devtmpfs will remove the device node
when the device goes away. If the device node was created by
userspace, or the devtmpfs created node was replaced by userspace, it
will no longer be removed by devtmpfs.

If it is requested to auto-mount it, it makes init=/bin/sh work
without any further userspace support. /dev will be fully populated
and dynamic, and always reflect the current device state of the kernel.
With the commonly used dynamic device numbers, it solves the problem
where static devices nodes may point to the wrong devices.

It is intended to make the initial bootup logic simpler and more robust,
by de-coupling the creation of the inital environment, to reliably run
userspace processes, from a complex userspace bootstrap logic to provide
a working /dev.
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NJan Blunck <jblunck@suse.de>
Tested-By: NHarald Hoyer <harald@redhat.com>
Tested-By: NScott James Remnant <scott@ubuntu.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Ingo was getting warnings from rcu_scheduler_starting()
indicating that context switches had occurred before RCU ended
its special early-boot handling of grace periods.

This is a dangerous condition, as it indicates that RCU might
have prematurely ended grace periods.  This exploratory fix
moves rcu_scheduler_starting() earlier in boot.
Reported-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Move tboot.h from asm to linux to fix the build errors of intel_txt
patch on non-X86 platforms. Remove the tboot code from generic code
init/main.c and kernel/cpu.c.
Signed-off-by: NShane Wang <shane.wang@intel.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Some architectures initialize clocks and timers in late_time_init and
x86 wants to do the same to avoid FIXMAP hackery for calibrating the
TSC. That would result in undefined sched_clock readout and wreckaged
printk timestamps again. We probably have those already on archs which
do all their time/clock setup in late_time_init.

There is no harm to move that after late_time_init except that a few
more boot timestamps are stale. The scheduler is not active at that
point so no real wreckage is expected.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
LKML-Reference: <new-submission>
Cc: linux-arch@vger.kernel.org

Now that CONFIG_TREE_PREEMPT_RCU is in place, there is no
further need for CONFIG_PREEMPT_RCU.  Remove it, along with
whatever subtle bugs it may (or may not) contain.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: josht@linux.vnet.ibm.com
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
LKML-Reference: <125097461396-git-send-email->
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Create a kernel/rcutree_plugin.h file that contains definitions
for preemptable RCU (or, under the #else branch of the #ifdef,
empty definitions for the classic non-preemptable semantics).
These definitions fit into plugins defined in kernel/rcutree.c
for this purpose.

This variant of preemptable RCU uses a new algorithm whose
read-side expense is roughly that of classic hierarchical RCU
under CONFIG_PREEMPT. This new algorithm's update-side expense
is similar to that of classic hierarchical RCU, and, in absence
of read-side preemption or blocking, is exactly that of classic
hierarchical RCU.  Perhaps more important, this new algorithm
has a much simpler implementation, saving well over 1,000 lines
of code compared to mainline's implementation of preemptable
RCU, which will hopefully be retired in favor of this new
algorithm.

The simplifications are obtained by maintaining per-task
nesting state for running tasks, and using a simple
lock-protected algorithm to handle accounting when tasks block
within RCU read-side critical sections, making use of lessons
learned while creating numerous user-level RCU implementations
over the past 18 months.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: josht@linux.vnet.ibm.com
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
LKML-Reference: <12509746134003-git-send-email->
Signed-off-by: NIngo Molnar <mingo@elte.hu>

One of my testboxes triggered this nasty stack overflow crash
during SCSI probing:

[    5.874004] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[    5.875004] device: 'sda': device_add
[    5.878004] BUG: unable to handle kernel NULL pointer dereference at 00000a0c
[    5.878004] IP: [<b1008321>] print_context_stack+0x81/0x110
[    5.878004] *pde = 00000000
[    5.878004] Thread overran stack, or stack corrupted
[    5.878004] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
[    5.878004] last sysfs file:
[    5.878004]
[    5.878004] Pid: 1, comm: swapper Not tainted (2.6.31-rc6-tip-01272-g9919e28-dirty #5685)
[    5.878004] EIP: 0060:[<b1008321>] EFLAGS: 00010083 CPU: 0
[    5.878004] EIP is at print_context_stack+0x81/0x110
[    5.878004] EAX: cf8a3000 EBX: cf8a3fe4 ECX: 00000049 EDX: 00000000
[    5.878004] ESI: b1cfce84 EDI: 00000000 EBP: cf8a3018 ESP: cf8a2ff4
[    5.878004]  DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
[    5.878004] Process swapper (pid: 1, ti=cf8a2000 task=cf8a8000 task.ti=cf8a3000)
[    5.878004] Stack:
[    5.878004]  b1004867 fffff000 cf8a3ffc
[    5.878004] Call Trace:
[    5.878004]  [<b1004867>] ? kernel_thread_helper+0x7/0x10
[    5.878004] BUG: unable to handle kernel NULL pointer dereference at 00000a0c
[    5.878004] IP: [<b1008321>] print_context_stack+0x81/0x110
[    5.878004] *pde = 00000000
[    5.878004] Thread overran stack, or stack corrupted
[    5.878004] Oops: 0000 [#2] PREEMPT SMP DEBUG_PAGEALLOC

The oops did not reveal any more details about the real stack
that we have and the system got into an infinite loop of
recursive pagefaults.

So i booted with CONFIG_STACK_TRACER=y and the 'stacktrace' boot
parameter. The box did not crash (timings/conditions probably
changed a tiny bit to trigger the catastrophic crash), but the
/debug/tracing/stack_trace file was rather revealing:

        Depth    Size   Location    (72 entries)
        -----    ----   --------
  0)     3704      52   __change_page_attr+0xb8/0x290
  1)     3652      24   __change_page_attr_set_clr+0x43/0x90
  2)     3628      60   kernel_map_pages+0x108/0x120
  3)     3568      40   prep_new_page+0x7d/0x130
  4)     3528      84   get_page_from_freelist+0x106/0x420
  5)     3444     116   __alloc_pages_nodemask+0xd7/0x550
  6)     3328      36   allocate_slab+0xb1/0x100
  7)     3292      36   new_slab+0x1c/0x160
  8)     3256      36   __slab_alloc+0x133/0x2b0
  9)     3220       4   kmem_cache_alloc+0x1bb/0x1d0
 10)     3216     108   create_object+0x28/0x250
 11)     3108      40   kmemleak_alloc+0x81/0xc0
 12)     3068      24   kmem_cache_alloc+0x162/0x1d0
 13)     3044      52   scsi_pool_alloc_command+0x29/0x70
 14)     2992      20   scsi_host_alloc_command+0x22/0x70
 15)     2972      24   __scsi_get_command+0x1b/0x90
 16)     2948      28   scsi_get_command+0x35/0x90
 17)     2920      24   scsi_setup_blk_pc_cmnd+0xd4/0x100
 18)     2896     128   sd_prep_fn+0x332/0xa70
 19)     2768      36   blk_peek_request+0xe7/0x1d0
 20)     2732      56   scsi_request_fn+0x54/0x520
 21)     2676      12   __generic_unplug_device+0x2b/0x40
 22)     2664      24   blk_execute_rq_nowait+0x59/0x80
 23)     2640     172   blk_execute_rq+0x6b/0xb0
 24)     2468      32   scsi_execute+0xe0/0x140
 25)     2436      64   scsi_execute_req+0x152/0x160
 26)     2372      60   scsi_vpd_inquiry+0x6c/0x90
 27)     2312      44   scsi_get_vpd_page+0x112/0x160
 28)     2268      52   sd_revalidate_disk+0x1df/0x320
 29)     2216      92   rescan_partitions+0x98/0x330
 30)     2124      52   __blkdev_get+0x309/0x350
 31)     2072       8   blkdev_get+0xf/0x20
 32)     2064      44   register_disk+0xff/0x120
 33)     2020      36   add_disk+0x6e/0xb0
 34)     1984      44   sd_probe_async+0xfb/0x1d0
 35)     1940      44   __async_schedule+0xf4/0x1b0
 36)     1896       8   async_schedule+0x12/0x20
 37)     1888      60   sd_probe+0x305/0x360
 38)     1828      44   really_probe+0x63/0x170
 39)     1784      36   driver_probe_device+0x5d/0x60
 40)     1748      16   __device_attach+0x49/0x50
 41)     1732      32   bus_for_each_drv+0x5b/0x80
 42)     1700      24   device_attach+0x6b/0x70
 43)     1676      16   bus_attach_device+0x47/0x60
 44)     1660      76   device_add+0x33d/0x400
 45)     1584      52   scsi_sysfs_add_sdev+0x6a/0x2c0
 46)     1532     108   scsi_add_lun+0x44b/0x460
 47)     1424     116   scsi_probe_and_add_lun+0x182/0x4e0
 48)     1308      36   __scsi_add_device+0xd9/0xe0
 49)     1272      44   ata_scsi_scan_host+0x10b/0x190
 50)     1228      24   async_port_probe+0x96/0xd0
 51)     1204      44   __async_schedule+0xf4/0x1b0
 52)     1160       8   async_schedule+0x12/0x20
 53)     1152      48   ata_host_register+0x171/0x1d0
 54)     1104      60   ata_pci_sff_activate_host+0xf3/0x230
 55)     1044      44   ata_pci_sff_init_one+0xea/0x100
 56)     1000      48   amd_init_one+0xb2/0x190
 57)      952       8   local_pci_probe+0x13/0x20
 58)      944      32   pci_device_probe+0x68/0x90
 59)      912      44   really_probe+0x63/0x170
 60)      868      36   driver_probe_device+0x5d/0x60
 61)      832      20   __driver_attach+0x89/0xa0
 62)      812      32   bus_for_each_dev+0x5b/0x80
 63)      780      12   driver_attach+0x1e/0x20
 64)      768      72   bus_add_driver+0x14b/0x2d0
 65)      696      36   driver_register+0x6e/0x150
 66)      660      20   __pci_register_driver+0x53/0xc0
 67)      640       8   amd_init+0x14/0x16
 68)      632     572   do_one_initcall+0x2b/0x1d0
 69)       60      12   do_basic_setup+0x56/0x6a
 70)       48      20   kernel_init+0x84/0xce
 71)       28      28   kernel_thread_helper+0x7/0x10

There's a lot of fat functions on that stack trace, but
the largest of all is do_one_initcall(). This is due to
the boot trace entry variables being on the stack.

Fixing this is relatively easy, initcalls are fundamentally
serialized, so we can move the local variables to file scope.

Note that this large stack footprint was present for a
couple of months already - what pushed my system over
the edge was the addition of kmemleak to the call-chain:

  6)     3328      36   allocate_slab+0xb1/0x100
  7)     3292      36   new_slab+0x1c/0x160
  8)     3256      36   __slab_alloc+0x133/0x2b0
  9)     3220       4   kmem_cache_alloc+0x1bb/0x1d0
 10)     3216     108   create_object+0x28/0x250
 11)     3108      40   kmemleak_alloc+0x81/0xc0
 12)     3068      24   kmem_cache_alloc+0x162/0x1d0
 13)     3044      52   scsi_pool_alloc_command+0x29/0x70

This pushes the total to ~3800 bytes, only a tiny bit
more was needed to corrupt the on-kernel-stack thread_info.

The fix reduces the stack footprint from 572 bytes
to 28 bytes.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: <stable@kernel.org>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

nr_cpu_ids is dependent only on cpu_possible_map and
setup_per_cpu_areas() already depends on cpu_possible_map and will use
nr_cpu_ids.  Initialize nr_cpu_ids before setting up percpu areas.
Signed-off-by: NTejun Heo <tj@kernel.org>

If user has already enabled profiling support in the kernel
(for oprofile, old-style profiling of ftrace) then offer up
perfcounters with a y default in interactive kconfig sessions.

Still keep it off by default otherwise.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Explain what tracepoint profiling sources are about.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NJeff Garzik <jeff@garzik.org>
LKML-Reference: <1248856508.6987.3041.camel@twins>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Support for graceful handling of kernel reboots after an Intel(R) TXT launch.

Without this patch, attempting to reboot or halt the system will cause the
TXT hardware to lock memory upon system restart because the secrets-in-memory
flag that was set on launch was never cleared.  This will in turn cause BIOS
to execute a TXT Authenticated Code Module (ACM) that will scrub all of memory
and then unlock it.  Depending on the amount of memory in the system and its type,
this may take some time.

This patch creates a 1:1 address mapping to the tboot module and then calls back
into tboot so that it may properly and securely clean up system state and clear
the secrets-in-memory flag.  When it has completed these steps, the tboot module
will reboot or halt the system.

 arch/x86/kernel/reboot.c |    8 ++++++++
 init/main.c              |    3 +++
 2 files changed, 11 insertions(+)
Signed-off-by: NJoseph Cihula <joseph.cihula@intel.com>
Signed-off-by: NShane Wang <shane.wang@intel.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Fix a missed rename in EVENT_PROFILE support so that it gets
built and allows tracepoint tracing from the 'perf' tool.

Fix a typo in the (never before built & enabled) portion in
perf_counter.c as well, and update that code to the
attr.config changes as well.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Ben Gamari <bgamari.foss@gmail.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1246869094-21237-1-git-send-email-chris@chris-wilson.co.uk>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Remove Classic RCU, given that the combination of Tree RCU and
the proposed Bloatwatch RCU do everything that Classic RCU can
with fewer bugs.

Tree RCU has been default in x86 builds for almost six months,
and seems to be quite reliable, so there does not seem to be
much justification for keeping the Classic RCU code and config
complexity around anymore.
Signed-off-by: NPaul E. McKenney <paulmck@linux.ibm.com>
Cc: akpm@linux-foundation.org
Cc: niv@us.ibm.com
Cc: dvhltc@us.ibm.com
Cc: dipankar@in.ibm.com
Cc: dhowells@redhat.com
Cc: lethal@linux-sh.org
Cc: kernel@wantstofly.org
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch makes most !CONFIG_HAVE_SETUP_PER_CPU_AREA archs use
dynamic percpu allocator.  The first chunk is allocated using
embedding helper and 8k is reserved for modules.  This ensures that
the new allocator behaves almost identically to the original allocator
as long as static percpu variables are concerned, so it shouldn't
introduce much breakage.

s390 and alpha use custom SHIFT_PERCPU_PTR() to work around addressing
range limit the addressing model imposes.  Unfortunately, this breaks
if the address is specified using a variable, so for now, the two
archs aren't converted.

The following architectures are affected by this change.

* sh
* arm
* cris
* mips
* sparc(32)
* blackfin
* avr32
* parisc (broken, under investigation)
* m32r
* powerpc(32)

As this change makes the dynamic allocator the default one,
CONFIG_HAVE_DYNAMIC_PER_CPU_AREA is replaced with its invert -
CONFIG_HAVE_LEGACY_PER_CPU_AREA, which is added to yet-to-be converted
archs.  These archs implement their own setup_per_cpu_areas() and the
conversion is not trivial.

* powerpc(64)
* sparc(64)
* ia64
* alpha
* s390

Boot and batch alloc/free tests on x86_32 with debug code (x86_32
doesn't use default first chunk initialization).  Compile tested on
sparc(32), powerpc(32), arm and alpha.

Kyle McMartin reported that this change breaks parisc.  The problem is
still under investigation and he is okay with pushing this patch
forward and fixing parisc later.

[ Impact: use dynamic allocator for most archs w/o custom percpu setup ]
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Reviewed-by: NChristoph Lameter <cl@linux.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Bryan Wu <cooloney@kernel.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>

SLAB uses get/put_online_cpus() which use a mutex which is itself only
initialized when cpu_hotplug_init() is called.  Currently we hang suring
boot in SLAB due to doing that too late.

Reported by James Bottomley and Sachin Sant (and possibly others).
Debugged by Benjamin Herrenschmidt.

This just removes the dynamic initialization of the data structures, and
replaces it with a static one, avoiding this dependency entirely, and
removing one unnecessary special initcall.
Tested-by: NSachin Sant <sachinp@in.ibm.com>
Tested-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>
Tested-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The page allocator also needs the masking of gfp flags during boot,
so this moves it out of slab/slub and uses it with the page allocator
as well.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Call constructors (gcc-generated initcall-like functions) during kernel
start and module load.  Constructors are e.g.  used for gcov data
initialization.

Disable constructor support for usermode Linux to prevent conflicts with
host glibc.
Signed-off-by: NPeter Oberparleiter <oberpar@linux.vnet.ibm.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Acked-by: NWANG Cong <xiyou.wangcong@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Li Wei <W.Li@Sun.COM>
Cc: Michael Ellerman <michaele@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Heiko Carstens <heicars2@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <mschwid2@linux.vnet.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Some architectures need to initialize SLAB caches to be able
to allocate page tables. They do that from pgtable_cache_init()
so the later should be called earlier now, best is before
vmalloc_init().
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix allocating page cache/slab object on the unallowed node when memory
spread is set by updating tasks' mems_allowed after its cpuset's mems is
changed.

In order to update tasks' mems_allowed in time, we must modify the code of
memory policy.  Because the memory policy is applied in the process's
context originally.  After applying this patch, one task directly
manipulates anothers mems_allowed, and we use alloc_lock in the
task_struct to protect mems_allowed and memory policy of the task.

But in the fast path, we didn't use lock to protect them, because adding a
lock may lead to performance regression.  But if we don't add a lock,the
task might see no nodes when changing cpuset's mems_allowed to some
non-overlapping set.  In order to avoid it, we set all new allowed nodes,
then clear newly disallowed ones.

[lee.schermerhorn@hp.com:
  The rework of mpol_new() to extract the adjusting of the node mask to
  apply cpuset and mpol flags "context" breaks set_mempolicy() and mbind()
  with MPOL_PREFERRED and a NULL nodemask--i.e., explicit local
  allocation.  Fix this by adding the check for MPOL_PREFERRED and empty
  node mask to mpol_new_mpolicy().

  Remove the now unneeded 'nodes = NULL' from mpol_new().

  Note that mpol_new_mempolicy() is always called with a non-NULL
  'nodes' parameter now that it has been removed from mpol_new().
  Therefore, we don't need to test nodes for NULL before testing it for
  'empty'.  However, just to be extra paranoid, add a VM_BUG_ON() to
  verify this assumption.]
[lee.schermerhorn@hp.com:

  I don't think the function name 'mpol_new_mempolicy' is descriptive
  enough to differentiate it from mpol_new().

  This function applies cpuset set context, usually constraining nodes
  to those allowed by the cpuset.  However, when the 'RELATIVE_NODES flag
  is set, it also translates the nodes.  So I settled on
  'mpol_set_nodemask()', because the comment block for mpol_new() mentions
  that we need to call this function to "set nodes".

  Some additional minor line length, whitespace and typo cleanup.]
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Paul Menage <menage@google.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: NLee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

All recent distros depend on the non-deprecated sysfs layout, so
change the default value of the option to reflect that.
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This false positive is due to the fact that do_mount_root() fakes a
mount option (which is normally read from userspace), and the kernel
unconditionally reads a whole page for the mount option.

Hide the false positive by using the new __getname_gfp() with the
__GFP_NOTRACK_FALSE_POSITIVE flag.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NVegard Nossum <vegard.nossum@gmail.com>

General description: kmemcheck is a patch to the linux kernel that
detects use of uninitialized memory. It does this by trapping every
read and write to memory that was allocated dynamically (e.g. using
kmalloc()). If a memory address is read that has not previously been
written to, a message is printed to the kernel log.

Thanks to Andi Kleen for the set_memory_4k() solution.

Andrew Morton suggested documenting the shadow member of struct page.
Signed-off-by: NVegard Nossum <vegardno@ifi.uio.no>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

[export kmemcheck_mark_initialized]
[build fix for setup_max_cpus]
Signed-off-by: NIngo Molnar <mingo@elte.hu>

[rebased for mainline inclusion]
Signed-off-by: NVegard Nossum <vegardno@ifi.uio.no>

Signed-off-by: NLen Brown <len.brown@intel.com>

Help out arch porters who want to support perf counters by listing some
basic requirements.
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1244827063-24046-1-git-send-email-vapier@gentoo.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

As explained by Benjamin Herrenschmidt:

  Oh and btw, your patch alone doesn't fix powerpc, because it's missing
  a whole bunch of GFP_KERNEL's in the arch code... You would have to
  grep the entire kernel for things that check slab_is_available() and
  even then you'll be missing some.

  For example, slab_is_available() didn't always exist, and so in the
  early days on powerpc, we used a mem_init_done global that is set form
  mem_init() (not perfect but works in practice). And we still have code
  using that to do the test.

Therefore, mask out __GFP_WAIT, __GFP_IO, and __GFP_FS in the slab allocators
in early boot code to avoid enabling interrupts.
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

Now, SLAB is configured in very early stage and it can be used in
init routine now.

But replacing alloc_bootmem() in FLAT/DISCONTIGMEM's page_cgroup()
initialization breaks the allocation, now.
(Works well in SPARSEMEM case...it supports MEMORY_HOTPLUG and
 size of page_cgroup is in reasonable size (< 1 << MAX_ORDER.)

This patch revive FLATMEM+memory cgroup by using alloc_bootmem.

In future,
We stop to support FLATMEM (if no users) or rewrite codes for flatmem
completely.But this will adds more messy codes and overheads.
Reported-by: NLi Zefan <lizf@cn.fujitsu.com>
Tested-by: NLi Zefan <lizf@cn.fujitsu.com>
Tested-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

Reimplement inotify_user using fsnotify.  This should be feature for feature
exactly the same as the original inotify_user.  This does not make any changes
to the in kernel inotify feature used by audit.  Those patches (and the eventual
removal of in kernel inotify) will come after the new inotify_user proves to be
working correctly.
Signed-off-by: NEric Paris <eparis@redhat.com>
Acked-by: NAl Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>

As suggested by Christoph Lameter, introduce mm_init() now that we initialize
all the kernel memory allocations together.

Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

We can call vmalloc_init() after kmem_cache_init() and use kzalloc() instead of
the bootmem allocator when initializing vmalloc data structures.
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Acked-by: NNick Piggin <npiggin@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

This patch makes kmalloc() available earlier in the boot sequence so we can get
rid of some bootmem allocations. The bulk of the changes are due to
kmem_cache_init() being called with interrupts disabled which requires some
changes to allocator boostrap code.

Note: 32-bit x86 does WP protect test in mem_init() so we must setup traps
before we call mem_init() during boot as reported by Ingo Molnar:

  We have a hard crash in the WP-protect code:

  [    0.000000] Checking if this processor honours the WP bit even in supervisor mode...BUG: Int 14: CR2 ffcff000
  [    0.000000]      EDI 00000188  ESI 00000ac7  EBP c17eaf9c  ESP c17eaf8c
  [    0.000000]      EBX 000014e0  EDX 0000000e  ECX 01856067  EAX 00000001
  [    0.000000]      err 00000003  EIP c10135b1   CS 00000060  flg 00010002
  [    0.000000] Stack: c17eafa8 c17fd410 c16747bc c17eafc4 c17fd7e5 000011fd f8616000 c18237cc
  [    0.000000]        00099800 c17bb000 c17eafec c17f1668 000001c5 c17f1322 c166e039 c1822bf0
  [    0.000000]        c166e033 c153a014 c18237cc 00020800 c17eaff8 c17f106a 00020800 01ba5003
  [    0.000000] Pid: 0, comm: swapper Not tainted 2.6.30-tip-02161-g7a74539-dirty #52203
  [    0.000000] Call Trace:
  [    0.000000]  [<c15357c2>] ? printk+0x14/0x16
  [    0.000000]  [<c10135b1>] ? do_test_wp_bit+0x19/0x23
  [    0.000000]  [<c17fd410>] ? test_wp_bit+0x26/0x64
  [    0.000000]  [<c17fd7e5>] ? mem_init+0x1ba/0x1d8
  [    0.000000]  [<c17f1668>] ? start_kernel+0x164/0x2f7
  [    0.000000]  [<c17f1322>] ? unknown_bootoption+0x0/0x19c
  [    0.000000]  [<c17f106a>] ? __init_begin+0x6a/0x6f
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by Linus Torvalds <torvalds@linux-foundation.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

This patch adds the base support for the kernel memory leak
detector. It traces the memory allocation/freeing in a way similar to
the Boehm's conservative garbage collector, the difference being that
the unreferenced objects are not freed but only shown in
/sys/kernel/debug/kmemleak. Enabling this feature introduces an
overhead to memory allocations.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: NPekka Enberg <penberg@cs.helsinki.fi>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

Perfcounters were enabled by default to help testing - but now that we
are submitting it upstream, make it default-disabled.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The STRIP_ASM_SYMS kconfig symbol mucks up the embedded menu because
STRIP_ASM_SYMS is in the middle of the embedded menu items but it does not
depend on EMBEDDED.  Move it to beyond the end of the embedded menu so
that the menu is presented correctly.

Or if STRIP_ASM_SYMS should depend on EMBEDDED, that can also be fixed.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

There is no format specifiers left in the linux_banner, and gcc-4.3
complains seeing the printk.
Signed-off-by: NAlex Riesen <raa.lkml@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With the removal of duplicate unpack_to_rootfs() (commit
df52092f) the messages displayed do not
actually correspond to what the kernel is doing.  In addition, depending
if ramdisks are supported or not, the messages are not at all the same.

So keep the messages more in sync with what is really doing the kernel,
and only display a second message in case of failure.  This also ensure
that the printk message cannot be split by other printk's.
Signed-off-by: NEric Piel <eric.piel@tremplin-utc.net>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

V3 of the early platform driver implementation.

Platform drivers are great for embedded platforms because we can separate
driver configuration from the actual driver.  So base addresses,
interrupts and other configuration can be kept with the processor or board
code, and the platform driver can be reused by many different platforms.

For early devices we have nothing today.  For instance, to configure early
timers and early serial ports we cannot use platform devices.  This
because the setup order during boot.  Timers are needed before the
platform driver core code is available.  The same goes for early printk
support.  Early in this case means before initcalls.

These early drivers today have their configuration either hard coded or
they receive it using some special configuration method.  This is working
quite well, but if we want to support both regular kernel modules and
early devices then we need to have two ways of configuring the same
driver.  A single way would be better.

The early platform driver patch is basically a set of functions that allow
drivers to register themselves and architecture code to locate them and
probe.  Registration happens through early_param().  The time for the
probe is decided by the architecture code.

See Documentation/driver-model/platform.txt for more details.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NMagnus Damm <damm@igel.co.jp>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: David Brownell <david-b@pacbell.net>
Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Change cb6ff208 ("NOMMU: Support XIP on
initramfs") seems to have broken booting from initramfs with /sbin/init
being a hardlink.

It seems like the logic required for XIP on nommu, i.e.  ftruncate to
reported cpio header file size (body_len) is broken for hardlinks, which
have a reported size of 0, and the truncate thus nukes the contents of the
file (in my case busybox), making boot impossible and ending with runaway
loop modprobe binfmt-0000 - and of course 0000 is not a valid binary
format.

My fix is to only call ftruncate if size is non-zero which fixes things
for me, but I'm not certain whether this will break XIP for those files on
nommu systems, although I would guess not.
Signed-off-by: NRandy Robertson <rmrobert@vmware.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NPaul Mundt <lethal@linux-sh.org>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

init/initramfs.c:520: warning: 'clean_rootfs' defined but not used
Signed-off-by: NNikanth Karthikesan <knikanth@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Impact: refactor code for future changes

Current kmemtrace.h is used both as header file of kmemtrace and kmem's
tracepoints definition.

Tracepoints' definition file may be used by other code, and should only have
definition of tracepoint.

We can separate include/trace/kmemtrace.h into 2 files:

  include/linux/kmemtrace.h: header file for kmemtrace
  include/trace/kmem.h:      definition of kmem tracepoints
Signed-off-by: NZhao Lei <zhaolei@cn.fujitsu.com>
Acked-by: NEduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Acked-by: NPekka Enberg <penberg@cs.helsinki.fi>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <49DEE68A.5040902@cn.fujitsu.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>