08 Apr, 2014
1 commit
-
Pull CPU hotplug notifiers registration fixes from Rafael Wysocki:
"The purpose of this single series of commits from Srivatsa S Bhat
(with a small piece from Gautham R Shenoy) touching multiple
subsystems that use CPU hotplug notifiers is to provide a way to
register them that will not lead to deadlocks with CPU online/offline
operations as described in the changelog of commit 93ae4f978ca7f ("CPU
hotplug: Provide lockless versions of callback registration
functions").The first three commits in the series introduce the API and document
it and the rest simply goes through the users of CPU hotplug notifiers
and converts them to using the new method"* tag 'cpu-hotplug-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (52 commits)
net/iucv/iucv.c: Fix CPU hotplug callback registration
net/core/flow.c: Fix CPU hotplug callback registration
mm, zswap: Fix CPU hotplug callback registration
mm, vmstat: Fix CPU hotplug callback registration
profile: Fix CPU hotplug callback registration
trace, ring-buffer: Fix CPU hotplug callback registration
xen, balloon: Fix CPU hotplug callback registration
hwmon, via-cputemp: Fix CPU hotplug callback registration
hwmon, coretemp: Fix CPU hotplug callback registration
thermal, x86-pkg-temp: Fix CPU hotplug callback registration
octeon, watchdog: Fix CPU hotplug callback registration
oprofile, nmi-timer: Fix CPU hotplug callback registration
intel-idle: Fix CPU hotplug callback registration
clocksource, dummy-timer: Fix CPU hotplug callback registration
drivers/base/topology.c: Fix CPU hotplug callback registration
acpi-cpufreq: Fix CPU hotplug callback registration
zsmalloc: Fix CPU hotplug callback registration
scsi, fcoe: Fix CPU hotplug callback registration
scsi, bnx2fc: Fix CPU hotplug callback registration
scsi, bnx2i: Fix CPU hotplug callback registration
...
20 Mar, 2014
1 commit
-
The following method of CPU hotplug callback registration is not safe
due to the possibility of an ABBA deadlock involving the cpu_add_remove_lock
and the cpu_hotplug.lock.get_online_cpus();
for_each_online_cpu(cpu)
init_cpu(cpu);register_cpu_notifier(&foobar_cpu_notifier);
put_online_cpus();
The deadlock is shown below:
CPU 0 CPU 1
----- -----Acquire cpu_hotplug.lock
[via get_online_cpus()]CPU online/offline operation
takes cpu_add_remove_lock
[via cpu_maps_update_begin()]Try to acquire
cpu_add_remove_lock
[via register_cpu_notifier()]CPU online/offline operation
tries to acquire cpu_hotplug.lock
[via cpu_hotplug_begin()]*** DEADLOCK! ***
The problem here is that callback registration takes the locks in one order
whereas the CPU hotplug operations take the same locks in the opposite order.
To avoid this issue and to provide a race-free method to register CPU hotplug
callbacks (along with initialization of already online CPUs), introduce new
variants of the callback registration APIs that simply register the callbacks
without holding the cpu_add_remove_lock during the registration. That way,
we can avoid the ABBA scenario. However, we will need to hold the
cpu_add_remove_lock throughout the entire critical section, to protect updates
to the callback/notifier chain.This can be achieved by writing the callback registration code as follows:
cpu_maps_update_begin(); [ or cpu_notifier_register_begin(); see below ]
for_each_online_cpu(cpu)
init_cpu(cpu);/* This doesn't take the cpu_add_remove_lock */
__register_cpu_notifier(&foobar_cpu_notifier);cpu_maps_update_done(); [ or cpu_notifier_register_done(); see below ]
Note that we can't use get_online_cpus() here instead of cpu_maps_update_begin()
because the cpu_hotplug.lock is dropped during the invocation of CPU_POST_DEAD
notifiers, and hence get_online_cpus() cannot provide the necessary
synchronization to protect the callback/notifier chains against concurrent
reads and writes. On the other hand, since the cpu_add_remove_lock protects
the entire hotplug operation (including CPU_POST_DEAD), we can use
cpu_maps_update_begin/done() to guarantee proper synchronization.Also, since cpu_maps_update_begin/done() is like a super-set of
get/put_online_cpus(), the former naturally protects the critical sections
from concurrent hotplug operations.Since the names cpu_maps_update_begin/done() don't make much sense in CPU
hotplug callback registration scenarios, we'll introduce new APIs named
cpu_notifier_register_begin/done() and map them to cpu_maps_update_begin/done().In summary, introduce the lockless variants of un/register_cpu_notifier() and
also export the cpu_notifier_register_begin/done() APIs for use by modules.
This way, we provide a race-free way to register hotplug callbacks as well as
perform initialization for the CPUs that are already online.Cc: Thomas Gleixner
Cc: Andrew Morton
Cc: Peter Zijlstra
Cc: Ingo Molnar
Acked-by: Oleg Nesterov
Acked-by: Toshi Kani
Reviewed-by: Gautham R. Shenoy
Signed-off-by: Srivatsa S. Bhat
Signed-off-by: Rafael J. Wysocki
19 Feb, 2014
1 commit
-
The x86 CPU feature modalias handling existed before it was reimplemented
generically. This patch aligns the x86 handling so that it
(a) reuses some more code that is now generic;
(b) uses the generic format for the modalias module metadata entry, i.e., it
now uses 'cpu:type:x86,venVVVVfamFFFFmodMMMM:feature:,XXXX,YYYY' instead of
the 'x86cpu:vendor:VVVV:family:FFFF:model:MMMM:feature:,XXXX,YYYY' that was
used before.Signed-off-by: Ard Biesheuvel
Acked-by: H. Peter Anvin
Signed-off-by: Greg Kroah-Hartman
14 Nov, 2013
1 commit
-
Pull ACPI and power management updates from Rafael J Wysocki:
- New power capping framework and the the Intel Running Average Power
Limit (RAPL) driver using it from Srinivas Pandruvada and Jacob Pan.- Addition of the in-kernel switching feature to the arm_big_little
cpufreq driver from Viresh Kumar and Nicolas Pitre.- cpufreq support for iMac G5 from Aaro Koskinen.
- Baytrail processors support for intel_pstate from Dirk Brandewie.
- cpufreq support for Midway/ECX-2000 from Mark Langsdorf.
- ARM vexpress/TC2 cpufreq support from Sudeep KarkadaNagesha.
- ACPI power management support for the I2C and SPI bus types from Mika
Westerberg and Lv Zheng.- cpufreq core fixes and cleanups from Viresh Kumar, Srivatsa S Bhat,
Stratos Karafotis, Xiaoguang Chen, Lan Tianyu.- cpufreq drivers updates (mostly fixes and cleanups) from Viresh
Kumar, Aaro Koskinen, Jungseok Lee, Sudeep KarkadaNagesha, Lukasz
Majewski, Manish Badarkhe, Hans-Christian Egtvedt, Evgeny Kapaev.- intel_pstate updates from Dirk Brandewie and Adrian Huang.
- ACPICA update to version 20130927 includig fixes and cleanups and
some reduction of divergences between the ACPICA code in the kernel
and ACPICA upstream in order to improve the automatic ACPICA patch
generation process. From Bob Moore, Lv Zheng, Tomasz Nowicki, Naresh
Bhat, Bjorn Helgaas, David E Box.- ACPI IPMI driver fixes and cleanups from Lv Zheng.
- ACPI hotplug fixes and cleanups from Bjorn Helgaas, Toshi Kani, Zhang
Yanfei, Rafael J Wysocki.- Conversion of the ACPI AC driver to the platform bus type and
multiple driver fixes and cleanups related to ACPI from Zhang Rui.- ACPI processor driver fixes and cleanups from Hanjun Guo, Jiang Liu,
Bartlomiej Zolnierkiewicz, Mathieu Rhéaume, Rafael J Wysocki.- Fixes and cleanups and new blacklist entries related to the ACPI
video support from Aaron Lu, Felipe Contreras, Lennart Poettering,
Kirill Tkhai.- cpuidle core cleanups from Viresh Kumar and Lorenzo Pieralisi.
- cpuidle drivers fixes and cleanups from Daniel Lezcano, Jingoo Han,
Bartlomiej Zolnierkiewicz, Prarit Bhargava.- devfreq updates from Sachin Kamat, Dan Carpenter, Manish Badarkhe.
- Operation Performance Points (OPP) core updates from Nishanth Menon.
- Runtime power management core fix from Rafael J Wysocki and update
from Ulf Hansson.- Hibernation fixes from Aaron Lu and Rafael J Wysocki.
- Device suspend/resume lockup detection mechanism from Benoit Goby.
- Removal of unused proc directories created for various ACPI drivers
from Lan Tianyu.- ACPI LPSS driver fix and new device IDs for the ACPI platform scan
handler from Heikki Krogerus and Jarkko Nikula.- New ACPI _OSI blacklist entry for Toshiba NB100 from Levente Kurusa.
- Assorted fixes and cleanups related to ACPI from Andy Shevchenko, Al
Stone, Bartlomiej Zolnierkiewicz, Colin Ian King, Dan Carpenter,
Felipe Contreras, Jianguo Wu, Lan Tianyu, Yinghai Lu, Mathias Krause,
Liu Chuansheng.- Assorted PM fixes and cleanups from Andy Shevchenko, Thierry Reding,
Jean-Christophe Plagniol-Villard.* tag 'pm+acpi-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (386 commits)
cpufreq: conservative: fix requested_freq reduction issue
ACPI / hotplug: Consolidate deferred execution of ACPI hotplug routines
PM / runtime: Use pm_runtime_put_sync() in __device_release_driver()
ACPI / event: remove unneeded NULL pointer check
Revert "ACPI / video: Ignore BIOS initial backlight value for HP 250 G1"
ACPI / video: Quirk initial backlight level 0
ACPI / video: Fix initial level validity test
intel_pstate: skip the driver if ACPI has power mgmt option
PM / hibernate: Avoid overflow in hibernate_preallocate_memory()
ACPI / hotplug: Do not execute "insert in progress" _OST
ACPI / hotplug: Carry out PCI root eject directly
ACPI / hotplug: Merge device hot-removal routines
ACPI / hotplug: Make acpi_bus_hot_remove_device() internal
ACPI / hotplug: Simplify device ejection routines
ACPI / hotplug: Fix handle_root_bridge_removal()
ACPI / hotplug: Refuse to hot-remove all objects with disabled hotplug
ACPI / scan: Start matching drivers after trying scan handlers
ACPI: Remove acpi_pci_slot_init() headers from internal.h
ACPI / blacklist: fix name of ThinkPad Edge E530
PowerCap: Fix build error with option -Werror=format-security
...Conflicts:
arch/arm/mach-omap2/opp.c
drivers/Kconfig
drivers/spi/spi.c
16 Oct, 2013
1 commit
-
Use for_each_node_by_type() to iterate all cpu nodes in the
system.Provide and overridable function arch_find_n_match_cpu_physical_id,
which sees if the given device node matches 'cpu' and if so sets
'*thread' when non-NULL to the cpu thread number within the core.The default implementation behaves the same as the existing code.
Add a sparc64 implementation.
Signed-off-by: David S. Miller
Tested-by: Sudeep KarkadaNagesha
Signed-off-by: Grant Likely
01 Oct, 2013
1 commit
-
cpu_hotplug_driver_lock() serializes CPU online/offline operations
when ARCH_CPU_PROBE_RELEASE is set. This lock interface is no longer
necessary with the following reason:- lock_device_hotplug() now protects CPU online/offline operations,
including the probe & release interfaces enabled by
ARCH_CPU_PROBE_RELEASE. The use of cpu_hotplug_driver_lock() is
redundant.
- cpu_hotplug_driver_lock() is only valid when ARCH_CPU_PROBE_RELEASE
is defined, which is misleading and is only enabled on powerpc.This patch removes the cpu_hotplug_driver_lock() interface. As
a result, ARCH_CPU_PROBE_RELEASE only enables / disables the cpu
probe & release interface as intended. There is no functional change
in this patch.Signed-off-by: Toshi Kani
Reviewed-by: Nathan Fontenot
Signed-off-by: Rafael J. Wysocki
27 Aug, 2013
1 commit
-
* pm-cpufreq: (60 commits)
cpufreq: pmac32-cpufreq: remove device tree parsing for cpu nodes
cpufreq: pmac64-cpufreq: remove device tree parsing for cpu nodes
cpufreq: maple-cpufreq: remove device tree parsing for cpu nodes
cpufreq: arm_big_little: remove device tree parsing for cpu nodes
cpufreq: kirkwood-cpufreq: remove device tree parsing for cpu nodes
cpufreq: spear-cpufreq: remove device tree parsing for cpu nodes
cpufreq: highbank-cpufreq: remove device tree parsing for cpu nodes
cpufreq: cpufreq-cpu0: remove device tree parsing for cpu nodes
cpufreq: imx6q-cpufreq: remove device tree parsing for cpu nodes
drivers/bus: arm-cci: avoid parsing DT for cpu device nodes
ARM: mvebu: remove device tree parsing for cpu nodes
ARM: topology: remove hwid/MPIDR dependency from cpu_capacity
of/device: add helper to get cpu device node from logical cpu index
driver/core: cpu: initialize of_node in cpu's device struture
ARM: DT/kernel: define ARM specific arch_match_cpu_phys_id
of: move of_get_cpu_node implementation to DT core library
powerpc: refactor of_get_cpu_node to support other architectures
openrisc: remove undefined of_get_cpu_node declaration
microblaze: remove undefined of_get_cpu_node declaration
cpufreq: fix bad unlock balance on !CONFIG_SMP
...
21 Aug, 2013
1 commit
-
This patch moves the generalized implementation of of_get_cpu_node from
PowerPC to DT core library, thereby adding support for retrieving cpu
node for a given logical cpu index on any architecture.The CPU subsystem can now use this function to assign of_node in the
cpu device while registering CPUs.It is recommended to use these helper function only in pre-SMP/early
initialisation stages to retrieve CPU device node pointers in logical
ordering. Once the cpu devices are registered, it can be retrieved easily
from cpu device of_node which avoids unnecessary parsing and matching.Cc: Benjamin Herrenschmidt
Cc: Grant Likely
Acked-by: Rob Herring
Signed-off-by: Sudeep KarkadaNagesha
13 Aug, 2013
1 commit
-
CPU system maps are protected with reader/writer locks. The reader
lock, get_online_cpus(), assures that the maps are not updated while
holding the lock. The writer lock, cpu_hotplug_begin(), is used to
udpate the cpu maps along with cpu_maps_update_begin().However, the ACPI processor handler updates the cpu maps without
holding the the writer lock.acpi_map_lsapic() is called from acpi_processor_hotadd_init() to
update cpu_possible_mask and cpu_present_mask. acpi_unmap_lsapic()
is called from acpi_processor_remove() to update cpu_possible_mask.
Currently, they are either unprotected or protected with the reader
lock, which is not correct.For example, the get_online_cpus() below is supposed to assure that
cpu_possible_mask is not changed while the code is iterating with
for_each_possible_cpu().get_online_cpus();
for_each_possible_cpu(cpu) {
:
}
put_online_cpus();However, this lock has no protection with CPU hotplug since the ACPI
processor handler does not use the writer lock when it updates
cpu_possible_mask. The reader lock does not serialize within the
readers.This patch protects them with the writer lock with cpu_hotplug_begin()
along with cpu_maps_update_begin(), which must be held before calling
cpu_hotplug_begin(). It also protects arch_register_cpu() /
arch_unregister_cpu(), which creates / deletes a sysfs cpu device
interface. For this purpose it changes cpu_hotplug_begin() and
cpu_hotplug_done() to global and exports them in cpu.h.Signed-off-by: Toshi Kani
Signed-off-by: Rafael J. Wysocki
15 Jul, 2013
1 commit
-
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications. For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out. Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.This removes all the uses of the __cpuinit macros from C files in
the core kernel directories (kernel, init, lib, mm, and include)
that don't really have a specific maintainer.[1] https://lkml.org/lkml/2013/5/20/589
Signed-off-by: Paul Gortmaker
05 Jul, 2013
1 commit
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Pull trivial tree updates from Jiri Kosina:
"The usual stuff from trivial tree"* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (34 commits)
treewide: relase -> release
Documentation/cgroups/memory.txt: fix stat file documentation
sysctl/net.txt: delete reference to obsolete 2.4.x kernel
spinlock_api_smp.h: fix preprocessor comments
treewide: Fix typo in printk
doc: device tree: clarify stuff in usage-model.txt.
open firmware: "/aliasas" -> "/aliases"
md: bcache: Fixed a typo with the word 'arithmetic'
irq/generic-chip: fix a few kernel-doc entries
frv: Convert use of typedef ctl_table to struct ctl_table
sgi: xpc: Convert use of typedef ctl_table to struct ctl_table
doc: clk: Fix incorrect wording
Documentation/arm/IXP4xx fix a typo
Documentation/networking/ieee802154 fix a typo
Documentation/DocBook/media/v4l fix a typo
Documentation/video4linux/si476x.txt fix a typo
Documentation/virtual/kvm/api.txt fix a typo
Documentation/early-userspace/README fix a typo
Documentation/video4linux/soc-camera.txt fix a typo
lguest: fix CONFIG_PAE -> CONFIG_x86_PAE in comment
...
13 Jun, 2013
1 commit
-
There are instances in the kernel where we would like to disable CPU
hotplug (from sysfs) during some important operation. Today the freezer
code depends on this and the code to do it was kinda tailor-made for
that.Restructure the code and make it generic enough to be useful for other
usecases too.Signed-off-by: Srivatsa S. Bhat
Signed-off-by: Robin Holt
Cc: H. Peter Anvin
Cc: Thomas Gleixner
Cc: Ingo Molnar
Cc: Russ Anderson
Cc: Robin Holt
Cc: Russell King
Cc: Guan Xuetao
Cc: Shawn Guo
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
28 May, 2013
1 commit
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Two minor changes to comments:
* Remove reference to drivers/base/sys.c, removed in 0a962657.
* CPUs are now exported by sysfs via devices/system/cpu.Signed-off-by: Robert P. J. Day
Signed-off-by: Jiri Kosina
08 Apr, 2013
2 commits
-
All idle functions in arch/* are more or less the same, plus minus a
few bugs and extra instrumentation, tickless support and other
optional items.Implement a generic idle function which resembles the functionality
found in arch/. Provide weak arch_cpu_idle_* functions which can be
overridden by the architecture code if needed.Signed-off-by: Thomas Gleixner
Cc: Linus Torvalds
Cc: Rusty Russell
Cc: Paul McKenney
Cc: Peter Zijlstra
Reviewed-by: Cc: Srivatsa S. Bhat
Cc: Magnus Damm
Link: http://lkml.kernel.org/r/20130321215233.646635455@linutronix.de
Signed-off-by: Thomas Gleixner -
For now this calls cpu_idle(), but in the long run we want to move the
cpu bringup code to the core and therefor we add a state argument.Signed-off-by: Thomas Gleixner
Cc: Linus Torvalds
Cc: Rusty Russell
Cc: Paul McKenney
Cc: Peter Zijlstra
Reviewed-by: Cc: Srivatsa S. Bhat
Cc: Magnus Damm
Link: http://lkml.kernel.org/r/20130321215233.583190032@linutronix.de
Signed-off-by: Thomas Gleixner
18 Jul, 2012
1 commit
-
Currently, all workqueue cpu hotplug operations run off
CPU_PRI_WORKQUEUE which is higher than normal notifiers. This is to
ensure that workqueue is up and running while bringing up a CPU before
other notifiers try to use workqueue on the CPU.Per-cpu workqueues are supposed to remain working and bound to the CPU
for normal CPU_DOWN_PREPARE notifiers. This holds mostly true even
with workqueue offlining running with higher priority because
workqueue CPU_DOWN_PREPARE only creates a bound trustee thread which
runs the per-cpu workqueue without concurrency management without
explicitly detaching the existing workers.However, if the trustee needs to create new workers, it creates
unbound workers which may wander off to other CPUs while
CPU_DOWN_PREPARE notifiers are in progress. Furthermore, if the CPU
down is cancelled, the per-CPU workqueue may end up with workers which
aren't bound to the CPU.While reliably reproducible with a convoluted artificial test-case
involving scheduling and flushing CPU burning work items from CPU down
notifiers, this isn't very likely to happen in the wild, and, even
when it happens, the effects are likely to be hidden by the following
successful CPU down.Fix it by using different priorities for up and down notifiers - high
priority for up operations and low priority for down operations.Workqueue cpu hotplug operations will soon go through further cleanup.
Signed-off-by: Tejun Heo
Cc: stable@vger.kernel.org
Acked-by: "Rafael J. Wysocki"
01 Jun, 2012
1 commit
-
Many architectures clear tasks' mm_cpumask like this:
read_lock(&tasklist_lock);
for_each_process(p) {
if (p->mm)
cpumask_clear_cpu(cpu, mm_cpumask(p->mm));
}
read_unlock(&tasklist_lock);Depending on the context, the code above may have several problems,
such as:1. Working with task->mm w/o getting mm or grabing the task lock is
dangerous as ->mm might disappear (exit_mm() assigns NULL under
task_lock(), so tasklist lock is not enough).2. Checking for process->mm is not enough because process' main
thread may exit or detach its mm via use_mm(), but other threads
may still have a valid mm.This patch implements a small helper function that does things
correctly, i.e.:1. We take the task's lock while whe handle its mm (we can't use
get_task_mm()/mmput() pair as mmput() might sleep);2. To catch exited main thread case, we use find_lock_task_mm(),
which walks up all threads and returns an appropriate task
(with task lock held).Also, Per Peter Zijlstra's idea, now we don't grab tasklist_lock in
the new helper, instead we take the rcu read lock. We can do this
because the function is called after the cpu is taken down and marked
offline, so no new tasks will get this cpu set in their mm mask.Signed-off-by: Anton Vorontsov
Cc: Richard Weinberger
Cc: Oleg Nesterov
Cc: Peter Zijlstra
Cc: Russell King
Cc: Benjamin Herrenschmidt
Cc: Mike Frysinger
Cc: Paul Mundt
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 May, 2012
1 commit
-
It's been broken forever (i.e. it's not scheduling in a power
aware fashion), as reported by Suresh and others sending
patches, and nobody cares enough to fix it properly ...
so remove it to make space free for something better.There's various problems with the code as it stands today, first
and foremost the user interface which is bound to topology
levels and has multiple values per level. This results in a
state explosion which the administrator or distro needs to
master and almost nobody does.Furthermore large configuration state spaces aren't good, it
means the thing doesn't just work right because it's either
under so many impossibe to meet constraints, or even if
there's an achievable state workloads have to be aware of
it precisely and can never meet it for dynamic workloads.So pushing this kind of decision to user-space was a bad idea
even with a single knob - it's exponentially worse with knobs
on every node of the topology.There is a proposal to replace the user interface with a single
3 state knob:sched_balance_policy := { performance, power, auto }
where 'auto' would be the preferred default which looks at things
like Battery/AC mode and possible cpufreq state or whatever the hw
exposes to show us power use expectations - but there's been no
progress on it in the past many months.Aside from that, the actual implementation of the various knobs
is known to be broken. There have been sporadic attempts at
fixing things but these always stop short of reaching a mergable
state.Therefore this wholesale removal with the hopes of spurring
people who care to come forward once again and work on a
coherent replacement.Signed-off-by: Peter Zijlstra
Cc: Suresh Siddha
Cc: Arjan van de Ven
Cc: Vincent Guittot
Cc: Vaidyanathan Srinivasan
Cc: Linus Torvalds
Cc: Andrew Morton
Link: http://lkml.kernel.org/r/1326104915.2442.53.camel@twins
Signed-off-by: Ingo Molnar
25 Mar, 2012
1 commit
-
Pull avoidance patches from Paul Gortmaker:
"Nearly every subsystem has some kind of header with a proto like:void foo(struct device *dev);
and yet there is no reason for most of these guys to care about the
sub fields within the device struct. This allows us to significantly
reduce the scope of headers including headers. For this instance, a
reduction of about 40% is achieved by replacing the include with the
simple fact that the device is some kind of a struct.Unlike the much larger module.h cleanup, this one is simply two
commits. One to fix the implicit users, and then one
to delete the device.h includes from the linux/include/ dir wherever
possible."* tag 'device-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux:
device.h: audit and cleanup users in main include dir
device.h: cleanup users outside of linux/include (C files)
16 Mar, 2012
1 commit
-
The header includes a lot of stuff, and
it in turn gets a lot of use just for the basic "struct device"
which appears so often.Clean up the users as follows:
1) For those headers only needing "struct device" as a pointer
in fcn args, replace the include with exactly that.2) For headers not really using anything from device.h, simply
delete the include altogether.3) For headers relying on getting device.h implicitly before
being included themselves, now explicitly include device.h4) For files in which doing #1 or #2 uncovers an implicit
dependency on some other header, fix by explicitly adding
the required header(s).Any C files that were implicitly relying on device.h to be
present have already been dealt with in advance.Total removals from #1 and #2: 51. Total additions coming
from #3: 9. Total other implicit dependencies from #4: 7.As of 3.3-rc1, there were 110, so a net removal of 42 gives
about a 38% reduction in device.h presence in include/*Signed-off-by: Paul Gortmaker
27 Jan, 2012
1 commit
-
This patch is based on Andi Kleen's work:
Implement autoprobing/loading of modules serving CPU
specific features (x86cpu autoloading).And Kay Siever's work to get rid of sysdev cpu structures
and making use of struct device instead.Before, the cpuid driver had to be loaded to get the x86cpu
autoloading feature. With this patch autoloading works through
the /sys/devices/system/cpu objectCc: Kay Sievers
Cc: Dave Jones
Cc: Jens Axboe
Cc: Herbert Xu
Cc: Huang Ying
Cc: Len Brown
Acked-by: Andi Kleen
Signed-off-by: Thomas Renninger
Acked-by: H. Peter Anvin
Signed-off-by: Greg Kroah-Hartman
08 Jan, 2012
1 commit
-
* 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (73 commits)
arm: fix up some samsung merge sysdev conversion problems
firmware: Fix an oops on reading fw_priv->fw in sysfs loading file
Drivers:hv: Fix a bug in vmbus_driver_unregister()
driver core: remove __must_check from device_create_file
debugfs: add missing #ifdef HAS_IOMEM
arm: time.h: remove device.h #include
driver-core: remove sysdev.h usage.
clockevents: remove sysdev.h
arm: convert sysdev_class to a regular subsystem
arm: leds: convert sysdev_class to a regular subsystem
kobject: remove kset_find_obj_hinted()
m86k: gpio - convert sysdev_class to a regular subsystem
mips: txx9_sram - convert sysdev_class to a regular subsystem
mips: 7segled - convert sysdev_class to a regular subsystem
sh: dma - convert sysdev_class to a regular subsystem
sh: intc - convert sysdev_class to a regular subsystem
power: suspend - convert sysdev_class to a regular subsystem
power: qe_ic - convert sysdev_class to a regular subsystem
power: cmm - convert sysdev_class to a regular subsystem
s390: time - convert sysdev_class to a regular subsystem
...Fix up conflicts with 'struct sysdev' removal from various platform
drivers that got changed:
- arch/arm/mach-exynos/cpu.c
- arch/arm/mach-exynos/irq-eint.c
- arch/arm/mach-s3c64xx/common.c
- arch/arm/mach-s3c64xx/cpu.c
- arch/arm/mach-s5p64x0/cpu.c
- arch/arm/mach-s5pv210/common.c
- arch/arm/plat-samsung/include/plat/cpu.h
- arch/powerpc/kernel/sysfs.c
and fix up cpu_is_hotpluggable() as per Greg in include/linux/cpu.h
22 Dec, 2011
1 commit
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This moves the 'cpu sysdev_class' over to a regular 'cpu' subsystem
and converts the devices to regular devices. The sysdev drivers are
implemented as subsystem interfaces now.After all sysdev classes are ported to regular driver core entities, the
sysdev implementation will be entirely removed from the kernel.Userspace relies on events and generic sysfs subsystem infrastructure
from sysdev devices, which are made available with this conversion.Cc: Haavard Skinnemoen
Cc: Hans-Christian Egtvedt
Cc: Tony Luck
Cc: Fenghua Yu
Cc: Arnd Bergmann
Cc: Benjamin Herrenschmidt
Cc: Paul Mackerras
Cc: Martin Schwidefsky
Cc: Heiko Carstens
Cc: Paul Mundt
Cc: "David S. Miller"
Cc: Chris Metcalf
Cc: Thomas Gleixner
Cc: Ingo Molnar
Cc: "H. Peter Anvin"
Cc: Borislav Petkov
Cc: Tigran Aivazian
Cc: Len Brown
Cc: Zhang Rui
Cc: Dave Jones
Cc: Peter Zijlstra
Cc: Russell King
Cc: Andrew Morton
Cc: Arjan van de Ven
Cc: "Rafael J. Wysocki"
Cc: "Srivatsa S. Bhat"
Signed-off-by: Kay Sievers
Signed-off-by: Greg Kroah-Hartman
12 Dec, 2011
1 commit
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When architectures register CPUs, they indicate whether the CPU allows
hotplugging; notably, x86 and ARM don't allow hotplugging CPU 0.
Userspace can easily query the hotpluggability of a CPU via sysfs;
however, the kernel has no convenient way of accessing that property in
an architecture-independent way. While the kernel can simply try it and
see, some code needs to distinguish between "hotplug failed" and
"hotplug has no hope of working on this CPU"; for example, rcutorture's
CPU hotplug tests want to avoid drowning out real hotplug failures with
expected failures.Expose this property via a new cpu_is_hotpluggable function, so that the
rest of the kernel can access it in an architecture-independent way.Signed-off-by: Josh Triplett
Signed-off-by: Paul E. McKenney
05 Nov, 2011
1 commit
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Remove the suspend_cpu_hotplug declaration, which doesn't correspond
to an existing variable.[rjw: Added the changelog.]
Signed-off-by: Srivatsa S. Bhat
Signed-off-by: Rafael J. Wysocki
26 Jul, 2011
1 commit
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We presently define all kinds of notifiers in notifier.h. This is not
necessary at all, since different subsystems use different notifiers, they
are almost non-related with each other.This can also save much build time. Suppose I add a new netdevice event,
really I don't have to recompile all the source, just network related.
Without this patch, all the source will be recompiled.I move the notify events near to their subsystem notifier registers, so
that they can be found more easily.This patch:
It is not necessary to share the same notifier.h.
Signed-off-by: WANG Cong
Cc: David Miller
Cc: "Rafael J. Wysocki"
Cc: Greg KH
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 Nov, 2010
1 commit
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drivers/base/intf.c was removed before the beginning of (git) time but
its Documentation stuck around. Remove it.Signed-off-by: Brandon Philips
Signed-off-by: Greg Kroah-Hartman
29 Jun, 2010
1 commit
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Reimplement CPU hotplugging support using trustee thread. On CPU
down, a trustee thread is created and each step of CPU down is
executed by the trustee and workqueue_cpu_callback() simply drives and
waits for trustee state transitions.CPU down operation no longer waits for works to be drained but trustee
sticks around till all pending works have been completed. If CPU is
brought back up while works are still draining,
workqueue_cpu_callback() tells trustee to step down and tell workers
to rebind to the cpu.As it's difficult to tell whether cwqs are empty if it's freezing or
frozen, trustee doesn't consider draining to be complete while a gcwq
is freezing or frozen (tracked by new GCWQ_FREEZING flag). Also,
workers which get unbound from their cpu are marked with WORKER_ROGUE.Trustee based implementation doesn't bring any new feature at this
point but it will be used to manage worker pool when dynamic shared
worker pool is implemented.Signed-off-by: Tejun Heo
09 Jun, 2010
2 commits
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Currently, when a cpu goes down, cpu_active is cleared before
CPU_DOWN_PREPARE starts and cpuset configuration is updated from a
default priority cpu notifier. When a cpu is coming up, it's set
before CPU_ONLINE but cpuset configuration again is updated from the
same cpu notifier.For cpu notifiers, this presents an inconsistent state. Threads which
a CPU_DOWN_PREPARE notifier expects to be bound to the CPU can be
migrated to other cpus because the cpu is no more inactive.Fix it by updating cpu_active in the highest priority cpu notifier and
cpuset configuration in the second highest when a cpu is coming up.
Down path is updated similarly. This guarantees that all other cpu
notifiers see consistent cpu_active and cpuset configuration.cpuset_track_online_cpus() notifier is converted to
cpuset_update_active_cpus() which just updates the configuration and
now called from cpuset_cpu_[in]active() notifiers registered from
sched_init_smp(). If cpuset is disabled, cpuset_update_active_cpus()
degenerates into partition_sched_domains() making separate notifier
for !CONFIG_CPUSETS unnecessary.This problem is triggered by cmwq. During CPU_DOWN_PREPARE, hotplug
callback creates a kthread and kthread_bind()s it to the target cpu,
and the thread is expected to run on that cpu.* Ingo's test discovered __cpuinit/exit markups were incorrect.
Fixed.Signed-off-by: Tejun Heo
Acked-by: Peter Zijlstra
Cc: Rusty Russell
Cc: Ingo Molnar
Cc: Paul Menage -
Instead of hardcoding priority 10 and 20 in sched and perf, collect
them into CPU_PRI_* enums.Signed-off-by: Tejun Heo
Acked-by: Peter Zijlstra
Cc: Rusty Russell
Cc: Paul Mackerras
Cc: Ingo Molnar
Cc: Arnaldo Carvalho de Melo
09 Dec, 2009
2 commits
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Currently the cpu-allocation/deallocation process comprises of two steps:
- Set the indicators and to update the device tree with DLPAR node
information.- Online/offline the allocated/deallocated CPU.
This is achieved by writing to the sysfs tunables "probe" during allocation
and "release" during deallocation.At the sametime, the userspace can independently online/offline the CPUs of
the system using the sysfs tunable "online".It is quite possible that when a userspace tool offlines a CPU
for the purpose of deallocation and is in the process of updating the device
tree, some other userspace tool could bring the CPU back online by writing to
the "online" sysfs tunable thereby causing the deallocate process to fail.The solution to this is to serialize writes to the "probe/release" sysfs
tunable with the writes to the "online" sysfs tunable.This patch employs a mutex to provide this serialization, which is a no-op on
all architectures except PPC_PSERIESSigned-off-by: Gautham R Shenoy
Acked-by: Vaidyanathan Srinivasan
Signed-off-by: Benjamin Herrenschmidt -
Version 3 of this patch is updated with documentation added to
Documentation/ABI. There are no changes to any of the C code from v2
of the patch.In order to support kernel DLPAR of CPU resources we need to provide an
interface to add (probe) and remove (release) the resource from the system.
This patch Creates new generic probe and release sysfs files to facilitate
cpu probe/release. The probe/release interface provides for allowing each
arch to supply their own routines for implementing the backend of adding
and removing cpus to/from the system.This also creates the powerpc specific stubs to handle the arch callouts
from writes to the sysfs files.The creation and use of these files is regulated by the
CONFIG_ARCH_CPU_PROBE_RELEASE option so that only architectures that need the
capability will have the files created.Signed-off-by: Nathan Fontenot
Signed-off-by: Benjamin Herrenschmidt
16 Aug, 2009
1 commit
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This patch introduces a new cpu_notifier() API that is similar
to hotcpu_notifier(), but which also notifies of CPUs coming
online during boot in the !HOTPLUG_CPU case.Reported-by: Ingo Molnar
Reported-by: Hugh Dickins
Tested-by: Hugh Dickins
Signed-off-by: Paul E. McKenney
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: josht@linux.vnet.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: benh@kernel.crashing.org
LKML-Reference:
Signed-off-by: Ingo Molnar
23 Jun, 2009
1 commit
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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: Sachin Sant
Tested-by: James Bottomley
Tested-by: Benjamin Herrenschmidt
Signed-off-by: Linus Torvalds
03 Apr, 2009
1 commit
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cpuhotplug_mutex_lock() is not used, remove it.
Signed-off-by: Lai Jiangshan
Cc: Ingo Molnar
Cc: Rusty Russell
Acked-by: Gautham R Shenoy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
09 Sep, 2008
1 commit
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Right now, there is no notifier that is called on a new cpu, before the new
cpu begins processing interrupts/softirqs.
Various kernel function would need that notification, e.g. kvm works around
by calling smp_call_function_single(), rcu polls cpu_online_map.The patch adds a CPU_STARTING notification. It also adds a helper function
that sends the message to all cpu_chain handlers.Tested on x86-64.
All other archs are untested. Especially on sparc, I'm not sure if I got
it right.Signed-off-by: Manfred Spraul
Signed-off-by: Ingo Molnar
26 Jul, 2008
1 commit
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workqueue_cpu_callback(CPU_DEAD) flushes cwq->thread under
cpu_maps_update_begin(). This means that the multithreaded workqueues
can't use get_online_cpus() due to the possible deadlock, very bad and
very old problem.Introduce the new state, CPU_POST_DEAD, which is called after
cpu_hotplug_done() but before cpu_maps_update_done().Change workqueue_cpu_callback() to use CPU_POST_DEAD instead of CPU_DEAD.
This means that create/destroy functions can't rely on get_online_cpus()
any longer and should take cpu_add_remove_lock instead.[akpm@linux-foundation.org: fix CONFIG_SMP=n]
Signed-off-by: Oleg Nesterov
Acked-by: Gautham R Shenoy
Cc: Heiko Carstens
Cc: Max Krasnyansky
Cc: Paul Jackson
Cc: Paul Menage
Cc: Peter Zijlstra
Cc: Vegard Nossum
Cc: Martin Schwidefsky
Cc: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Apr, 2008
1 commit
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Fix following warnings:
WARNING: vmlinux.o(.data+0x5020): Section mismatch in reference from the variable cpu_vsyscall_notifier_nb.12876 to the function .cpuinit.text:cpu_vsyscall_notifier()
WARNING: vmlinux.o(.data+0x9ce0): Section mismatch in reference from the variable profile_cpu_callback_nb.17654 to the function .devinit.text:profile_cpu_callback()
WARNING: vmlinux.o(.data+0xd380): Section mismatch in reference from the variable workqueue_cpu_callback_nb.15004 to the function .devinit.text:workqueue_cpu_callback()
WARNING: vmlinux.o(.data+0x11d00): Section mismatch in reference from the variable relay_hotcpu_callback_nb.19626 to the function .cpuinit.text:relay_hotcpu_callback()
WARNING: vmlinux.o(.data+0x12970): Section mismatch in reference from the variable cpu_callback_nb.24694 to the function .devinit.text:cpu_callback()
WARNING: vmlinux.o(.data+0x3fee0): Section mismatch in reference from the variable percpu_counter_hotcpu_callback_nb.10903 to the function .cpuinit.text:percpu_counter_hotcpu_callback()
WARNING: vmlinux.o(.data+0x74ce0): Section mismatch in reference from the variable topology_cpu_callback_nb.12506 to the function .cpuinit.text:topology_cpu_callback()Functions used as argument are by definition only used in HOTPLUG_CPU
situations so thay are annotated __cpuinit. Annotate the static variable used
by hotcpu_register with __cpuinitdata to match this definition.Signed-off-by: Sam Ravnborg
Cc: Gautham R Shenoy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
19 Apr, 2008
1 commit
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None of these files use any of the functionality promised by
asm/semaphore.h. It's possible that they (or some user of them) rely
on it dragging in some unrelated header file, but I can't build all
these files, so we'll have to fix any build failures as they come up.Signed-off-by: Matthew Wilcox
26 Jan, 2008
1 commit
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fix build on !CONFIG_SMP.
Signed-off-by: Ingo Molnar
