Fixed typos.
v2: Incorporated changes by Randy Dunlap.
Signed-off-by: Nicolas Kaiser <nikai@nikai.net>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
max_user_instances was removed in this commit:
commit 9df04e1f25
Author: Davide Libenzi <davidel@xmailserver.org>
Date: Thu Jan 29 14:25:26 2009 -0800
epoll: drop max_user_instances and rely only on max_user_watches
but the documentation entry was not removed.
Cc: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Lucian Adrian Grijincu <lucian.grijincu@gmail.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
v2, updated based on comments from Joe and Paul.
Update to Documentation/dontdiff, based on many updates to
various .gitignore patches over the last 2 years.
Initially begun by Michael Prokop <mika@grml.org>, with lots of
changes by Randy Dunlap.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Michael Prokop <mika@grml.org>
Cc: Joe Perches <joe@perches.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The eTSEC includes a PTP clock with quite a few features. This patch adds
support for the basic clock adjustment functions, plus two external time
stamps, one alarm, and the PPS callback.
Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
This patch adds an infrastructure for hardware clocks that implement
IEEE 1588, the Precision Time Protocol (PTP). A class driver offers a
registration method to particular hardware clock drivers. Each clock is
presented as a standard POSIX clock.
The ancillary clock features are exposed in two different ways, via
the sysfs and by a character device.
Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: John Stultz <john.stultz@linaro.org>
* 'usb-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6: (205 commits)
USB: EHCI: Remove SPARC_LEON {read,write}_be definitions from ehci.h
USB: UHCI: Support big endian GRUSBHC HC
sparc: add {read,write}*_be routines
USB: UHCI: Add support for big endian descriptors
USB: UHCI: Use ACCESS_ONCE rather than using a full compiler barrier
USB: UHCI: Add support for big endian mmio
usb-storage: Correct adjust_quirks to include latest flags
usb/isp1760: Fix possible unlink problems
usb/isp1760: Move function isp1760_endpoint_disable() within file.
USB: remove remaining usages of hcd->state from usbcore and fix regression
usb: musb: ux500: add configuration and build options for ux500 dma
usb: musb: ux500: add dma glue layer for ux500
usb: musb: ux500: add dma name for ux500
usb: musb: ux500: add ux500 specific code for gadget side
usb: musb: fix compile error
usb-storage: fix up the unusual_realtek device list
USB: gadget: f_audio: Fix invalid dereference of initdata
EHCI: don't rescan interrupt QHs needlessly
OHCI: fix regression caused by nVidia shutdown workaround
USB: OTG: msm: Free VCCCX regulator even if we can't set the voltage
...
* 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: (48 commits)
serial: 8250_pci: add support for Cronyx Omega PCI multiserial board.
tty/serial: Fix break handling for PORT_TEGRA
tty/serial: Add explicit PORT_TEGRA type
n_tracerouter and n_tracesink ldisc additions.
Intel PTI implementaiton of MIPI 1149.7.
Kernel documentation for the PTI feature.
export kernel call get_task_comm().
tty: Remove to support serial for S5P6442
pch_phub: Support new device ML7223
8250_pci: Add support for the Digi/IBM PCIe 2-port Adapter
ASoC: Update cx20442 for TTY API change
pch_uart: Support new device ML7223 IOH
parport: Use request_muxed_region for IT87 probe and lock
tty/serial: add support for Xilinx PS UART
n_gsm: Use print_hex_dump_bytes
drivers/tty/moxa.c: Put correct tty value
TTY: tty_io, annotate locking functions
TTY: serial_core, remove superfluous set_task_state
TTY: serial_core, remove invalid test
Char: moxa, fix locking in moxa_write
...
Fix up trivial conflicts in drivers/bluetooth/hci_ldisc.c and
drivers/tty/serial/Makefile.
I did the hci_ldisc thing as an evil merge, cleaning things up.
* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/staging:
hwmon: (coretemp) Fix checkpatch errors
hwmon: Remove pkgtemp driver
hwmon: (coretemp) Merge pkgtemp with coretemp
hwmon: (pmbus) Add support for Analog Devices ADM1275
hwmon: (pmbus) Support for TI UCD90xxx series Sequencer and System Health Controllers
hwmon: (pmbus) Add support for TI UCD9200 series of PWM System Controllers
hwmon: (pmbus) Use device specific function to read fan configuration
hwmon: (pmbus) Expand scope of device specific get_status function
hwmon: (pmbus) Introduce infrastructure to detect sensors and limit registers
hwmon: Driver for MAX16065 System Manager and compatibles
hwmon: (sht15) add support for CRC validation
hwmon: (sht15) add support for the status register
hwmon: (sht15) clean-up the probe function
hwmon: (sht15) general code clean-up
hwmon: Add support for MAX6642
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
b43: fix comment typo reqest -> request
Haavard Skinnemoen has left Atmel
cris: typo in mach-fs Makefile
Kconfig: fix copy/paste-ism for dell-wmi-aio driver
doc: timers-howto: fix a typo ("unsgined")
perf: Only include annotate.h once in tools/perf/util/ui/browsers/annotate.c
md, raid5: Fix spelling error in comment ('Ofcourse' --> 'Of course').
treewide: fix a few typos in comments
regulator: change debug statement be consistent with the style of the rest
Revert "arm: mach-u300/gpio: Fix mem_region resource size miscalculations"
audit: acquire creds selectively to reduce atomic op overhead
rtlwifi: don't touch with treewide double semicolon removal
treewide: cleanup continuations and remove logging message whitespace
ath9k_hw: don't touch with treewide double semicolon removal
include/linux/leds-regulator.h: fix syntax in example code
tty: fix typo in descripton of tty_termios_encode_baud_rate
xtensa: remove obsolete BKL kernel option from defconfig
m68k: fix comment typo 'occcured'
arch:Kconfig.locks Remove unused config option.
treewide: remove extra semicolons
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid: (36 commits)
HID: hid-multitouch: cosmetic changes, sort classes and devices
HID: hid-multitouch: class MT_CLS_STANTUM is redundant with MT_CLS_CONFIDENCE
HID: hid-multitouch: add support for Unitec panels
HID: hid-multitouch: add support for Touch International panels
HID: hid-multitouch: add support for GoodTouch panels
HID: hid-multitouch: add support for CVTouch panels
HID: hid-multitouch: add support for ActionStar panels
HID: hiddev: fix race between hiddev_disconnect and hiddev_release
HID: magicmouse: ignore 'ivalid report id' while switching modes
HID: fix a crash in hid_report_raw_event() function.
HID: hid-multitouch: add support for Elo TouchSystems 2515 IntelliTouch Plus
HID: assorted usage updates from hut 1.12
HID: roccat: fix actual/startup profile sysfs attribute in koneplus
HID: hid-multitouch: Add support for Lumio panels
HID: 'name' and 'phys' in 'struct hid_device' can never be NULL
HID: hid-multitouch: add support for Ilitek dual-touch panel
HID: picolcd: Avoid compile warning/error triggered by copy_from_user()
HID: add support for Logitech G27 wheel
HID: hiddev: fix error path in hiddev_read when interrupted
HID: add support for Sony Navigation Controller
...
* 'kvm-updates/2.6.40' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (131 commits)
KVM: MMU: Use ptep_user for cmpxchg_gpte()
KVM: Fix kvm mmu_notifier initialization order
KVM: Add documentation for KVM_CAP_NR_VCPUS
KVM: make guest mode entry to be rcu quiescent state
KVM: x86 emulator: Make jmp far emulation into a separate function
KVM: x86 emulator: Rename emulate_grpX() to em_grpX()
KVM: x86 emulator: Remove unused arg from emulate_pop()
KVM: x86 emulator: Remove unused arg from writeback()
KVM: x86 emulator: Remove unused arg from read_descriptor()
KVM: x86 emulator: Remove unused arg from seg_override()
KVM: Validate userspace_addr of memslot when registered
KVM: MMU: Clean up gpte reading with copy_from_user()
KVM: PPC: booke: add sregs support
KVM: PPC: booke: save/restore VRSAVE (a.k.a. USPRG0)
KVM: PPC: use ticks, not usecs, for exit timing
KVM: PPC: fix exit accounting for SPRs, tlbwe, tlbsx
KVM: PPC: e500: emulate SVR
KVM: VMX: Cache vmcs segment fields
KVM: x86 emulator: consolidate segment accessors
KVM: VMX: Avoid reading %rip unnecessarily when handling exceptions
...
Switch to debugging using dynamic printk (pr_debug()). There is no good reason
to carry custom debugging prints if there is so cool and powerful generic
dynamic printk infrastructure, see Documentation/dynamic-debug-howto.txt. With
dynamic printks we can switch on/of individual prints, per-file, per-function
and per format messages. This means that instead of doing old-fashioned
echo 1 > /sys/module/ubifs/parameters/debug_msgs
to enable general messages, we can do:
echo 'format "UBIFS DBG gen" +ptlf' > control
to enable general messages and additionally ask the dynamic printk
infrastructure to print process ID, line number and function name. So there is
no reason to keep UBIFS-specific crud if there is more powerful generic thing.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Document KVM_CAP_NR_VCPUS that can be used by the userspace to determine
maximum number of VCPUs it can create with the KVM_CREATE_VCPU ioctl.
Cc: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Avi Kivity <avi@redhat.com>
* commit '29ce831000081dd757d3116bf774aafffc4b6b20': (34 commits)
rcu: provide rcu_virt_note_context_switch() function.
rcu: get rid of signed overflow in check_cpu_stall()
rcu: optimize rcutiny
rcu: prevent call_rcu() from diving into rcu core if irqs disabled
rcu: further lower priority in rcu_yield()
rcu: introduce kfree_rcu()
rcu: fix spelling
rcu: call __rcu_read_unlock() in exit_rcu for tree RCU
rcu: Converge TINY_RCU expedited and normal boosting
rcu: remove useless ->boosted_this_gp field
rcu: code cleanups in TINY_RCU priority boosting.
rcu: Switch to this_cpu() primitives
rcu: Use WARN_ON_ONCE for DEBUG_OBJECTS_RCU_HEAD warnings
rcu: mark rcutorture boosting callback as being on-stack
rcu: add DEBUG_OBJECTS_RCU_HEAD check for alignment
rcu: Enable DEBUG_OBJECTS_RCU_HEAD from !PREEMPT
rcu: Add forward-progress diagnostic for per-CPU kthreads
rcu: add grace-period age and more kthread state to tracing
rcu: fix tracing bug thinko on boost-balk attribution
rcu: update tracing documentation for new rcutorture and rcuboost
...
Pulling in rcu_virt_note_context_switch().
Signed-off-by: Avi Kivity <avi@redhat.com>
* commit '29ce831000081dd757d3116bf774aafffc4b6b20': (34 commits)
rcu: provide rcu_virt_note_context_switch() function.
rcu: get rid of signed overflow in check_cpu_stall()
rcu: optimize rcutiny
rcu: prevent call_rcu() from diving into rcu core if irqs disabled
rcu: further lower priority in rcu_yield()
rcu: introduce kfree_rcu()
rcu: fix spelling
rcu: call __rcu_read_unlock() in exit_rcu for tree RCU
rcu: Converge TINY_RCU expedited and normal boosting
rcu: remove useless ->boosted_this_gp field
rcu: code cleanups in TINY_RCU priority boosting.
rcu: Switch to this_cpu() primitives
rcu: Use WARN_ON_ONCE for DEBUG_OBJECTS_RCU_HEAD warnings
rcu: mark rcutorture boosting callback as being on-stack
rcu: add DEBUG_OBJECTS_RCU_HEAD check for alignment
rcu: Enable DEBUG_OBJECTS_RCU_HEAD from !PREEMPT
rcu: Add forward-progress diagnostic for per-CPU kthreads
rcu: add grace-period age and more kthread state to tracing
rcu: fix tracing bug thinko on boost-balk attribution
rcu: update tracing documentation for new rcutorture and rcuboost
...
After remove the device from /sys, we have to rescan all or
find out the bridge and access /sys../device/rescan there.
this patch add /sys/.../pci_bus/.../rescan. So user can rescan more easy.
that is more clean and easy to understand.
like after remove 0000:c4:00.0, you can rescan 0000:c4 directly.
-v2: According to Jesse, use function instead of exposing attr, so could hide
#ifdef in header file.
also add code to remove rescan file in remove path.
-v3: GregKH pointed out that we should use dev_attrs to avoid racing.
So add pcibus_attrs and make it to be member of pcibus_attrs.
-v4: Change name to pcibus_dev_attrs according to GregKH
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
After the merge of pkgtemp functionality into the coretemp driver,
the pkgtemp driver is no longer necessary. Remove it.
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (45 commits)
crypto: caam - add support for sha512 variants of existing AEAD algorithms
crypto: caam - remove unused authkeylen from caam_ctx
crypto: caam - fix decryption shared vs. non-shared key setting
crypto: caam - platform_bus_type migration
crypto: aesni-intel - fix aesni build on i386
crypto: aesni-intel - Merge with fpu.ko
crypto: mv_cesa - make count_sgs() null-pointer proof
crypto: mv_cesa - copy remaining bytes to SRAM only when needed
crypto: mv_cesa - move digest state initialisation to a better place
crypto: mv_cesa - fill inner/outer IV fields only in HMAC case
crypto: mv_cesa - refactor copy_src_to_buf()
crypto: mv_cesa - no need to save digest state after the last chunk
crypto: mv_cesa - print a warning when registration of AES algos fail
crypto: mv_cesa - drop this call to mv_hash_final from mv_hash_finup
crypto: mv_cesa - the descriptor pointer register needs to be set just once
crypto: mv_cesa - use ablkcipher_request_cast instead of the manual container_of
crypto: caam - fix printk recursion for long error texts
crypto: caam - remove unused keylen from session context
hwrng: amd - enable AMD hw rnd driver for Maple PPC boards
hwrng: amd - manage resource allocation
...
A few new capabilities added to frontend.h for DVB-T2. Added these
to the documentation plus some notes explaining that they are
used by the T2 delivery system.
Signed-off-by: Steve Kerrison <steve@stevekerrison.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1446 commits)
macvlan: fix panic if lowerdev in a bond
tg3: Add braces around 5906 workaround.
tg3: Fix NETIF_F_LOOPBACK error
macvlan: remove one synchronize_rcu() call
networking: NET_CLS_ROUTE4 depends on INET
irda: Fix error propagation in ircomm_lmp_connect_response()
irda: Kill set but unused variable 'bytes' in irlan_check_command_param()
irda: Kill set but unused variable 'clen' in ircomm_connect_indication()
rxrpc: Fix set but unused variable 'usage' in rxrpc_get_transport()
be2net: Kill set but unused variable 'req' in lancer_fw_download()
irda: Kill set but unused vars 'saddr' and 'daddr' in irlan_provider_connect_indication()
atl1c: atl1c_resume() is only used when CONFIG_PM_SLEEP is defined.
rxrpc: Fix set but unused variable 'usage' in rxrpc_get_peer().
rxrpc: Kill set but unused variable 'local' in rxrpc_UDP_error_handler()
rxrpc: Kill set but unused variable 'sp' in rxrpc_process_connection()
rxrpc: Kill set but unused variable 'sp' in rxrpc_rotate_tx_window()
pkt_sched: Kill set but unused variable 'protocol' in tc_classify()
isdn: capi: Use pr_debug() instead of ifdefs.
tg3: Update version to 3.119
tg3: Apply rx_discards fix to 5719/5720
...
Fix up trivial conflicts in arch/x86/Kconfig and net/mac80211/agg-tx.c
as per Davem.
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (110 commits)
[SCSI] qla2xxx: Refactor call to qla2xxx_read_sfp for thermal temperature.
[SCSI] qla2xxx: Unify the read/write sfp mailbox command routines.
[SCSI] qla2xxx: Clear complete initialization control block.
[SCSI] qla2xxx: Allow an override of the registered maximum LUN.
[SCSI] qla2xxx: Add host number in reset and quiescent message logs.
[SCSI] qla2xxx: Correctly read sfp single byte mailbox register.
[SCSI] qla2xxx: Add qla82xx_rom_unlock() function.
[SCSI] qla2xxx: Log if qla82xx firmware fails to load from flash.
[SCSI] qla2xxx: Use passed in host to initialize local scsi_qla_host in queuecommand function
[SCSI] qla2xxx: Correct buffer start in edc sysfs debug print.
[SCSI] qla2xxx: Update firmware version after flash update for ISP82xx.
[SCSI] qla2xxx: Fix hang during driver unload when vport is active.
[SCSI] qla2xxx: Properly set the dsd_list_len for dsd_chaining in cmd type 6.
[SCSI] qla2xxx: Fix virtual port failing to login after chip reset.
[SCSI] qla2xxx: Fix vport delete hang when logins are outstanding.
[SCSI] hpsa: Change memset using sizeof(ptr) to sizeof(*ptr)
[SCSI] ipr: Rate limit DMA mapping errors
[SCSI] hpsa: add P2000 to list of shared SAS devices
[SCSI] hpsa: do not attempt PCI power management reset method if we know it won't work.
[SCSI] hpsa: remove superfluous sleeps around reset code
...
Since for-2.6.40/core was forked off the 2.6.39 devel tree, we've
had churn in the core area that makes it difficult to handle
patches for eg cfq or blk-throttle. Instead of requiring that they
be based in older versions with bugs that have been fixed later
in the rc cycle, merge in 2.6.39 final.
Also fixes up conflicts in the below files.
Conflicts:
drivers/block/paride/pcd.c
drivers/cdrom/viocd.c
drivers/ide/ide-cd.c
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
M420 is a hybrid YUV 4:2:0 packet/planar format. Two Y lines are
followed by an interleaved U/V line.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
[laurent.pinchart@ideasonboard.com: split into v4l/uvcvideo patches]
[laurent.pinchart@ideasonboard.com: add documentation]
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This patch merges the pkgtemp with coretemp driver.
The sysfs interfaces for all cores in the same pkg
are shown under one directory, in hwmon. It also
supports CONFIG_HOTPLUG_CPU. So, the sysfs interfaces
are created when each core comes online and are
removed when it goes offline.
Signed-off-by: Durgadoss R <durgadoss.r@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
[guenter.roeck@ericsson.com: Fixed section reference errors]
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Move the public API definitions to include/linux/uvcvideo.h and bump the
version number to 1.1.0. Compatibility with the old API is kept,
application can still be compiled against the private header and will
not break.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This adds detailed documentation about the driver's extension unit control
features. Part of it has been adopted from the dynctrl.txt that used to be
available in the driver's previous Subversion repository.
The documentation has been rewritten to match the current implementation, in
particular to capture the new XU control support including UVCIOC_CTRL_QUERY.
Signed-off-by: Martin Rubli <martin_rubli@logitech.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Those ioctls are deprecated, list them in the features removal schedule
for 2.6.42.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
The ability to force the encoder or decoder chip was broken by commit
0ab6e1c38d in February 2009. As nobody
complained for over 2 years, I take it that these parameters were no
longer used so we can simply drop them.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
It only contains generated files
Signed-off-by: Michael Jones <michael.jones@matrix-vision.de>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Add a 10 bits per pixel greyscale format in a bit-packed array representation,
naming it Y10B. Such pixel format is supplied for instance by the Kinect
sensor device.
Signed-off-by: Antonio Ospite <ospite@studenti.unina.it>
Signed-off-by: Jean-François Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Given how PCTV has multiple products with the same model name, include the
model number in the description and #define to make it a little more clear.
Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Manual merge of arch/powerpc/kernel/smp.c and add missing scheduler_ipi()
call to arch/powerpc/platforms/cell/interrupt.c
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (44 commits)
debugfs: Silence DEBUG_STRICT_USER_COPY_CHECKS=y warning
sysfs: remove "last sysfs file:" line from the oops messages
drivers/base/memory.c: fix warning due to "memory hotplug: Speed up add/remove when blocks are larger than PAGES_PER_SECTION"
memory hotplug: Speed up add/remove when blocks are larger than PAGES_PER_SECTION
SYSFS: Fix erroneous comments for sysfs_update_group().
driver core: remove the driver-model structures from the documentation
driver core: Add the device driver-model structures to kerneldoc
Translated Documentation/email-clients.txt
RAW driver: Remove call to kobject_put().
reboot: disable usermodehelper to prevent fs access
efivars: prevent oops on unload when efi is not enabled
Allow setting of number of raw devices as a module parameter
Introduce CONFIG_GOOGLE_FIRMWARE
driver: Google Memory Console
driver: Google EFI SMI
x86: Better comments for get_bios_ebda()
x86: get_bios_ebda_length()
misc: fix ti-st build issues
params.c: Use new strtobool function to process boolean inputs
debugfs: move to new strtobool
...
Fix up trivial conflicts in fs/debugfs/file.c due to the same patch
being applied twice, and an unrelated cleanup nearby.
* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, cpu: Fix detection of Celeron Covington stepping A1 and B0
Documentation, ABI: Update L3 cache index disable text
x86, AMD, cacheinfo: Fix L3 cache index disable checks
x86, AMD, cacheinfo: Fix fallout caused by max3 conversion
x86, cpu: Change NOP selection for certain Intel CPUs
x86, cpu: Clean up and unify the NOP selection infrastructure
x86, percpu: Use ASM_NOP4 instead of hardcoding P6_NOP4
x86, cpu: Move AMD Elan Kconfig under "Processor family"
Fix up trivial conflicts in alternative handling (commit dc326fca2b
"x86, cpu: Clean up and unify the NOP selection infrastructure" removed
some hacky 5-byte instruction stuff, while commit d430d3d7e6 "jump
label: Introduce static_branch() interface" renamed HAVE_JUMP_LABEL to
CONFIG_JUMP_LABEL in the code that went away)
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (60 commits)
sched: Fix and optimise calculation of the weight-inverse
sched: Avoid going ahead if ->cpus_allowed is not changed
sched, rt: Update rq clock when unthrottling of an otherwise idle CPU
sched: Remove unused parameters from sched_fork() and wake_up_new_task()
sched: Shorten the construction of the span cpu mask of sched domain
sched: Wrap the 'cfs_rq->nr_spread_over' field with CONFIG_SCHED_DEBUG
sched: Remove unused 'this_best_prio arg' from balance_tasks()
sched: Remove noop in alloc_rt_sched_group()
sched: Get rid of lock_depth
sched: Remove obsolete comment from scheduler_tick()
sched: Fix sched_domain iterations vs. RCU
sched: Next buddy hint on sleep and preempt path
sched: Make set_*_buddy() work on non-task entities
sched: Remove need_migrate_task()
sched: Move the second half of ttwu() to the remote cpu
sched: Restructure ttwu() some more
sched: Rename ttwu_post_activation() to ttwu_do_wakeup()
sched: Remove rq argument from ttwu_stat()
sched: Remove rq->lock from the first half of ttwu()
sched: Drop rq->lock from sched_exec()
...
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: Fix rt_rq runtime leakage bug
* 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, gart: Rename pci-gart_64.c to amd_gart_64.c
x86/amd-iommu: Use threaded interupt handler
arch/x86/kernel/pci-iommu_table.c: Convert sprintf_symbol to %pS
x86/amd-iommu: Add support for invalidate_all command
x86/amd-iommu: Add extended feature detection
x86/amd-iommu: Add ATS enable/disable code
x86/amd-iommu: Add flag to indicate IOTLB support
x86/amd-iommu: Flush device IOTLB if ATS is enabled
x86/amd-iommu: Select PCI_IOV with AMD IOMMU driver
PCI: Move ATS declarations in seperate header file
dma-debug: print information about leaked entry
x86/amd-iommu: Flush all internal TLBs when IOMMUs are enabled
x86/amd-iommu: Rename iommu_flush_device
x86/amd-iommu: Improve handling of full command buffer
x86/amd-iommu: Rename iommu_flush* to domain_flush*
x86/amd-iommu: Remove command buffer resetting logic
x86/amd-iommu: Cleanup completion-wait handling
x86/amd-iommu: Cleanup inv_pages command handling
x86/amd-iommu: Move inv-dte command building to own function
x86/amd-iommu: Move compl-wait command building to own function
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6: (34 commits)
PM: Introduce generic prepare and complete callbacks for subsystems
PM: Allow drivers to allocate memory from .prepare() callbacks safely
PM: Remove CONFIG_PM_VERBOSE
Revert "PM / Hibernate: Reduce autotuned default image size"
PM / Hibernate: Add sysfs knob to control size of memory for drivers
PM / Wakeup: Remove useless synchronize_rcu() call
kmod: always provide usermodehelper_disable()
PM / ACPI: Remove acpi_sleep=s4_nonvs
PM / Wakeup: Fix build warning related to the "wakeup" sysfs file
PM: Print a warning if firmware is requested when tasks are frozen
PM / Runtime: Rework runtime PM handling during driver removal
Freezer: Use SMP barriers
PM / Suspend: Do not ignore error codes returned by suspend_enter()
PM: Fix build issue in clock_ops.c for CONFIG_PM_RUNTIME unset
PM: Revert "driver core: platform_bus: allow runtime override of dev_pm_ops"
OMAP1 / PM: Use generic clock manipulation routines for runtime PM
PM: Remove sysdev suspend, resume and shutdown operations
PM / PowerPC: Use struct syscore_ops instead of sysdevs for PM
PM / UNICORE32: Use struct syscore_ops instead of sysdevs for PM
PM / AVR32: Use struct syscore_ops instead of sysdevs for PM
...
Commits ae38c78a03
and 00914025cc added quirk flags
US_FL_NO_READ_DISC_INFO and US_FL_NO_READ_CAPACITY_16 to
the usb-storage driver. However they did not add the corresponding flags
to adjust_quirks() in usb.c, so there was no facility for a user
to over-ride/add them via the quirks module parameter.
Signed-off-by: Karl Relton <karllinuxtest.relton@ntlworld.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This reverts commit e59fb3120b.
This reversion was due to (extreme) boot-time slowdowns on SPARC seen by
Yinghai Lu and on x86 by Ingo
.
This is a non-trivial reversion due to intervening commits.
Conflicts:
Documentation/RCU/trace.txt
kernel/rcutree.c
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add support for Analog Devices ADM1275 Hot-Swap Controller and Digital Power
Monitor
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Reviewed-by: Tom Grennan <tom.grennan@ericsson.com>
Hardware monitoring support for TI UCD90120, UCD90124, UCD9090, and UCD90910
Sequencer and System Health Controllers.
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Reviewed-by: Tom Grennan <tom.grennan@ericsson.com>
This patch adds hardware monitoring support for TI UCD9220, UCD9222, UCD9224,
UCD9240, UCD9244, UCD9246, and UCD9248 Digital PWM System Controllers.
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Reviewed-by: Tom Grennan <tom.grennan@ericsson.com>
This patch adds hardware monitoring support for Maxim MAX16065, MAX16066,
MAX16067, MAX16068, MAX16070, and MAX16071 flash-configurable system managers
with nonvolatile fault registers.
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
The sht15 sensor allows validating exchanges to and from the device
using a crc8 function. An utility function to reverse a byte has also
been added.
Signed-off-by: Jerome Oufella <jerome.oufella@savoirfairelinux.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
* Add support for:
- Heater.
- End of battery notice.
- Ability not to reload from OTP.
- Low resolution (12bit temp, 8bit humidity).
* Add an utility function to read individual bytes from the device.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
* Add a documentation file for the device.
* Respect a bit more the kernel-doc syntax.
* Rename some variables for clarity.
* Use bool type for flags.
* Use an enum for states (actions being done).
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
MAX6642 is a SMBus-Compatible Remote/Local Temperature Sensor with
Overtemperature Alarm from Maxim.
Signed-off-by: Per Dalen <per.dalen@appeartv.com>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Update the existing example in the general mpic binding to have a
separate TCRx region. Currently the example doesn't describe TCRx at
all. The one upstream device tree with an mpic timer node (p1022ds)
uses one large reg region to describe both, even though there are other
unrelated registers in between. That device tree also contains a bogus
interrupt specifier, and there's no upstream software that uses this yet,
so changing this shouldn't be a problem.
Add a full binding for the MPIC timer node, not just an example of
4-cell interrupts in the MPIC binding.
Add fsl,available-ranges, similar to msi-available-ranges.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
startup_profile and actual_profile didn't work as expected. Also
as the actual profile is persistent, the distinction between the
two was ambiguous, so both use the same code now and startup_profile
has been deprecated. Also the event is now propagated through
chardev. The userland tool has been updated to support this change.
Signed-off-by: Stefan Achatz <erazor_de@users.sourceforge.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Add documentation for the discard I/O topology parameters exported in
sysfs.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Enable/disable newly documented SMEP (Supervisor Mode Execution Protection) CPU
feature in kernel. CR4.SMEP (bit 20) is 0 at power-on. If the feature is
supported by CPU (X86_FEATURE_SMEP), enable SMEP by setting CR4.SMEP. New kernel
option nosmep disables the feature even if the feature is supported by CPU.
[ hpa: moved the call to setup_smep() until after the vendor-specific
initialization; that ensures that CPUID features are unmasked. We
will still run it before we have userspace (never mind uncontrolled
userspace). ]
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
LKML-Reference: <1305157865-31727-1-git-send-email-fenghua.yu@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
If device drivers allocate substantial amounts of memory (above 1 MB)
in their hibernate .freeze() callbacks (or in their legacy suspend
callbcks during hibernation), the subsequent creation of hibernate
image may fail due to the lack of memory. This is the case, because
the drivers' .freeze() callbacks are executed after the hibernate
memory preallocation has been carried out and the preallocated amount
of memory may be too small to cover the new driver allocations.
Unfortunately, the drivers' .prepare() callbacks also are executed
after the hibernate memory preallocation has completed, so they are
not suitable for allocating additional memory either. Thus the only
way a driver can safely allocate memory during hibernation is to use
a hibernate/suspend notifier. However, the notifiers are called
before the freezing of user space and the drivers wanting to use them
for allocating additional memory may not know how much memory needs
to be allocated at that point.
To let device drivers overcome this difficulty rework the hibernation
sequence so that the memory preallocation is carried out after the
drivers' .prepare() callbacks have been executed, so that the
.prepare() callbacks can be used for allocating additional memory
to be used by the drivers' .freeze() callbacks. Update documentation
to match the new behavior of the code.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Martin reports that on his system hibernation occasionally fails due
to the lack of memory, because the radeon driver apparently allocates
too much of it during the device freeze stage. It turns out that the
amount of memory allocated by radeon during hibernation (and
presumably during system suspend too) depends on the utilization of
the GPU (e.g. hibernating while there are two KDE 4 sessions with
compositing enabled causes radeon to allocate more memory than for
one KDE 4 session).
In principle it should be possible to use image_size to make the
memory preallocation mechanism free enough memory for the radeon
driver, but in practice it is not easy to guess the right value
because of the way the preallocation code uses image_size. For this
reason, it seems reasonable to allow users to control the amount of
memory reserved for driver allocations made after the hibernate
preallocation, which currently is constant and amounts to 1 MB.
Introduce a new sysfs file, /sys/power/reserved_size, whose value
will be used as the amount of memory to reserve for the
post-preallocation reservations made by device drivers, in bytes.
For backwards compatibility, set its default (and initial) value to
the currently used number (1 MB).
References: https://bugzilla.kernel.org/show_bug.cgi?id=34102
Reported-and-tested-by: Martin Steigerwald <Martin@Lichtvoll.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
acpi_sleep=s4_nonvs is superseded by acpi_sleep=nonvs, so remove it.
Signed-off-by: WANG Cong <amwang@redhat.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Len Brown <lenb@kernel.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
For some Dell laptops, Ubuntu had a special version of the elantech
driver with more knowledge on the devices. It can be found there:
http://zinc.ubuntu.com/git?p=mid-team/hardy-netbook.git;a=blob;f=drivers/input/mouse/elantech.c;h=d0e2cafed162428f72e3654f4dda85e08ea486b3;hb=refs/heads/abi-22
By inspecting the source code, and doing some test on a real hardware, I
have completed the protocol specification (especially for the 6 bytes
protocol). It also adds information about the mapping between the
version reported by the device and the protocol to use.
Signed-off-by: Éric Piel <eric.piel@tremplin-utc.net>
Reviewed-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Change contact person to AMD kernel mailing list, update text and
external references, drop "Users:" tag.
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Link: http://lkml.kernel.org/r/1305553188-21061-4-git-send-email-bp@amd64.org
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This provides Kernel documentation for the PTI
feature and setting line discipline drivers
on top of tty's for Linux mobile solutions.
Signed-off-by: J Freyensee <james_p_freyensee@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
UBIFS can force itself to use the 'in-the-gaps' commit method - the last resort
method which is normally invoced very very rarely. Currently this "force
int-the-gaps" debugging feature is a separate test mode. But it is a bit saner
to make it to be the "general" self-test check instead.
This patch is just a clean-up which should make the debugging code look a bit
nicer and easier to use - we have way too many debugging options.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Add support for encoders that have two detents per input signal period.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Acked-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This patch implements two new vm-ioctls to get and set the
virtual_tsc_khz if the machine supports tsc-scaling. Setting
the tsc-frequency is only possible before userspace creates
any vcpu.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Broadcom has released cards based on a new AMBA-based bus type. From a
programming point of view, this new bus type differs from AMBA and does
not use AMBA common registers. It also differs enough from SSB. We
decided that a new bus driver is needed to keep the code clean.
In its current form, the driver detects devices present on the bus and
registers them in the system. It allows registering BCMA drivers for
specified bus devices and provides them basic operations. The bus driver
itself includes two important bus managing drivers: ChipCommon core
driver and PCI(c) core driver. They are early used to allow correct
initialization.
Currently code is limited to supporting buses on PCI(e) devices, however
the driver is designed to be used also on other hosts. The host
abstraction layer is implemented and already used for PCI(e).
Support for PCI(e) hosts is working and seems to be stable (access to
80211 core was tested successfully on a few devices). We can still
optimize it by using some fixed windows, but this can be done later
without affecting any external code. Windows are just ranges in MMIO
used for accessing cores on the bus.
Cc: Greg KH <greg@kroah.com>
Cc: Michael Büsch <mb@bu3sch.de>
Cc: Larry Finger <Larry.Finger@lwfinger.net>
Cc: George Kashperko <george@znau.edu.ua>
Cc: Arend van Spriel <arend@broadcom.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Andy Botting <andy@andybotting.com>
Cc: linuxdriverproject <devel@linuxdriverproject.org>
Cc: linux-kernel@vger.kernel.org <linux-kernel@vger.kernel.org>
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This file only contains code relevant for the northbridge
gart in AMD processors. This patch renames the file to
represent this fact in the filename.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
To be coherent, all the functions/variables/constants have been renamed
to the TranslationTable style
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Remove the struct bus_type, class, device, device_driver from the
driver-model docs. With another patch add them to device.h, since
they are out of date. That will keep things up to date and provide
a better way to document this stuff.
Signed-off-by: Wanlong Gao <wanlong.gao@gmail.com>
Acked-by: Harry Wei <harryxiyou@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add the comments to the structure bus_type, device_driver, device,
class to device.h for generating the driver-model kerneldoc. With another patch
these all removed from the files in Documentation/driver-model/ since
they are out of date. That will keep things up to date and provide a better way
to document this stuff.
Signed-off-by: Wanlong Gao <wanlong.gao@gmail.com>
Acked-by: Harry Wei <harryxiyou@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The patch includes the translation Documentation/email-clients.txt.
If anyone has other problems, please let me know.
Signed-off-by: Harry Wei <harryxiyou@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
- Documentation/kvm/ to Documentation/virtual/kvm
- Documentation/uml/ to Documentation/virtual/uml
- Documentation/lguest/ to Documentation/virtual/lguest
throughout the kernel source tree.
Signed-off-by: Rob Landley <rob@landley.net>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
This is to allow number of commands reserved for use by SCSI tape drives
and medium changers to be adjusted at driver load time via the kernel
parameter cciss_tape_cmds, with a default value of 6, and a range
of 2 - 16 inclusive. Previously, the driver limited the number of
commands which could be queued to the SCSI half of the the driver
to only 2. This is to fix the problem that if you had more than
two tape drives, you couldn't, for example, erase or rewind them all
at the same time.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Increment a per-CPU counter on each pass through rcu_cpu_kthread()'s
service loop, and add it to the rcudata trace output.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
This commit adds the age in jiffies of the current grace period along
with the duration in jiffies of the longest grace period since boot
to the rcu/rcugp debugfs file. It also adds an additional "O" state
to kthread tracing to differentiate between the kthread waiting due to
having nothing to do on the one hand and waiting due to being on the
wrong CPU on the other hand.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit documents the new debugfs rcu/rcutorture and rcu/rcuboost
trace files. The description has been updated as suggested by Josh
Triplett.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit adds an indication of the state of the callback queue using
a string of four characters following the "ql=" integer queue length.
The first character is "N" if there are callbacks that have been
queued that are not yet ready to be handled by the next grace period, or
"." otherwise. The second character is "R" if there are callbacks queued
that are ready to be handled by the next grace period, or "." otherwise.
The third character is "W" if there are callbacks waiting for the current
grace period, or "." otherwise. Finally, the fourth character is "D"
if there are callbacks that have been handled by a prior grace period
and are waiting to be invoked, or ".".
Note that callbacks that are in the process of being invoked are
not shown. These callbacks would have been removed from the rcu_data
structure's list by rcu_do_batch() prior to being executed. (These
callbacks are also not reflected in the "ql=" total, FWIW.)
Also, document the new callback-queue trace information.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
The trace.txt file had obsolete output for the debugfs rcu/rcudata
file, so update it.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
If RCU priority boosting is to be meaningful, callback invocation must
be boosted in addition to preempted RCU readers. Otherwise, in presence
of CPU real-time threads, the grace period ends, but the callbacks don't
get invoked. If the callbacks don't get invoked, the associated memory
doesn't get freed, so the system is still subject to OOM.
But it is not reasonable to priority-boost RCU_SOFTIRQ, so this commit
moves the callback invocations to a kthread, which can be boosted easily.
Also add comments and properly synchronized all accesses to
rcu_cpu_kthread_task, as suggested by Lai Jiangshan.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Combine the current TREE_PREEMPT_RCU ->blocked_tasks[] lists in the
rcu_node structure into a single ->blkd_tasks list with ->gp_tasks
and ->exp_tasks tail pointers. This is in preparation for RCU priority
boosting, which will add a third dimension to the combinatorial explosion
in the ->blocked_tasks[] case, but simply a third pointer in the new
->blkd_tasks case.
Also update documentation to reflect blocked_tasks[] merge
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Commit d09b62d fixed grace-period synchronization, but left some smp_mb()
invocations in rcu_process_callbacks() that are no longer needed, but
sheer paranoia prevented them from being removed. This commit removes
them and provides a proof of correctness in their absence. It also adds
a memory barrier to rcu_report_qs_rsp() immediately before the update to
rsp->completed in order to handle the theoretical possibility that the
compiler or CPU might move massive quantities of code into a lock-based
critical section. This also proves that the sheer paranoia was not
entirely unjustified, at least from a theoretical point of view.
In addition, the old dyntick-idle synchronization depended on the fact
that grace periods were many milliseconds in duration, so that it could
be assumed that no dyntick-idle CPU could reorder a memory reference
across an entire grace period. Unfortunately for this design, the
addition of expedited grace periods breaks this assumption, which has
the unfortunate side-effect of requiring atomic operations in the
functions that track dyntick-idle state for RCU. (There is some hope
that the algorithms used in user-level RCU might be applied here, but
some work is required to handle the NMIs that user-space applications
can happily ignore. For the short term, better safe than sorry.)
This proof assumes that neither compiler nor CPU will allow a lock
acquisition and release to be reordered, as doing so can result in
deadlock. The proof is as follows:
1. A given CPU declares a quiescent state under the protection of
its leaf rcu_node's lock.
2. If there is more than one level of rcu_node hierarchy, the
last CPU to declare a quiescent state will also acquire the
->lock of the next rcu_node up in the hierarchy, but only
after releasing the lower level's lock. The acquisition of this
lock clearly cannot occur prior to the acquisition of the leaf
node's lock.
3. Step 2 repeats until we reach the root rcu_node structure.
Please note again that only one lock is held at a time through
this process. The acquisition of the root rcu_node's ->lock
must occur after the release of that of the leaf rcu_node.
4. At this point, we set the ->completed field in the rcu_state
structure in rcu_report_qs_rsp(). However, if the rcu_node
hierarchy contains only one rcu_node, then in theory the code
preceding the quiescent state could leak into the critical
section. We therefore precede the update of ->completed with a
memory barrier. All CPUs will therefore agree that any updates
preceding any report of a quiescent state will have happened
before the update of ->completed.
5. Regardless of whether a new grace period is needed, rcu_start_gp()
will propagate the new value of ->completed to all of the leaf
rcu_node structures, under the protection of each rcu_node's ->lock.
If a new grace period is needed immediately, this propagation
will occur in the same critical section that ->completed was
set in, but courtesy of the memory barrier in #4 above, is still
seen to follow any pre-quiescent-state activity.
6. When a given CPU invokes __rcu_process_gp_end(), it becomes
aware of the end of the old grace period and therefore makes
any RCU callbacks that were waiting on that grace period eligible
for invocation.
If this CPU is the same one that detected the end of the grace
period, and if there is but a single rcu_node in the hierarchy,
we will still be in the single critical section. In this case,
the memory barrier in step #4 guarantees that all callbacks will
be seen to execute after each CPU's quiescent state.
On the other hand, if this is a different CPU, it will acquire
the leaf rcu_node's ->lock, and will again be serialized after
each CPU's quiescent state for the old grace period.
On the strength of this proof, this commit therefore removes the memory
barriers from rcu_process_callbacks() and adds one to rcu_report_qs_rsp().
The effect is to reduce the number of memory barriers by one and to
reduce the frequency of execution from about once per scheduling tick
per CPU to once per grace period.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
The RCU CPU stall warnings can now be controlled using the
rcu_cpu_stall_suppress boot-time parameter or via the same parameter
from sysfs. There is therefore no longer any reason to have
kernel config parameters for this feature. This commit therefore
removes the RCU_CPU_STALL_DETECTOR and RCU_CPU_STALL_DETECTOR_RUNNABLE
kernel config parameters. The RCU_CPU_STALL_TIMEOUT parameter remains
to allow the timeout to be tuned and the RCU_CPU_STALL_VERBOSE parameter
remains to allow task-stall information to be suppressed if desired.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>