When the system has too many timers or too many aggregate
queued signals, the EAGAIN error is returned to application
from kernel, including timer_create() [POSIX.1b].

It means that the app exceeded the limit of pending signals,
but in general application writers do not expect this
outcome and the current silent failure can cause rare app
failures under very high load.

This patch adds a new message when we reach the limit
and if print_fatal_signals is enabled:

    task/1234: reached RLIMIT_SIGPENDING, dropping signal

If you see this message and your system behaved unexpectedly,
you can run following command to lift the limit:

   # ulimit -i unlimited

With help from Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>.
Signed-off-by: Naohiro Ooiwa <nooiwa@miraclelinux.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: oleg@redhat.com
LKML-Reference: <4AF6E7E2.9080406@miraclelinux.com>
[ Modified a few small details, gave surrounding code some love. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>

All architectures in the kernel increment/decrement the stack pointer
before storing values on the stack.

On architectures which have the stack grow down sas_ss_sp == sp is not
on the alternate signal stack while sas_ss_sp + sas_ss_size == sp is
on the alternate signal stack.

On architectures which have the stack grow up sas_ss_sp == sp is on
the alternate signal stack while sas_ss_sp + sas_ss_size == sp is not
on the alternate signal stack.

The current implementation fails for architectures which have the
stack grow down on the corner case where sas_ss_sp == sp.This was
reported as Debian bug #544905 on AMD64.
Simplified test case: http://download.breakpoint.cc/tc-sig-stack.c

The test case creates the following stack scenario:
   0xn0300	stack top
   0xn0200	alt stack pointer top (when switching to alt stack)
   0xn01ff	alt stack end
   0xn0100	alt stack start == stack pointer

If the signal is sent the stack pointer is pointing to the base
address of the alt stack and the kernel erroneously decides that it
has already switched to the alternate stack because of the current
check for "sp - sas_ss_sp < sas_ss_size"

On parisc (stack grows up) the scenario would be:
   0xn0200	stack pointer
   0xn01ff	alt stack end
   0xn0100	alt stack start = alt stack pointer base
   		    	  	  (when switching to alt stack)
   0xn0000	stack base

This is handled correctly by the current implementation.

[ tglx: Modified for archs which have the stack grow up (parisc) which
  	would fail with the correct implementation for stack grows
  	down. Added a check for sp >= current->sas_ss_sp which is
  	strictly not necessary but makes the code symetric for both
  	variants ]
Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: stable@kernel.org
LKML-Reference: <20091025143758.GA6653@Chamillionaire.breakpoint.cc>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  cfq-iosched: limit coop preemption
  cfq-iosched: fix bad return value cfq_should_preempt()
  backing-dev: bdi sb prune should be in the unregister path, not destroy
  Fix bio_alloc() and bio_kmalloc() documentation
  bio_put(): add bio_clone() to the list of functions in the comment

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  sata_via: Remove redundant device ID for VIA VT8261
  drivers/ata/libata: Move dereference after NULL test
  ahci: Enable SB600 64bit DMA on MSI K9A2 Platinum v2

Just remove redundant device ID for VIA VT8261.
The device ID 0x9000 and 0x9040 are redundant (for VT8261).
The 0x9040 is reserved for other usage.
Signed-off-by: Joseph Chan <josephchan@via.com.tw>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

In each case, if the NULL test on qc is needed, then the derefernce
should be after the NULL test.

A simplified version of the semantic match that detects this problem is as
follows (http://coccinelle.lip6.fr/):

// <smpl>
@match exists@
expression x, E;
identifier fld;
@@

* x->fld
  ... when != \(x = E\|&x\)
* x == NULL
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Like the Asus M2A-VM, MSI's K9A2 Platinum (MS-7376) can also support 64bit
DMA. It is a new enough board that all the BIOS releases work correctly with
64bit DMA enabled.
Signed-off-by: Mark Nelson <mdnelson8@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

CFQ has an optimization for cooperated applications. if several
io-context have close requests, they will get boost. But the
optimization get abused. Considering thread a, b, which work on one
file. a reads sectors s, s+2, s+4, ...; b reads sectors s+1, s+3, s
+5, ... Both a and b are sequential read, so they can open idle window.
a reads a sector s and goes to idle window and wakeup b. b reads sector
s+1, since in current implementation, cfq_should_preempt() thinks a and
b are cooperators, b will preempt a. b then reads sector s+1 and goes to
idle window and wakeup a. for the same reason, a will preempt b and
reads s+2. a and b will continue the circle. The circle will be very
long, and a and b will occupy whole disk queue. Other applications will
nearly have no chance to run.

Fix this limiting coop preempt until a queue is scheduled normally
again.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Commit a6151c3a inadvertently reversed
a preempt condition check, potentially causing a performance regression.
Make the meta check correct again.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Commit 592b09a4 was different from
the tested path, in that it moved the bdi super_block prune from
unregister to destroy context. This doesn't fully fix the sync hang
bug on unexpected device removal, as need to prune the bdi cache
pointer before killing flusher thread.
Tested-by: Artur Skawina <art.08.09@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

* 'for-linus' of git://github.com/at91linux/linux-2.6-at91:
  at91: at91sam9g45 family: identify several chip versions
  avr32: add two new at91 to cpu.h definition

cpu_is_xxx() macros are identifying generic at91sam9g45 chip. This patch adds
the capacity to differentiate Engineering Samples and final lots through the
inclusion of  at91_cpu_fully_identify() and the related chip IDs with chip
version field preserved.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>

Somme common drivers will need those at91 cpu_is_xxx() definitions. As
at91sam9g10 and at91sam9g45 are on the way to linus' tree, here is the patch
that adds those chips to cpu.h in AVR32 architecture.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>

* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus: (38 commits)
  MIPS: O32: Fix ppoll
  MIPS: Oprofile: Rename cpu_type from godson2 to loongson2
  MIPS: Alchemy: Fix hang with high-frequency edge interrupts
  MIPS: TXx9: Fix spi-baseclk value
  MIPS: bcm63xx: Set the correct BCM3302 CPU name
  MIPS: Loongson 2: Set cpu_has_dc_aliases and cpu_icache_snoops_remote_store
  MIPS: Avoid potential hazard on Context register
  MIPS: Octeon: Use lockless interrupt controller operations when possible.
  MIPS: Octeon: Use write_{un,}lock_irq{restore,save} to set irq affinity
  MIPS: Set S-cache linesize to 64-bytes for MTI's S-cache
  MIPS: SMTC: Avoid queing multiple reschedule IPIs
  MIPS: GCMP: Avoid accessing registers when they are not present
  MIPS: GIC: Random fixes and enhancements.
  MIPS: CMP: Fix memory barriers for correct operation of amon_cpu_start
  MIPS: Fix abs.[sd] and neg.[sd] emulation for NaN operands
  MIPS: SPRAM: Clean up support code a little
  MIPS: 1004K: Enable SPRAM support.
  MIPS: Malta: Enable PCI 2.1 compatibility in PIIX4
  MIPS: Kconfig: Fix duplicate default value for MIPS_L1_CACHE_SHIFT.
  MIPS: MTI: Fix accesses to device registers on MIPS boards
  ...

* 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
  PM: Remove some debug messages producing too much noise
  PM: Fix warning on suspend errors
  PM / Hibernate: Add newline to load_image() fail path
  PM / Hibernate: Fix error handling in save_image()
  PM / Hibernate: Fix blkdev refleaks
  PM / yenta: Split resume into early and late parts (rev. 4)

nr_processes() returns the sum of the per cpu counter process_counts for
all online CPUs. This counter is incremented for the current CPU on
fork() and decremented for the current CPU on exit(). Since a process
does not necessarily fork and exit on the same CPU the process_count for
an individual CPU can be either positive or negative and effectively has
no meaning in isolation.

Therefore calculating the sum of process_counts over only the online
CPUs omits the processes which were started or stopped on any CPU which
has since been unplugged. Only the sum of process_counts across all
possible CPUs has meaning.

The only caller of nr_processes() is proc_root_getattr() which
calculates the number of links to /proc as
        stat->nlink = proc_root.nlink + nr_processes();

You don't have to be all that unlucky for the nr_processes() to return a
negative value leading to a negative number of links (or rather, an
apparently enormous number of links). If this happens then you can get
failures where things like "ls /proc" start to fail because they got an
-EOVERFLOW from some stat() call.

Example with some debugging inserted to show what goes on:
        # ps haux|wc -l
        nr_processes: CPU0:     90
        nr_processes: CPU1:     1030
        nr_processes: CPU2:     -900
        nr_processes: CPU3:     -136
        nr_processes: TOTAL:    84
        proc_root_getattr. nlink 12 + nr_processes() 84 = 96
        84
        # echo 0 >/sys/devices/system/cpu/cpu1/online
        # ps haux|wc -l
        nr_processes: CPU0:     85
        nr_processes: CPU2:     -901
        nr_processes: CPU3:     -137
        nr_processes: TOTAL:    -953
        proc_root_getattr. nlink 12 + nr_processes() -953 = -941
        75
        # stat /proc/
        nr_processes: CPU0:     84
        nr_processes: CPU2:     -901
        nr_processes: CPU3:     -137
        nr_processes: TOTAL:    -954
        proc_root_getattr. nlink 12 + nr_processes() -954 = -942
          File: `/proc/'
          Size: 0               Blocks: 0          IO Block: 1024   directory
        Device: 3h/3d   Inode: 1           Links: 4294966354
        Access: (0555/dr-xr-xr-x)  Uid: (    0/    root)   Gid: (    0/    root)
        Access: 2009-11-03 09:06:55.000000000 +0000
        Modify: 2009-11-03 09:06:55.000000000 +0000
        Change: 2009-11-03 09:06:55.000000000 +0000

I'm not 100% convinced that the per_cpu regions remain valid for offline
CPUs, although my testing suggests that they do. If not then I think the
correct solution would be to aggregate the process_count for a given CPU
into a global base value in cpu_down().

This bug appears to pre-date the transition to git and it looks like it
may even have been present in linux-2.6.0-test7-bk3 since it looks like
the code Rusty patched in http://lwn.net/Articles/64773/ was already
wrong.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: gpio-keys - use IRQF_SHARED
  Input: winbond-cir - select LEDS_TRIGGERS
  Input: i8042 - try to get stable CTR value when initializing
  Input: atkbd - add a quirk for OQO 01+ multimedia keys

* 'fixes-s3c-2632-rc5' of git://git.fluff.org/bjdooks/linux:
  ARM: S3C2410: Fix sparse warnings in arch/arm/mach-s3c2410/gpio.c
  ARM: S3C2440: mini2440: Fix spare warnings
  ARM: S3C24XX: Fix warnings in arch/arm/plat-s3c24xx/gpio.c
  ARM: S3C2440: mini2440: Fix missing CONFIG_S3C_DEV_USB_HOST
  ARM: S3C24XX: arch/arm/plat-s3c24xx: Move dereference after NULL test
  ARM: S3C: Fix adc function exports
  ARM: S3C2410: Fix link if CONFIG_S3C2410_IOTIMING is not set
  ARM: S3C24XX: Introduce S3C2442B CPU
  ARM: S3C24XX: Define a macro to avoid compilation error
  ARM: S3C: Add info for supporting circular DMA buffers
  ARM: S3C64XX: Set rate of crystal mux
  ARM: S3C64XX: Fix S3C64XX_CLKDIV0_ARM_MASK value

* 'i2c-fixes' of git://git.fluff.org/bjdooks/linux:
  i2c-mpc: Do not generate STOP after read.
  i2c: imx: disable clock when it's possible to save power.
  i2c: imx: only imx1 needs disable delay
  i2c: imx: check busy bit when START/STOP

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2:
  nilfs2: add zero-fill for new btree node buffers
  nilfs2: fix irregular checkpoint creation due to data flush
  nilfs2: fix dirty page accounting leak causing hang at write

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (21 commits)
  mac80211: check interface is down before type change
  cfg80211: fix NULL ptr deref
  libertas if_usb: Fix crash on 64-bit machines
  mac80211: fix reason code output endianness
  mac80211: fix addba timer
  ath9k: fix misplaced semicolon on rate control
  b43: Fix DMA TX bounce buffer copying
  mac80211: fix BSS leak
  rt73usb.c : more ids
  ipw2200: fix oops on missing firmware
  gre: Fix dev_addr clobbering for gretap
  sky2: set carrier off in probe
  net: fix sk_forward_alloc corruption
  pcnet_cs: add cis of PreMax PE-200 ethernet pcmcia card
  r8169: Fix card drop incoming VLAN tagged MTU byte large jumbo frames
  ibmtr: possible Read buffer overflow?
  net: Fix RPF to work with policy routing
  net: fix kmemcheck annotations
  e1000e: rework disable K1 at 1000Mbps for 82577/82578
  e1000e: config PHY via software after resets
  ...

pm_runtime_idle() is somewhat noisy. Remove debug prints.
Signed-off-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

Fixes the point where we need to complete the power transition when
device suspend fails, so that we don't print warnings about devices
added to the device hierarchy after a failing suspend.

[rjw: Modified changelog.]
Signed-off-by: Romit Dasgupta <romit@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

Finish a line by \n when load_image fails in the middle of loading.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

There are too many retval variables in save_image(). Thus error return
value from snapshot_read_next() may be ignored and only part of the
snapshot (successfully) written.

Remove 'error' variable, invert the condition in the do-while loop
and convert the loop to use only 'ret' variable.

Switch the rest of the function to consider only 'ret'.

Also make sure we end printed line by \n if an error occurs.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

While cruising through the swsusp code I found few blkdev reference
leaks of resume_bdev.

swsusp_read: remove blkdev_put altogether. Some fail paths do
             not do that.
swsusp_check: make sure we always put a reference on fail paths
software_resume: all fail paths between swsusp_check and swsusp_read
                 omit swsusp_close. Add it in those cases. And since
                 swsusp_read doesn't drop the reference anymore, do
                 it here unconditionally.

[rjw: Fixed a small coding style issue.]
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

Commit 0c570cde
(PM / yenta: Fix cardbus suspend/resume regression) caused resume to
fail on systems with two CardBus bridges.  While the exact nature
of the failure is not known at the moment, it can be worked around by
splitting the yenta resume into an early part, executed during the
early phase of resume, that will only resume the socket and power it
up if there was a card in it during suspend, and a late part,
executed during "regular" resume, that will carry out all of the
remaining yenta resume operations.

Fixes http://bugzilla.kernel.org/show_bug.cgi?id=14334, which is a
listed regression from 2.6.31.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Dominik Brodowski <linux@dominikbrodowski.net>
Reported-by: Stephen J. Gowdy <gowdy@cern.ch>
Tested-by: Jose Marino <braket@hotmail.com>

There is nothing that disallows gpio-keys to share it's IRQ line
w/ other drivers. Make it use IRQF_SHARED in request_irq().

An example of other driver with which I'd like to share IRQ line
for GPIO buttons is ledtrig-gpio.
Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/misc/winbond-cir.c depends on LEDS_TRIGGERS so
add an appropriate select to drivers/input/misc/Kconfig
Signed-off-by: David Härdeman <david@hardeman.nu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

If user presses keys while i8042 is being initialized there is a chance
that keyboard data will be mistaken for results of Read Control Register
command causing futher troubles. Work around this issue by reading CTR
several times and stop when we get matching results.
Reported-and-tested-by: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Adds missing initialization of newly allocated b-tree node buffers.
This avoids garbage data to be mixed in b-tree node blocks.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

When nilfs flushes out dirty data to reduce memory pressure, creation
of checkpoints is wrongly postponed.  This bug causes irregular
checkpoint creation especially in small footprint systems.

To correct this issue, a timer for the checkpoint creation has to be
continued if a log writer does not create a checkpoint.

This will do the correction.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

Bruno Prémont and Dunphy, Bill noticed me that NILFS will certainly
hang on ARM-based targets.

I found this was caused by an underflow of dirty pages counter.  A
b-tree cache routine was marking page dirty without adjusting page
account information.

This fixes the dirty page accounting leak and resolves the hang on
arm-based targets.
Reported-by: Bruno Prémont <bonbons@linux-vserver.org>
Reported-by: Dunphy, Bill <WDunphy@tandbergdata.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Tested-by: Bruno Prémont <bonbons@linux-vserver.org>
Cc: stable <stable@kernel.org>

The driver always ends a read with a STOP condition which
breaks subsequent I2C reads/writes in the same transaction as
these expect to do a repeated START(ReSTART).

This will also help I2C multimaster as the bus will not be released
after the first read, but when the whole transaction ends.
Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

Enable clock before START, disable it after STOP.
Signed-off-by: Richard Zhao <linuxzsc@gmail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

check cpu_is_mx1() when disable delay.
Signed-off-by: Richard Zhao <linuxzsc@gmail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

The controller can't do anything else before it actually generates START/STOP.
So we check busy bit to make sure START/STOP is successfully finished.

If we don't check busy bit, START/STOP may fail on some fast CPUs.
Signed-off-by: Richard Zhao <linuxzsc@gmail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>