The copy_to_user() call returns the number of bytes remaining but we
want to return -EFAULT on error.
Fixes "x32: fix waitid()"
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The IRQ_EXIT_OFFSET trick was used to make sure the irq
doesn't get preempted after we substract the HARDIRQ_OFFSET
until we are entirely done with any code in irq_exit().
This workaround was necessary because some archs may call
irq_exit() with irqs enabled and there is still some code
in the end of this function that is not covered by the
HARDIRQ_OFFSET but want to stay non-preemptible.
Now that irq are always disabled in irq_exit(), the whole code
is guaranteed not to be preempted. We can thus remove this hack.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
A large number of cleanups, all over the platforms. This is dominated
largely by the Samsung platforms (s3c, s5p, exynos) and a few of the
others moving code out of arch/arm into more appropriate subsystems.
The clocksource and irqchip drivers are now abstracted to the point
where platforms that are already cleaned up do not need to even specify
the driver they use, it can all get configured from the device tree
as we do for normal device drivers. The clocksource changes basically
touch every single platform in the process.
We further clean up the use of platform specific header files here,
with the goal of turning more of the platforms over to being
"multiplatform" enabled, which implies that they cannot expose
their headers to architecture independent code any more.
It is expected that no functional changes are part of the cleanup.
The overall reduction in total code lines is mostly the result of
removing broken and obsolete code.
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Merge tag 'cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC cleanups from Arnd Bergmann:
"A large number of cleanups, all over the platforms. This is dominated
largely by the Samsung platforms (s3c, s5p, exynos) and a few of the
others moving code out of arch/arm into more appropriate subsystems.
The clocksource and irqchip drivers are now abstracted to the point
where platforms that are already cleaned up do not need to even
specify the driver they use, it can all get configured from the device
tree as we do for normal device drivers. The clocksource changes
basically touch every single platform in the process.
We further clean up the use of platform specific header files here,
with the goal of turning more of the platforms over to being
"multiplatform" enabled, which implies that they cannot expose their
headers to architecture independent code any more.
It is expected that no functional changes are part of the cleanup.
The overall reduction in total code lines is mostly the result of
removing broken and obsolete code."
* tag 'cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (133 commits)
ARM: mvebu: correct gated clock documentation
ARM: kirkwood: add missing include for nsa310
ARM: exynos: move exynos4210-combiner to drivers/irqchip
mfd: db8500-prcmu: update resource passing
drivers/db8500-cpufreq: delete dangling include
ARM: at91: remove NEOCORE 926 board
sunxi: Cleanup the reset code and add meaningful registers defines
ARM: S3C24XX: header mach/regs-mem.h local
ARM: S3C24XX: header mach/regs-power.h local
ARM: S3C24XX: header mach/regs-s3c2412-mem.h local
ARM: S3C24XX: Remove plat-s3c24xx directory in arch/arm/
ARM: S3C24XX: transform s3c2443 subirqs into new structure
ARM: S3C24XX: modify s3c2443 irq init to initialize all irqs
ARM: S3C24XX: move s3c2443 irq code to irq.c
ARM: S3C24XX: transform s3c2416 irqs into new structure
ARM: S3C24XX: modify s3c2416 irq init to initialize all irqs
ARM: S3C24XX: move s3c2416 irq init to common irq code
ARM: S3C24XX: Modify s3c_irq_wake to use the hwirq property
ARM: S3C24XX: Move irq syscore-ops to irq-pm
clocksource: always define CLOCKSOURCE_OF_DECLARE
...
Here's the big tty/serial driver patches for 3.9-rc1.
More tty port rework and fixes from Jiri here, as well as lots of
individual serial driver updates and fixes.
All of these have been in the linux-next tree for a while.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial patches from Greg Kroah-Hartman:
"Here's the big tty/serial driver patches for 3.9-rc1.
More tty port rework and fixes from Jiri here, as well as lots of
individual serial driver updates and fixes.
All of these have been in the linux-next tree for a while."
* tag 'tty-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (140 commits)
tty: mxser: improve error handling in mxser_probe() and mxser_module_init()
serial: imx: fix uninitialized variable warning
serial: tegra: assume CONFIG_OF
TTY: do not update atime/mtime on read/write
lguest: select CONFIG_TTY to build properly.
ARM defconfigs: add missing inclusions of linux/platform_device.h
fb/exynos: include platform_device.h
ARM: sa1100/assabet: include platform_device.h directly
serial: imx: Fix recursive locking bug
pps: Fix build breakage from decoupling pps from tty
tty: Remove ancient hardpps()
pps: Additional cleanups in uart_handle_dcd_change
pps: Move timestamp read into PPS code proper
pps: Don't crash the machine when exiting will do
pps: Fix a use-after free bug when unregistering a source.
pps: Use pps_lookup_dev to reduce ldisc coupling
pps: Add pps_lookup_dev() function
tty: serial: uartlite: Support uartlite on big and little endian systems
tty: serial: uartlite: Fix sparse and checkpatch warnings
serial/arc-uart: Miscll DT related updates (Grant's review comments)
...
Fix up trivial conflicts, mostly just due to the TTY config option
clashing with the EXPERIMENTAL removal.
Here is the big driver core merge for 3.9-rc1
There are two major series here, both of which touch lots of drivers all
over the kernel, and will cause you some merge conflicts:
- add a new function called devm_ioremap_resource() to properly be
able to check return values.
- remove CONFIG_EXPERIMENTAL
If you need me to provide a merged tree to handle these resolutions,
please let me know.
Other than those patches, there's not much here, some minor fixes and
updates.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core patches from Greg Kroah-Hartman:
"Here is the big driver core merge for 3.9-rc1
There are two major series here, both of which touch lots of drivers
all over the kernel, and will cause you some merge conflicts:
- add a new function called devm_ioremap_resource() to properly be
able to check return values.
- remove CONFIG_EXPERIMENTAL
Other than those patches, there's not much here, some minor fixes and
updates"
Fix up trivial conflicts
* tag 'driver-core-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (221 commits)
base: memory: fix soft/hard_offline_page permissions
drivercore: Fix ordering between deferred_probe and exiting initcalls
backlight: fix class_find_device() arguments
TTY: mark tty_get_device call with the proper const values
driver-core: constify data for class_find_device()
firmware: Ignore abort check when no user-helper is used
firmware: Reduce ifdef CONFIG_FW_LOADER_USER_HELPER
firmware: Make user-mode helper optional
firmware: Refactoring for splitting user-mode helper code
Driver core: treat unregistered bus_types as having no devices
watchdog: Convert to devm_ioremap_resource()
thermal: Convert to devm_ioremap_resource()
spi: Convert to devm_ioremap_resource()
power: Convert to devm_ioremap_resource()
mtd: Convert to devm_ioremap_resource()
mmc: Convert to devm_ioremap_resource()
mfd: Convert to devm_ioremap_resource()
media: Convert to devm_ioremap_resource()
iommu: Convert to devm_ioremap_resource()
drm: Convert to devm_ioremap_resource()
...
This reverts commit 351429b2e62b6545bb10c756686393f29ba268a1. The
extra local_irq_save() is not longer needed as the call site now
always calls with interrupts disabled.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linuxfoundation.org>
With the irq protection in irq_exit, we can remove the #ifdeffery and
the bh_disable/enable dance in invoke_softirq()
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linuxfoundation.org>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1302202155320.22263@ionos
We had already a few problems with code called from irq_exit() when
interrupted from a nesting interrupt. This can happen on architectures
which do not define __ARCH_IRQ_EXIT_IRQS_DISABLED.
__ARCH_IRQ_EXIT_IRQS_DISABLED should go away and we want to make it
mandatory to call irq_exit() with interrupts disabled.
As a temporary protection disable interrupts for those architectures
which do not define __ARCH_IRQ_EXIT_IRQS_DISABLED and add a WARN_ONCE
when an architecture which defines __ARCH_IRQ_EXIT_IRQS_DISABLED calls
irq_exit() with interrupts enabled.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linuxfoundation.org>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1302202155320.22263@ionos
As it stands, irq_exit() may or may not be called with
irqs disabled, depending on __ARCH_IRQ_EXIT_IRQS_DISABLED
that the arch can define.
It makes tick_nohz_irq_exit() unsafe. For example two
interrupts can race in tick_nohz_stop_sched_tick(): the inner
most one computes the expiring time on top of the timer list,
then it's interrupted right before reprogramming the
clock. The new interrupt enqueues a new timer list timer,
it reprogram the clock to take it into account and it exits.
The CPUs resumes the inner most interrupt and performs the clock
reprogramming without considering the new timer list timer.
This regression has been introduced by:
280f06774a
("nohz: Separate out irq exit and idle loop dyntick logic")
Let's fix it right now with the appropriate protections.
A saner long term solution will be to remove
__ARCH_IRQ_EXIT_IRQS_DISABLED and mandate that irq_exit() is called
with interrupts disabled.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linuxfoundation.org>
Cc: <stable@vger.kernel.org> #v3.2+
Link: http://lkml.kernel.org/r/1361373336-11337-1-git-send-email-fweisbec@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
When idr_find() was fed a negative ID, it used to look up the ID
ignoring the sign bit before recent ("idr: remove MAX_IDR_MASK and
move left MAX_IDR_* into idr.c") patch. Now a negative ID triggers
a WARN_ON_ONCE().
__lock_timer() feeds timer_id from userland directly to idr_find()
without sanitizing it which can trigger the above malfunctions. Add a
range check on @timer_id before invoking idr_find() in __lock_timer().
While timer_t is defined as int by all archs at the moment, Andrew
worries that it may be defined as a larger type later on. Make the
test cover larger integers too so that it at least is guaranteed to
not return the wrong timer.
Note that WARN_ON_ONCE() in idr_find() on id < 0 is transitional
precaution while moving away from ignoring MSB. Once it's gone we can
remove the guard as long as timer_t isn't larger than int.
Signed-off-by: Tejun Heo <tj@kernel.org>nnn
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20130220232412.GL3570@htj.dyndns.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pull networking update from David Miller:
1) Checkpoint/restarted TCP sockets now can properly propagate the TCP
timestamp offset. From Andrey Vagin.
2) VMWARE VM VSOCK layer, from Andy King.
3) Much improved support for virtual functions and SR-IOV in bnx2x,
from Ariel ELior.
4) All protocols on ipv4 and ipv6 are now network namespace aware, and
all the compatability checks for initial-namespace-only protocols is
removed. Thanks to Tom Parkin for helping deal with the last major
holdout, L2TP.
5) IPV6 support in netpoll and network namespace support in pktgen,
from Cong Wang.
6) Multiple Registration Protocol (MRP) and Multiple VLAN Registration
Protocol (MVRP) support, from David Ward.
7) Compute packet lengths more accurately in the packet scheduler, from
Eric Dumazet.
8) Use per-task page fragment allocator in skb_append_datato_frags(),
also from Eric Dumazet.
9) Add support for connection tracking labels in netfilter, from
Florian Westphal.
10) Fix default multicast group joining on ipv6, and add anti-spoofing
checks to 6to4 and 6rd. From Hannes Frederic Sowa.
11) Make ipv4/ipv6 fragmentation memory limits more reasonable in modern
times, rearrange inet frag datastructures for better cacheline
locality, and move more operations outside of locking. From Jesper
Dangaard Brouer.
12) Instead of strict master <--> slave relationships, allow arbitrary
scenerios with "upper device lists". From Jiri Pirko.
13) Improve rate limiting accuracy in TBF and act_police, also from Jiri
Pirko.
14) Add a BPF filter netfilter match target, from Willem de Bruijn.
15) Orphan and delete a bunch of pre-historic networking drivers from
Paul Gortmaker.
16) Add TSO support for GRE tunnels, from Pravin B SHelar. Although
this still needs some minor bug fixing before it's %100 correct in
all cases.
17) Handle unresolved IPSEC states like ARP, with a resolution packet
queue. From Steffen Klassert.
18) Remove TCP Appropriate Byte Count support (ABC), from Stephen
Hemminger. This was long overdue.
19) Support SO_REUSEPORT, from Tom Herbert.
20) Allow locking a socket BPF filter, so that it cannot change after a
process drops capabilities.
21) Add VLAN filtering to bridge, from Vlad Yasevich.
22) Bring ipv6 on-par with ipv4 and do not cache neighbour entries in
the ipv6 routes, from YOSHIFUJI Hideaki.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1538 commits)
ipv6: fix race condition regarding dst->expires and dst->from.
net: fix a wrong assignment in skb_split()
ip_gre: remove an extra dst_release()
ppp: set qdisc_tx_busylock to avoid LOCKDEP splat
atl1c: restore buffer state
net: fix a build failure when !CONFIG_PROC_FS
net: ipv4: fix waring -Wunused-variable
net: proc: fix build failed when procfs is not configured
Revert "xen: netback: remove redundant xenvif_put"
net: move procfs code to net/core/net-procfs.c
qmi_wwan, cdc-ether: add ADU960S
bonding: set sysfs device_type to 'bond'
bonding: fix bond_release_all inconsistencies
b44: use netdev_alloc_skb_ip_align()
xen: netback: remove redundant xenvif_put
net: fec: Do a sanity check on the gpio number
ip_gre: propogate target device GSO capability to the tunnel device
ip_gre: allow CSUM capable devices to handle packets
bonding: Fix initialize after use for 3ad machine state spinlock
bonding: Fix race condition between bond_enslave() and bond_3ad_update_lacp_rate()
...
- Rework of the ACPI namespace scanning code from Rafael J. Wysocki
with contributions from Bjorn Helgaas, Jiang Liu, Mika Westerberg,
Toshi Kani, and Yinghai Lu.
- ACPI power resources handling and ACPI device PM update from
Rafael J. Wysocki.
- ACPICA update to version 20130117 from Bob Moore and Lv Zheng
with contributions from Aaron Lu, Chao Guan, Jesper Juhl, and
Tim Gardner.
- Support for Intel Lynxpoint LPSS from Mika Westerberg.
- cpuidle update from Len Brown including Intel Haswell support, C1
state for intel_idle, removal of global pm_idle.
- cpuidle fixes and cleanups from Daniel Lezcano.
- cpufreq fixes and cleanups from Viresh Kumar and Fabio Baltieri
with contributions from Stratos Karafotis and Rickard Andersson.
- Intel P-states driver for Sandy Bridge processors from
Dirk Brandewie.
- cpufreq driver for Marvell Kirkwood SoCs from Andrew Lunn.
- cpufreq fixes related to ordering issues between acpi-cpufreq and
powernow-k8 from Borislav Petkov and Matthew Garrett.
- cpufreq support for Calxeda Highbank processors from Mark Langsdorf
and Rob Herring.
- cpufreq driver for the Freescale i.MX6Q SoC and cpufreq-cpu0 update
from Shawn Guo.
- cpufreq Exynos fixes and cleanups from Jonghwan Choi, Sachin Kamat,
and Inderpal Singh.
- Support for "lightweight suspend" from Zhang Rui.
- Removal of the deprecated power trace API from Paul Gortmaker.
- Assorted updates from Andreas Fleig, Colin Ian King,
Davidlohr Bueso, Joseph Salisbury, Kees Cook, Li Fei,
Nishanth Menon, ShuoX Liu, Srinivas Pandruvada, Tejun Heo,
Thomas Renninger, and Yasuaki Ishimatsu.
/
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Merge tag 'pm+acpi-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI and power management updates from Rafael Wysocki:
- Rework of the ACPI namespace scanning code from Rafael J. Wysocki
with contributions from Bjorn Helgaas, Jiang Liu, Mika Westerberg,
Toshi Kani, and Yinghai Lu.
- ACPI power resources handling and ACPI device PM update from Rafael
J Wysocki.
- ACPICA update to version 20130117 from Bob Moore and Lv Zheng with
contributions from Aaron Lu, Chao Guan, Jesper Juhl, and Tim Gardner.
- Support for Intel Lynxpoint LPSS from Mika Westerberg.
- cpuidle update from Len Brown including Intel Haswell support, C1
state for intel_idle, removal of global pm_idle.
- cpuidle fixes and cleanups from Daniel Lezcano.
- cpufreq fixes and cleanups from Viresh Kumar and Fabio Baltieri with
contributions from Stratos Karafotis and Rickard Andersson.
- Intel P-states driver for Sandy Bridge processors from Dirk
Brandewie.
- cpufreq driver for Marvell Kirkwood SoCs from Andrew Lunn.
- cpufreq fixes related to ordering issues between acpi-cpufreq and
powernow-k8 from Borislav Petkov and Matthew Garrett.
- cpufreq support for Calxeda Highbank processors from Mark Langsdorf
and Rob Herring.
- cpufreq driver for the Freescale i.MX6Q SoC and cpufreq-cpu0 update
from Shawn Guo.
- cpufreq Exynos fixes and cleanups from Jonghwan Choi, Sachin Kamat,
and Inderpal Singh.
- Support for "lightweight suspend" from Zhang Rui.
- Removal of the deprecated power trace API from Paul Gortmaker.
- Assorted updates from Andreas Fleig, Colin Ian King, Davidlohr Bueso,
Joseph Salisbury, Kees Cook, Li Fei, Nishanth Menon, ShuoX Liu,
Srinivas Pandruvada, Tejun Heo, Thomas Renninger, and Yasuaki
Ishimatsu.
* tag 'pm+acpi-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (267 commits)
PM idle: remove global declaration of pm_idle
unicore32 idle: delete stray pm_idle comment
openrisc idle: delete pm_idle
mn10300 idle: delete pm_idle
microblaze idle: delete pm_idle
m32r idle: delete pm_idle, and other dead idle code
ia64 idle: delete pm_idle
cris idle: delete idle and pm_idle
ARM64 idle: delete pm_idle
ARM idle: delete pm_idle
blackfin idle: delete pm_idle
sparc idle: rename pm_idle to sparc_idle
sh idle: rename global pm_idle to static sh_idle
x86 idle: rename global pm_idle to static x86_idle
APM idle: register apm_cpu_idle via cpuidle
cpufreq / intel_pstate: Add kernel command line option disable intel_pstate.
cpufreq / intel_pstate: Change to disallow module build
tools/power turbostat: display SMI count by default
intel_idle: export both C1 and C1E
ACPI / hotplug: Fix concurrency issues and memory leaks
...
Pull cpuset changes from Tejun Heo:
- Synchornization has seen a lot of changes with focus on decoupling
cpuset synchronization from cgroup internal locking.
After this change, there only remain a couple of mostly trivial
dependencies on cgroup_lock outside cgroup core proper. cgroup_lock
is scheduled to be unexported in this devel cycle.
This will finally remove the fragile locking order around cgroup
(cgroup locking wants to / should be one of the outermost but yet has
been acquired from deep inside individual controllers).
- At this point, Li is most knowlegeable with cpuset and taking over
the maintainership of cpuset.
* 'for-3.9-cpuset' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cpuset: drop spurious retval assignment in proc_cpuset_show()
cpuset: fix RCU lockdep splat
cpuset: update MAINTAINERS
cpuset: remove cpuset->parent
cpuset: replace cpuset->stack_list with cpuset_for_each_descendant_pre()
cpuset: replace cgroup_mutex locking with cpuset internal locking
cpuset: schedule hotplug propagation from cpuset_attach() if the cpuset is empty
cpuset: pin down cpus and mems while a task is being attached
cpuset: make CPU / memory hotplug propagation asynchronous
cpuset: drop async_rebuild_sched_domains()
cpuset: don't nest cgroup_mutex inside get_online_cpus()
cpuset: reorganize CPU / memory hotplug handling
cpuset: cleanup cpuset[_can]_attach()
cpuset: introduce cpuset_for_each_child()
cpuset: introduce CS_ONLINE
cpuset: introduce ->css_on/offline()
cpuset: remove fast exit path from remove_tasks_in_empty_cpuset()
cpuset: remove unused cpuset_unlock()
Pull cgroup changes from Tejun Heo:
"Nothing too drastic.
- Removal of synchronize_rcu() from userland visible paths.
- Various fixes and cleanups from Li.
- cgroup_rightmost_descendant() added which will be used by cpuset
changes (it will be a separate pull request)."
* 'for-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: fail if monitored file and event_control are in different cgroup
cgroup: fix cgroup_rmdir() vs close(eventfd) race
cpuset: fix cpuset_print_task_mems_allowed() vs rename() race
cgroup: fix exit() vs rmdir() race
cgroup: remove bogus comments in cgroup_diput()
cgroup: remove synchronize_rcu() from cgroup_diput()
cgroup: remove duplicate RCU free on struct cgroup
sched: remove redundant NULL cgroup check in task_group_path()
sched: split out css_online/css_offline from tg creation/destruction
cgroup: initialize cgrp->dentry before css_alloc()
cgroup: remove a NULL check in cgroup_exit()
cgroup: fix bogus kernel warnings when cgroup_create() failed
cgroup: remove synchronize_rcu() from rebind_subsystems()
cgroup: remove synchronize_rcu() from cgroup_attach_{task|proc}()
cgroup: use new hashtable implementation
cgroups: fix cgroup_event_listener error handling
cgroups: move cgroup_event_listener.c to tools/cgroup
cgroup: implement cgroup_rightmost_descendant()
cgroup: remove unused dummy cgroup_fork_callbacks()
Pull async changes from Tejun Heo:
"These are followups for the earlier deadlock issue involving async
ending up waiting for itself through block requesting module[1]. The
following changes are made by these commits.
- Instead of requesting default elevator on each request_queue init,
block now requests it once early during boot.
- Kmod triggers warning if invoked from an async worker.
- Async synchronization implementation has been reimplemented. It's
a lot simpler now."
* 'for-3.9-async' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
async: initialise list heads to fix crash
async: replace list of active domains with global list of pending items
async: keep pending tasks on async_domain and remove async_pending
async: use ULLONG_MAX for infinity cookie value
async: bring sanity to the use of words domain and running
async, kmod: warn on synchronous request_module() from async workers
block: don't request module during elevator init
init, block: try to load default elevator module early during boot
Pull workqueue changes from Tejun Heo:
"A lot of reorganization is going on mostly to prepare for worker pools
with custom attributes so that workqueue can replace custom pool
implementations in places including writeback and btrfs and make CPU
assignment in crypto more flexible.
workqueue evolved from purely per-cpu design and implementation, so
there are a lot of assumptions regarding being bound to CPUs and even
unbound workqueues are implemented as an extension of the model -
workqueues running on the special unbound CPU. Bulk of changes this
round are about promoting worker_pools as the top level abstraction
replacing global_cwq (global cpu workqueue). At this point, I'm
fairly confident about getting custom worker pools working pretty soon
and ready for the next merge window.
Lai's patches are replacing the convoluted mb() dancing workqueue has
been doing with much simpler mechanism which only depends on
assignment atomicity of long. For details, please read the commit
message of 0b3dae68ac ("workqueue: simplify is-work-item-queued-here
test"). While the change ends up adding one pointer to struct
delayed_work, the inflation in percentage is less than five percent
and it decouples delayed_work logic a lot more cleaner from usual work
handling, removes the unusual memory barrier dancing, and allows for
further simplification, so I think the trade-off is acceptable.
There will be two more workqueue related pull requests and there are
some shared commits among them. I'll write further pull requests
assuming this pull request is pulled first."
* 'for-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (37 commits)
workqueue: un-GPL function delayed_work_timer_fn()
workqueue: rename cpu_workqueue to pool_workqueue
workqueue: reimplement is_chained_work() using current_wq_worker()
workqueue: fix is_chained_work() regression
workqueue: pick cwq instead of pool in __queue_work()
workqueue: make get_work_pool_id() cheaper
workqueue: move nr_running into worker_pool
workqueue: cosmetic update in try_to_grab_pending()
workqueue: simplify is-work-item-queued-here test
workqueue: make work->data point to pool after try_to_grab_pending()
workqueue: add delayed_work->wq to simplify reentrancy handling
workqueue: make work_busy() test WORK_STRUCT_PENDING first
workqueue: replace WORK_CPU_NONE/LAST with WORK_CPU_END
workqueue: post global_cwq removal cleanups
workqueue: rename nr_running variables
workqueue: remove global_cwq
workqueue: remove worker_pool->gcwq
workqueue: replace for_each_worker_pool() with for_each_std_worker_pool()
workqueue: make freezing/thawing per-pool
workqueue: make hotplug processing per-pool
...
Pull workqueue [delayed_]work_pending() cleanups from Tejun Heo:
"This is part of on-going cleanups to remove / minimize usages of
workqueue interfaces which are deprecated and/or misleading.
This round drops a number of usages of [delayed_]work_pending(), which
are dangerous as they lack any form of synchronization and thus often
lead to buggy / unnecessary code. There are a couple legitimate use
cases in kernel. Hopefully, they can be converted and
[delayed_]work_pending() can be removed completely. Even if not,
removing most of misuses should make it more difficult to find
examples of misuses and thus slow down growth of them.
These changes are independent from other workqueue changes."
* 'for-3.9-cleanups' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
wimax/i2400m: fix i2400m->wake_tx_skb handling
kprobes: fix wait_for_kprobe_optimizer()
ipw2x00: simplify scan_event handling
video/exynos: don't use [delayed_]work_pending()
tty/max3100: don't use [delayed_]work_pending()
x86/mce: don't use [delayed_]work_pending()
rfkill: don't use [delayed_]work_pending()
wl1251: don't use [delayed_]work_pending()
thinkpad_acpi: don't use [delayed_]work_pending()
mwifiex: don't use [delayed_]work_pending()
sja1000: don't use [delayed_]work_pending()
Pull two x86 kernel build changes from Ingo Molnar:
"The first change modifies how 'make oldconfig' works on cross-bitness
situations on x86. It was felt the new behavior of preserving the
bitness of the .config is more logical. This is a leftover of the
merge.
The second change eliminates a Perl warning. (There's another, more
complete fix resulting of this warning fix, which second fix in flight
to you via the kbuild tree, which will remove the timeconst.pl script
altogether.)"
* 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timeconst.pl: Eliminate Perl warning
x86: Default to ARCH=x86 to avoid overriding CONFIG_64BIT
Pull x86/apic changes from Ingo Molnar:
"Main changes:
- Multiple MSI support added to the APIC, PCI and AHCI code - acked
by all relevant maintainers, by Alexander Gordeev.
The advantage is that multiple AHCI ports can have multiple MSI
irqs assigned, and can thus spread to multiple CPUs.
[ Drivers can make use of this new facility via the
pci_enable_msi_block_auto() method ]
- x86 IOAPIC code from interrupt remapping cleanups from Joerg
Roedel:
These patches move all interrupt remapping specific checks out of
the x86 core code and replaces the respective call-sites with
function pointers. As a result the interrupt remapping code is
better abstraced from x86 core interrupt handling code.
- Various smaller improvements, fixes and cleanups."
* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits)
x86/intel/irq_remapping: Clean up x2apic opt-out security warning mess
x86, kvm: Fix intialization warnings in kvm.c
x86, irq: Move irq_remapped out of x86 core code
x86, io_apic: Introduce eoi_ioapic_pin call-back
x86, msi: Introduce x86_msi.compose_msi_msg call-back
x86, irq: Introduce setup_remapped_irq()
x86, irq: Move irq_remapped() check into free_remapped_irq
x86, io-apic: Remove !irq_remapped() check from __target_IO_APIC_irq()
x86, io-apic: Move CONFIG_IRQ_REMAP code out of x86 core
x86, irq: Add data structure to keep AMD specific irq remapping information
x86, irq: Move irq_remapping_enabled declaration to iommu code
x86, io_apic: Remove irq_remapping_enabled check in setup_timer_IRQ0_pin
x86, io_apic: Move irq_remapping_enabled checks out of check_timer()
x86, io_apic: Convert setup_ioapic_entry to function pointer
x86, io_apic: Introduce set_affinity function pointer
x86, msi: Use IRQ remapping specific setup_msi_irqs routine
x86, hpet: Introduce x86_msi_ops.setup_hpet_msi
x86, io_apic: Introduce x86_io_apic_ops.print_entries for debugging
x86, io_apic: Introduce x86_io_apic_ops.disable()
x86, apic: Mask IO-APIC and PIC unconditionally on LAPIC resume
...
Pull timer changes from Ingo Molnar:
"Main changes:
- ntp: Add CONFIG_RTC_SYSTOHC: a generic RTC driver facility
complementing the existing CONFIG_RTC_HCTOSYS, which uses NTP to
keep the hardware clock updated.
- posix-timers: Fix clock_adjtime to always return timex data on
success. This is changing the ABI, but no breakage was expected
and found - caution is warranted nevertheless.
- platform persistent clock improvements/cleanups.
- clockevents: refactor timer broadcast handling to be more generic
and less duplicated with matching architecture code (mostly ARM
motivated.)
- various fixes and cleanups"
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timers/x86/hpet: Use HPET_COUNTER to specify the hpet counter in vread_hpet()
posix-cpu-timers: Fix nanosleep task_struct leak
clockevents: Fix generic broadcast for FEAT_C3STOP
time, Fix setting of hardware clock in NTP code
hrtimer: Prevent hrtimer_enqueue_reprogram race
clockevents: Add generic timer broadcast function
clockevents: Add generic timer broadcast receiver
timekeeping: Switch HAS_PERSISTENT_CLOCK to ALWAYS_USE_PERSISTENT_CLOCK
x86/time/rtc: Don't print extended CMOS year when reading RTC
x86: Select HAS_PERSISTENT_CLOCK on x86
timekeeping: Add CONFIG_HAS_PERSISTENT_CLOCK option
rtc: Skip the suspend/resume handling if persistent clock exist
timekeeping: Add persistent_clock_exist flag
posix-timers: Fix clock_adjtime to always return timex data on success
Round the calculated scale factor in set_cyc2ns_scale()
NTP: Add a CONFIG_RTC_SYSTOHC configuration
MAINTAINERS: Update John Stultz's email
time: create __getnstimeofday for WARNless calls
Pull preparatory smp/hotplug patches from Ingo Molnar:
"Some early preparatory changes for the WIP hotplug rework by Thomas
Gleixner."
* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
stop_machine: Use smpboot threads
stop_machine: Store task reference in a separate per cpu variable
smpboot: Allow selfparking per cpu threads
Pull scheduler changes from Ingo Molnar:
"Main changes:
- scheduler side full-dynticks (user-space execution is undisturbed
and receives no timer IRQs) preparation changes that convert the
cputime accounting code to be full-dynticks ready, from Frederic
Weisbecker.
- Initial sched.h split-up changes, by Clark Williams
- select_idle_sibling() performance improvement by Mike Galbraith:
" 1 tbench pair (worst case) in a 10 core + SMT package:
pre 15.22 MB/sec 1 procs
post 252.01 MB/sec 1 procs "
- sched_rr_get_interval() ABI fix/change. We think this detail is not
used by apps (so it's not an ABI in practice), but lets keep it
under observation.
- misc RT scheduling cleanups, optimizations"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
sched/rt: Add <linux/sched/rt.h> header to <linux/init_task.h>
cputime: Remove irqsave from seqlock readers
sched, powerpc: Fix sched.h split-up build failure
cputime: Restore CPU_ACCOUNTING config defaults for PPC64
sched/rt: Move rt specific bits into new header file
sched/rt: Add a tuning knob to allow changing SCHED_RR timeslice
sched: Move sched.h sysctl bits into separate header
sched: Fix signedness bug in yield_to()
sched: Fix select_idle_sibling() bouncing cow syndrome
sched/rt: Further simplify pick_rt_task()
sched/rt: Do not account zero delta_exec in update_curr_rt()
cputime: Safely read cputime of full dynticks CPUs
kvm: Prepare to add generic guest entry/exit callbacks
cputime: Use accessors to read task cputime stats
cputime: Allow dynamic switch between tick/virtual based cputime accounting
cputime: Generic on-demand virtual cputime accounting
cputime: Move default nsecs_to_cputime() to jiffies based cputime file
cputime: Librarize per nsecs resolution cputime definitions
cputime: Avoid multiplication overflow on utime scaling
context_tracking: Export context state for generic vtime
...
Fix up conflict in kernel/context_tracking.c due to comment additions.
Pull perf changes from Ingo Molnar:
"There are lots of improvements, the biggest changes are:
Main kernel side changes:
- Improve uprobes performance by adding 'pre-filtering' support, by
Oleg Nesterov.
- Make some POWER7 events available in sysfs, equivalent to what was
done on x86, from Sukadev Bhattiprolu.
- tracing updates by Steve Rostedt - mostly misc fixes and smaller
improvements.
- Use perf/event tracing to report PCI Express advanced errors, by
Tony Luck.
- Enable northbridge performance counters on AMD family 15h, by Jacob
Shin.
- This tracing commit:
tracing: Remove the extra 4 bytes of padding in events
changes the ABI. All involved parties (PowerTop in particular)
seem to agree that it's safe to do now with the introduction of
libtraceevent, but the devil is in the details ...
Main tooling side changes:
- Add 'event group view', from Namyung Kim:
To use it, 'perf record' should group events when recording. And
then perf report parses the saved group relation from file header
and prints them together if --group option is provided. You can
use the 'perf evlist' command to see event group information:
$ perf record -e '{ref-cycles,cycles}' noploop 1
[ perf record: Woken up 2 times to write data ]
[ perf record: Captured and wrote 0.385 MB perf.data (~16807 samples) ]
$ perf evlist --group
{ref-cycles,cycles}
With this example, default perf report will show you each event
separately.
You can use --group option to enable event group view:
$ perf report --group
...
# group: {ref-cycles,cycles}
# ========
# Samples: 7K of event 'anon group { ref-cycles, cycles }'
# Event count (approx.): 6876107743
#
# Overhead Command Shared Object Symbol
# ................ ....... ................. ..........................
99.84% 99.76% noploop noploop [.] main
0.07% 0.00% noploop ld-2.15.so [.] strcmp
0.03% 0.00% noploop [kernel.kallsyms] [k] timerqueue_del
0.03% 0.03% noploop [kernel.kallsyms] [k] sched_clock_cpu
0.02% 0.00% noploop [kernel.kallsyms] [k] account_user_time
0.01% 0.00% noploop [kernel.kallsyms] [k] __alloc_pages_nodemask
0.00% 0.00% noploop [kernel.kallsyms] [k] native_write_msr_safe
0.00% 0.11% noploop [kernel.kallsyms] [k] _raw_spin_lock
0.00% 0.06% noploop [kernel.kallsyms] [k] find_get_page
0.00% 0.02% noploop [kernel.kallsyms] [k] rcu_check_callbacks
0.00% 0.02% noploop [kernel.kallsyms] [k] __current_kernel_time
As you can see the Overhead column now contains both of ref-cycles
and cycles and header line shows group information also - 'anon
group { ref-cycles, cycles }'. The output is sorted by period of
group leader first.
- Initial GTK+ annotate browser, from Namhyung Kim.
- Add option for runtime switching perf data file in perf report,
just press 's' and a menu with the valid files found in the current
directory will be presented, from Feng Tang.
- Add support to display whole group data for raw columns, from Jiri
Olsa.
- Add per processor socket count aggregation in perf stat, from
Stephane Eranian.
- Add interval printing in 'perf stat', from Stephane Eranian.
- 'perf test' improvements
- Add support for wildcards in tracepoint system name, from Jiri
Olsa.
- Add anonymous huge page recognition, from Joshua Zhu.
- perf build-id cache now can show DSOs present in a perf.data file
that are not in the cache, to integrate with build-id servers being
put in place by organizations such as Fedora.
- perf top now shares more of the evsel config/creation routines with
'record', paving the way for further integration like 'top'
snapshots, etc.
- perf top now supports DWARF callchains.
- Fix mmap limitations on 32-bit, fix from David Miller.
- 'perf bench numa mem' NUMA performance measurement suite
- ... and lots of fixes, performance improvements, cleanups and other
improvements I failed to list - see the shortlog and git log for
details."
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (270 commits)
perf/x86/amd: Enable northbridge performance counters on AMD family 15h
perf/hwbp: Fix cleanup in case of kzalloc failure
perf tools: Fix build with bison 2.3 and older.
perf tools: Limit unwind support to x86 archs
perf annotate: Make it to be able to skip unannotatable symbols
perf gtk/annotate: Fail early if it can't annotate
perf gtk/annotate: Show source lines with gray color
perf gtk/annotate: Support multiple event annotation
perf ui/gtk: Implement basic GTK2 annotation browser
perf annotate: Fix warning message on a missing vmlinux
perf buildid-cache: Add --update option
uprobes/perf: Avoid uprobe_apply() whenever possible
uprobes/perf: Teach trace_uprobe/perf code to use UPROBE_HANDLER_REMOVE
uprobes/perf: Teach trace_uprobe/perf code to pre-filter
uprobes/perf: Teach trace_uprobe/perf code to track the active perf_event's
uprobes: Introduce uprobe_apply()
perf: Introduce hw_perf_event->tp_target and ->tp_list
uprobes/perf: Always increment trace_uprobe->nhit
uprobes/tracing: Kill uprobe_trace_consumer, embed uprobe_consumer into trace_uprobe
uprobes/tracing: Introduce is_trace_uprobe_enabled()
...
Pull irq core changes from Ingo Molnar:
"The biggest changes are the IRQ-work and printk changes from Frederic
Weisbecker, which prepare the code for 'full dynticks' (the ability to
stop or slow down the periodic tick arbitrarily, not just in idle time
as today):
- Don't stop tick with irq works pending. This fix is generally
useful and concerns archs that can't raise self IPIs.
- Flush irq works before CPU offlining.
- Introduce "lazy" irq works that can wait for the next tick to be
executed, unless it's stopped.
- Implement klogd wake up using irq work. This removes the ad-hoc
printk_tick()/printk_needs_cpu() hooks and make it working even in
dynticks mode.
- Cleanups and fixes."
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq: Export enable/disable_percpu_irq()
arch Kconfig: Remove references to IRQ_PER_CPU
irq_work: Remove return value from the irq_work_queue() function
genirq: Avoid deadlock in spurious handling
printk: Wake up klogd using irq_work
irq_work: Make self-IPIs optable
irq_work: Warn if there's still work on cpu_down
irq_work: Flush work on CPU_DYING
irq_work: Don't stop the tick with pending works
nohz: Add API to check tick state
irq_work: Remove CONFIG_HAVE_IRQ_WORK
irq_work: Fix racy check on work pending flag
irq_work: Fix racy IRQ_WORK_BUSY flag setting
Pull RCU changes from Ingo Molnar:
"SRCU changes:
- These include debugging aids, updates that move towards the goal of
permitting srcu_read_lock() and srcu_read_unlock() to be used from
idle and offline CPUs, and a few small fixes.
Changes to rcutorture and to RCU documentation:
- Posted to LKML at https://lkml.org/lkml/2013/1/26/188
Enhancements to uniprocessor handling in tiny RCU:
- Posted to LKML at https://lkml.org/lkml/2013/1/27/2
Tag RCU callbacks with grace-period number to simplify callback
advancement:
- Posted to LKML at https://lkml.org/lkml/2013/1/26/203
Miscellaneous fixes:
- Posted to LKML at https://lkml.org/lkml/2013/1/26/204"
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
srcu: use ACCESS_ONCE() to access sp->completed in srcu_read_lock()
srcu: Update synchronize_srcu_expedited()'s comments
srcu: Update synchronize_srcu()'s comments
srcu: Remove checks preventing idle CPUs from calling srcu_read_lock()
srcu: Remove checks preventing offline CPUs from calling srcu_read_lock()
srcu: Simple cleanup for cleanup_srcu_struct()
srcu: Add might_sleep() annotation to synchronize_srcu()
srcu: Simplify __srcu_read_unlock() via this_cpu_dec()
rcu: Allow rcutorture to be built at low optimization levels
rcu: Make rcutorture's shuffler task shuffle recently added tasks
rcu: Allow TREE_PREEMPT_RCU on UP systems
rcu: Provide RCU CPU stall warnings for tiny RCU
context_tracking: Add comments on interface and internals
rcu: Remove obsolete Kconfig option from comment
rcu: Remove unused code originally used for context tracking
rcu: Consolidate debugging Kconfig options
rcu: Correct 'optimized' to 'optimize' in header comment
rcu: Trace callback acceleration
rcu: Tag callback lists with corresponding grace-period number
rcutorture: Don't compare ptr with 0
...
commit d8e794dfd5 ("workqueue: set
delayed_work->timer function on initialization") exports function
delayed_work_timer_fn() only for GPL modules. This makes delayed-works
unusable for non-GPL modules, because initialization macro now requires
GPL symbol. For example schedule_delayed_work() available for non-GPL.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org # 3.7
seconds_overflow() is called from hard interrupt context even on
Preempt-RT. This requires the lock to be a raw_spinlock.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The get_timestamp() function is always called with current cpu,
thus using local_clock() would be more appropriate and it makes
the code shorter and cleaner IMHO.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Don Zickus <dzickus@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1356576585-28782-1-git-send-email-namhyung@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The reader side code has no requirement to disable interrupts while
sampling data. The sequence counter is enough to ensure consistency.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull in 'net' to take in the bug fixes that didn't make it into
3.8-final.
Also, deal with the semantic conflict of the change made to
net/ipv6/xfrm6_policy.c A missing rt6->n neighbour release
was added to 'net', but in 'net-next' we no longer cache the
neighbour entries in the ipv6 routes so that change is not
appropriate there.
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit: c1bf08ac "ftrace: Be first to run code modification on modules"
changed ftrace module notifier's priority to INT_MAX in order to
process the ftrace nops before anything else could touch them
(namely kprobes). This was the correct thing to do.
Unfortunately, the ftrace module notifier also contains the ftrace
clean up code. As opposed to the set up code, this code should be
run *after* all the module notifiers have run in case a module is doing
correct clean-up and unregisters its ftrace hooks. Basically, ftrace
needs to do clean up on module removal, as it needs to know about code
being removed so that it doesn't try to modify that code. But after it
removes the module from its records, if a ftrace user tries to remove
a probe, that removal will fail due as the record of that code segment
no longer exists.
Nothing really bad happens if the probe removal is called after ftrace
did the clean up, but the ftrace removal function will return an error.
Correct code (such as kprobes) will produce a WARN_ON() if it fails
to remove the probe. As people get annoyed by frivolous warnings, it's
best to do the ftrace clean up after everything else.
By splitting the ftrace_module_notifier into two notifiers, one that
does the module load setup that is run at high priority, and the other
that is called for module clean up that is run at low priority, the
problem is solved.
Cc: stable@vger.kernel.org
Reported-by: Frank Ch. Eigler <fche@redhat.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
If we pass fd of memory.usage_in_bytes of cgroup A to cgroup.event_control
of cgroup B, then we won't get memory usage notification from A but B!
What's worse, if A and B are in different mount hierarchy, we'll end up
accessing NULL pointer!
Disallow this kind of invalid usage.
Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Tejun Heo <tj@kernel.org>
commit 205a872bd6 ("cgroup: fix lockdep
warning for event_control") solved a deadlock by introducing a new
bug.
Move cgrp->event_list to a temporary list doesn't mean you can traverse
this list locklessly, because at the same time cgroup_event_wake() can
be called and remove the event from the list. The result of this race
is disastrous.
We adopt the way how kvm irqfd code implements race-free event removal,
which is now described in the comments in cgroup_event_wake().
v3:
- call eventfd_signal() no matter it's eventfd close or cgroup removal
that removes the cgroup event.
Acked-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
rename() will change dentry->d_name. The result of this race can
be worse than seeing partially rewritten name, but we might access
a stale pointer because rename() will re-allocate memory to hold
a longer name.
It's safe in the protection of dentry->d_lock.
v2: check NULL dentry before acquiring dentry lock.
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
In cgroup_exit() put_css_set_taskexit() is called without any lock,
which might lead to accessing a freed cgroup:
thread1 thread2
---------------------------------------------
exit()
cgroup_exit()
put_css_set_taskexit()
atomic_dec(cgrp->count);
rmdir();
/* not safe !! */
check_for_release(cgrp);
rcu_read_lock() can be used to make sure the cgroup is alive.
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
bc is the standard tool for multi-precision arithmetic. We switched
to Perl because akpm reported a hard-to-reproduce build hang, which
was very odd because affected and unaffected machines were all running
the same version of GNU bc.
Unfortunately switching to Perl required a really ugly "canning"
mechanism to support Perl < 5.8 installations lacking the Math::BigInt
module.
It was recently pointed out to me that some very old versions of GNU
make had problems with pipes in subshells, which was indeed the
construct used in the Makefile rules in that version of the patch;
Perl didn't need it so switching to Perl fixed the problem for
unrelated reasons. With the problem (hopefully) root-caused, we can
switch back to bc and do the arbitrary-precision arithmetic naturally.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
PARISC defines /proc/sys/kernel/unaligned-trap to runtime toggle
unaligned access emulation.
The exact mechanics of enablig/disabling are still arch specific, we can
make the sysctl usable by other arches.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
The only difference between wait_for_completion[_timeout]() and
wait_for_completion_io[_timeout]() is that the latter calls
io_schedule_timeout() instead of schedule_timeout() so that the caller
is accounted as waiting for IO, not just sleeping.
These functions can be used for correct iowait time accounting when the
completion struct is actually used for waiting for IO (e.g. completion
of a bio request in the block layer).
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The trinity fuzzer triggered a task_struct reference leak via
clock_nanosleep with CPU_TIMERs. do_cpu_nanosleep() calls
posic_cpu_timer_create(), but misses a corresponding
posix_cpu_timer_del() which leads to the task_struct reference leak.
Reported-and-tested-by: Tommi Rantala <tt.rantala@gmail.com>
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Dave Jones <davej@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20130215100810.GF4392@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Obviously this is a typo and could result in memory leaks if kzalloc
fails on a given cpu.
Signed-off-by: Daniel Baluta <dbaluta@ixiacom.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1360186160-7566-1-git-send-email-dbaluta@ixiacom.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Use the smpboot thread infrastructure. Mark the stopper thread
selfparking and park it after it has finished the take_cpu_down()
work.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Arjan van de Veen <arjan@infradead.org>
Cc: Paul Turner <pjt@google.com>
Cc: Richard Weinberger <rw@linutronix.de>
Cc: Magnus Damm <magnus.damm@gmail.com>
Link: http://lkml.kernel.org/r/20130131120741.686315164@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
To allow the stopper thread being managed by the smpboot thread
infrastructure separate out the task storage from the stopper data
structure.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Arjan van de Veen <arjan@infradead.org>
Cc: Paul Turner <pjt@google.com>
Cc: Richard Weinberger <rw@linutronix.de>
Cc: Magnus Damm <magnus.damm@gmail.com>
Link: http://lkml.kernel.org/r/20130131120741.626690384@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The stop machine threads are still killed when a cpu goes offline. The
reason is that the thread is used to bring the cpu down, so it can't
be parked along with the other per cpu threads.
Allow a per cpu thread to be excluded from automatic parking, so it
can park itself once it's done
Add a create callback function as well.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Arjan van de Veen <arjan@infradead.org>
Cc: Paul Turner <pjt@google.com>
Cc: Richard Weinberger <rw@linutronix.de>
Cc: Magnus Damm <magnus.damm@gmail.com>
Link: http://lkml.kernel.org/r/20130131120741.553993267@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
__ARCH_WANT_SYS_RT_SIGACTION,
__ARCH_WANT_SYS_RT_SIGSUSPEND,
__ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND,
__ARCH_WANT_COMPAT_SYS_SCHED_RR_GET_INTERVAL - not used anymore
CONFIG_GENERIC_{SIGALTSTACK,COMPAT_RT_SIG{ACTION,QUEUEINFO,PENDING,PROCMASK}} -
can be assumed always set.
workqueue has moved away from global_cwqs to worker_pools and with the
scheduled custom worker pools, wforkqueues will be associated with
pools which don't have anything to do with CPUs. The workqueue code
went through significant amount of changes recently and mass renaming
isn't likely to hurt much additionally. Let's replace 'cpu' with
'pool' so that it reflects the current design.
* s/struct cpu_workqueue_struct/struct pool_workqueue/
* s/cpu_wq/pool_wq/
* s/cwq/pwq/
This patch is purely cosmetic.
Signed-off-by: Tejun Heo <tj@kernel.org>
is_chained_work() was added before current_wq_worker() and implemented
its own ham-fisted way of finding out whether %current is a workqueue
worker - it iterates through all possible workers.
Drop the custom implementation and reimplement using
current_wq_worker().
Signed-off-by: Tejun Heo <tj@kernel.org>
c9e7cf273f ("workqueue: move busy_hash from global_cwq to
worker_pool") incorrectly converted is_chained_work() to use
get_gcwq() inside for_each_gcwq_cpu() while removing get_gcwq().
As cwq might not exist for all possible workqueue CPUs, @cwq can be
NULL and the following cwq deferences can lead to oops.
Fix it by using for_each_cwq_cpu() instead, which is the better one to
use anyway as we only need to check pools that the wq is associated
with.
Signed-off-by: Tejun Heo <tj@kernel.org>
The tracing of ia32 compat system calls has been a bit of a pain as they
use different system call numbers than the 64bit equivalents.
I wrote a simple 'lls' program that lists files. I compiled it as a i686
ELF binary and ran it under a x86_64 box. This is the result:
echo 0 > /debug/tracing/tracing_on
echo 1 > /debug/tracing/events/syscalls/enable
echo 1 > /debug/tracing/tracing_on ; ./lls ; echo 0 > /debug/tracing/tracing_on
grep lls /debug/tracing/trace
[.. skipping calls before TS_COMPAT is set ...]
lls-1127 [005] d... 936.409188: sys_recvfrom(fd: 0, ubuf: 4d560fc4, size: 0, flags: 8048034, addr: 8, addr_len: f7700420)
lls-1127 [005] d... 936.409190: sys_recvfrom -> 0x8a77000
lls-1127 [005] d... 936.409211: sys_lgetxattr(pathname: 0, name: 1000, value: 3, size: 22)
lls-1127 [005] d... 936.409215: sys_lgetxattr -> 0xf76ff000
lls-1127 [005] d... 936.409223: sys_dup2(oldfd: 4d55ae9b, newfd: 4)
lls-1127 [005] d... 936.409228: sys_dup2 -> 0xfffffffffffffffe
lls-1127 [005] d... 936.409236: sys_newfstat(fd: 4d55b085, statbuf: 80000)
lls-1127 [005] d... 936.409242: sys_newfstat -> 0x3
lls-1127 [005] d... 936.409243: sys_removexattr(pathname: 3, name: ffcd0060)
lls-1127 [005] d... 936.409244: sys_removexattr -> 0x0
lls-1127 [005] d... 936.409245: sys_lgetxattr(pathname: 0, name: 19614, value: 1, size: 2)
lls-1127 [005] d... 936.409248: sys_lgetxattr -> 0xf76e5000
lls-1127 [005] d... 936.409248: sys_newlstat(filename: 3, statbuf: 19614)
lls-1127 [005] d... 936.409249: sys_newlstat -> 0x0
lls-1127 [005] d... 936.409262: sys_newfstat(fd: f76fb588, statbuf: 80000)
lls-1127 [005] d... 936.409279: sys_newfstat -> 0x3
lls-1127 [005] d... 936.409279: sys_close(fd: 3)
lls-1127 [005] d... 936.421550: sys_close -> 0x200
lls-1127 [005] d... 936.421558: sys_removexattr(pathname: 3, name: ffcd00d0)
lls-1127 [005] d... 936.421560: sys_removexattr -> 0x0
lls-1127 [005] d... 936.421569: sys_lgetxattr(pathname: 4d564000, name: 1b1abc, value: 5, size: 802)
lls-1127 [005] d... 936.421574: sys_lgetxattr -> 0x4d564000
lls-1127 [005] d... 936.421575: sys_capget(header: 4d70f000, dataptr: 1000)
lls-1127 [005] d... 936.421580: sys_capget -> 0x0
lls-1127 [005] d... 936.421580: sys_lgetxattr(pathname: 4d710000, name: 3000, value: 3, size: 812)
lls-1127 [005] d... 936.421589: sys_lgetxattr -> 0x4d710000
lls-1127 [005] d... 936.426130: sys_lgetxattr(pathname: 4d713000, name: 2abc, value: 3, size: 32)
lls-1127 [005] d... 936.426141: sys_lgetxattr -> 0x4d713000
lls-1127 [005] d... 936.426145: sys_newlstat(filename: 3, statbuf: f76ff3f0)
lls-1127 [005] d... 936.426146: sys_newlstat -> 0x0
lls-1127 [005] d... 936.431748: sys_lgetxattr(pathname: 0, name: 1000, value: 3, size: 22)
Obviously I'm not calling newfstat with a fd of 4d55b085. The calls are
obviously incorrect, and confusing.
Other efforts have been made to fix this:
https://lkml.org/lkml/2012/3/26/367
But the real solution is to rewrite the syscall internals and come up
with a fixed solution. One that doesn't require all the kluge that the
current solution has.
Thus for now, instead of outputting incorrect data, simply ignore them.
With this patch the changes now have:
#> grep lls /debug/tracing/trace
#>
Compat system calls simply are not traced. If users need compat
syscalls, then they should just use the raw syscall tracepoints.
For an architecture to make their compat syscalls ignored, it must
define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS (done in asm/ftrace.h) and also
define an arch_trace_is_compat_syscall() function that will return true
if the current task should ignore tracing the syscall.
I want to stress that this change does not affect actual syscalls in any
way, shape or form. It is only used within the tracing system and
doesn't interfere with the syscall logic at all. The changes are
consolidated nicely into trace_syscalls.c and asm/ftrace.h.
I had to make one small modification to asm/thread_info.h and that was
to remove the include of asm/ftrace.h. As asm/ftrace.h required the
current_thread_info() it was causing include hell. That include was
added back in 2008 when the function graph tracer was added:
commit caf4b323 "tracing, x86: add low level support for ftrace return tracing"
It does not need to be included there.
Link: http://lkml.kernel.org/r/1360703939.21867.99.camel@gandalf.local.home
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
We're forgetting to reenable local interrupts on an error path.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Reported-by: Josh Boyer <jwboyer@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 12ad100046: "clockevents: Add generic timer broadcast function"
made tick_device_uses_broadcast set up the generic broadcast function
for dummy devices (where !tick_device_is_functional(dev)), but neglected
to set up the broadcast function for devices that stop in low power
states (with the CLOCK_EVT_FEAT_C3STOP flag).
When these devices enter low power states they will not have the generic
broadcast function assigned, and will bring down the system when an
attempt is made to broadcast to them.
This patch ensures that the broadcast function is also assigned for
devices which require broadcast in low power states.
Reported-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: nico@linaro.org
Cc: Marc.Zyngier@arm.com
Cc: Will.Deacon@arm.com
Cc: santosh.shilimkar@ti.com
Cc: john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
At present, the value of timeout for freezing is 20s, which is
meaningless in case that one thread is frozen with mutex locked
and another thread is trying to lock the mutex, as this time of
freezing will fail unavoidably.
And if there is no new wakeup event registered, the system will
waste at most 20s for such meaningless trying of freezing.
With this patch, the value of timeout can be configured to smaller
value, so such meaningless trying of freezing will be aborted in
earlier time, and later freezing can be also triggered in earlier
time. And more power will be saved.
In normal case on mobile phone, it costs real little time to freeze
processes. On some platform, it only costs about 20ms to freeze
user space processes and 10ms to freeze kernel freezable threads.
Signed-off-by: Liu Chuansheng <chuansheng.liu@intel.com>
Signed-off-by: Li Fei <fei.li@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM_SUSPEND_FREEZE state is a general state that
does not need any platform specific support, it equals
frozen processes + suspended devices + idle processors.
Compared with PM_SUSPEND_MEMORY,
PM_SUSPEND_FREEZE saves less power
because the system is still in a running state.
PM_SUSPEND_FREEZE has less resume latency because it does not
touch BIOS, and the processors are in idle state.
Compared with RTPM/idle,
PM_SUSPEND_FREEZE saves more power as
1. the processor has longer sleep time because processes are frozen.
The deeper c-state the processor supports, more power saving we can get.
2. PM_SUSPEND_FREEZE uses system suspend code path, thus we can get
more power saving from the devices that does not have good RTPM support.
This state is useful for
1) platforms that do not have STR, or have a broken STR.
2) platforms that have an extremely low power idle state,
which can be used to replace STR.
The following describes how PM_SUSPEND_FREEZE state works.
1. echo freeze > /sys/power/state
2. the processes are frozen.
3. all the devices are suspended.
4. all the processors are blocked by a wait queue
5. all the processors idles and enters (Deep) c-state.
6. an interrupt fires.
7. a processor is woken up and handles the irq.
8. if it is a general event,
a) the irq handler runs and quites.
b) goto step 4.
9. if it is a real wake event, say, power button pressing, keyboard touch, mouse moving,
a) the irq handler runs and activate the wakeup source
b) wakeup_source_activate() notifies the wait queue.
c) system starts resuming from PM_SUSPEND_FREEZE
10. all the devices are resumed.
11. all the processes are unfrozen.
12. system is back to working.
Known Issue:
The wakeup of this new PM_SUSPEND_FREEZE state may behave differently
from the previous suspend state.
Take ACPI platform for example, there are some GPEs that only enabled
when the system is in sleep state, to wake the system backk from S3/S4.
But we are not touching these GPEs during transition to PM_SUSPEND_FREEZE.
This means we may lose some wake event.
But on the other hand, as we do not disable all the Interrupts during
PM_SUSPEND_FREEZE, we may get some extra "wakeup" Interrupts, that are
not available for S3/S4.
The patches has been tested on an old Sony laptop, and here are the results:
Average Power:
1. RPTM/idle for half an hour:
14.8W, 12.6W, 14.1W, 12.5W, 14.4W, 13.2W, 12.9W
2. Freeze for half an hour:
11W, 10.4W, 9.4W, 11.3W 10.5W
3. RTPM/idle for three hours:
11.6W
4. Freeze for three hours:
10W
5. Suspend to Memory:
0.5~0.9W
Average Resume Latency:
1. RTPM/idle with a black screen: (From pressing keyboard to screen back)
Less than 0.2s
2. Freeze: (From pressing power button to screen back)
2.50s
3. Suspend to Memory: (From pressing power button to screen back)
4.33s
>From the results, we can see that all the platforms should benefit from
this patch, even if it does not have Low Power S0.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
wait_for_kprobe_optimizer() seems largely broken. It uses
optimizer_comp which is never re-initialized, so
wait_for_kprobe_optimizer() will never wait for anything once
kprobe_optimizer() finishes all pending jobs for the first time.
Also, aside from completion, delayed_work_pending() is %false once
kprobe_optimizer() starts execution and wait_for_kprobe_optimizer()
won't wait for it.
Reimplement it so that it flushes optimizing_work until
[un]optimizing_lists are empty. Note that this also makes
optimizing_work execute immediately if someone's waiting for it, which
is the nicer behavior.
Only compile tested.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
At init time, if the system time is "warped" forward in warp_clock()
it will differ from the hardware clock by sys_tz.tz_minuteswest. This time
difference is not taken into account when ntp updates the hardware clock,
and this causes the system time to jump forward by this offset every reboot.
The kernel must take this offset into account when writing the system time
to the hardware clock in the ntp code. This patch adds
persistent_clock_is_local which indicates that an offset has been applied
in warp_clock() and accounts for the "warp" before writing the hardware
clock.
x86 does not have this problem as rtc writes are software limited to a
+/-15 minute window relative to the current rtc time. Other arches, such
as powerpc, however do a full synchronization of the system time to the
rtc and will see this problem.
[v2]: generated against tip/timers/core
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Synchronize with 'net' in order to sort out some l2tp, wireless, and
ipv6 GRE fixes that will be built on top of in 'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>
uprobe_perf_open/close call the costly uprobe_apply() every time,
we can avoid it if:
- "nr_systemwide != 0" is not changed.
- There is another process/thread with the same ->mm.
- copy_proccess() does inherit_event(). dup_mmap() preserves the
inserted breakpoints.
- event->attr.enable_on_exec == T, we can rely on uprobe_mmap()
called by exec/mmap paths.
- tp_target is exiting. Only _close() checks PF_EXITING, I don't
think TRACE_REG_PERF_OPEN can hit the dying task too often.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Change uprobe_trace_func() and uprobe_perf_func() to return "int". Change
uprobe_dispatcher() to return "trace_ret | perf_ret" although this is not
needed, currently TP_FLAG_TRACE/TP_FLAG_PROFILE are mutually exclusive.
The only functional change is that uprobe_perf_func() checks the filtering
too and returns UPROBE_HANDLER_REMOVE if nobody wants to trace current.
Testing:
# perf probe -x /lib/libc.so.6 syscall
# perf record -e probe_libc:syscall -i perl -e 'fork; syscall -1 for 1..10; wait'
# perf report --show-total-period
100.00% 10 perl libc-2.8.so [.] syscall
Before this patch:
# cat /sys/kernel/debug/tracing/uprobe_profile
/lib/libc.so.6 syscall 20
A child process doesn't have a counter, but still it hits this breakoint
"copied" by dup_mmap().
After the patch:
# cat /sys/kernel/debug/tracing/uprobe_profile
/lib/libc.so.6 syscall 11
The child process hits this int3 only once and does unapply_uprobe().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Finally implement uprobe_perf_filter() which checks ->nr_systemwide or
->perf_events to figure out whether we need to insert the breakpoint.
uprobe_perf_open/close are changed to do uprobe_apply(true/false) when
the new perf event comes or goes away.
Note that currently this is very suboptimal:
- uprobe_register() called by TRACE_REG_PERF_REGISTER becomes a
heavy nop, consumer->filter() always returns F at this stage.
As it was already discussed we need uprobe_register_only() to
avoid the costly register_for_each_vma() when possible.
- uprobe_apply() is oftenly overkill. Unless "nr_systemwide != 0"
changes we need uprobe_apply_mm(), unapply_uprobe() is almost
what we need.
- uprobe_apply() can be simply avoided sometimes, see the next
changes.
Testing:
# perf probe -x /lib/libc.so.6 syscall
# perl -e 'syscall -1 while 1' &
[1] 530
# perf record -e probe_libc:syscall perl -e 'syscall -1 for 1..10; sleep 1'
# perf report --show-total-period
100.00% 10 perl libc-2.8.so [.] syscall
Before this patch:
# cat /sys/kernel/debug/tracing/uprobe_profile
/lib/libc.so.6 syscall 79291
A huge ->nrhit == 79291 reflects the fact that the background process
530 constantly hits this breakpoint too, even if doesn't contribute to
the output.
After the patch:
# cat /sys/kernel/debug/tracing/uprobe_profile
/lib/libc.so.6 syscall 10
This shows that only the target process was punished by int3.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Introduce "struct trace_uprobe_filter" which records the "active"
perf_event's attached to ftrace_event_call. For the start we simply
use list_head, we can optimize this later if needed. For example, we
do not really need to record an event with ->parent != NULL, we can
rely on parent->child_list. And we can certainly do some optimizations
for the case when 2 events have the same ->tp_target or tp_target->mm.
Change trace_uprobe_register() to process TRACE_REG_PERF_OPEN/CLOSE
and add/del this perf_event to the list.
We can probably avoid any locking, but lets start with the "obvioulsy
correct" trace_uprobe_filter->rwlock which protects everything.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Currently it is not possible to change the filtering constraints after
uprobe_register(), so a consumer can not, say, start to trace a task/mm
which was previously filtered out, or remove the no longer needed bp's.
Introduce uprobe_apply() which simply does register_for_each_vma() again
to consult uprobe_consumer->filter() and install/remove the breakpoints.
The only complication is that register_for_each_vma() can no longer
assume that uprobe->consumers should be consulter if is_register == T,
so we change it to accept "struct uprobe_consumer *new" instead.
Unlike uprobe_register(), uprobe_apply(true) doesn't do "unregister" if
register_for_each_vma() fails, it is up to caller to handle the error.
Note: we probably need to cleanup the current interface, it is strange
that uprobe_apply/unregister need inode/offset. We should either change
uprobe_register() to return "struct uprobe *", or add a private ->uprobe
member in uprobe_consumer. And in the long term uprobe_apply() should
take a single argument, uprobe or consumer, even "bool add" should go
away.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
sys_perf_event_open()->perf_init_event(event) is called before
find_get_context(event), this means that event->ctx == NULL when
class->reg(TRACE_REG_PERF_REGISTER/OPEN) is called and thus it
can't know if this event is per-task or system-wide.
This patch adds hw_perf_event->tp_target for PERF_TYPE_TRACEPOINT,
this is analogous to PERF_TYPE_BREAKPOINT/bp_target we already have.
The patch also moves ->bp_target up so that it can overlap with the
new member, this can help the compiler to generate the better code.
trace_uprobe_register() will use it for prefiltering to avoid the
unnecessary breakpoints in mm's we do not want to trace.
->tp_target doesn't have its own reference, but we can rely on the
fact that either sys_perf_event_open() holds a reference, or it is
equal to event->ctx->task. So this pointer is always valid until
free_event().
Also add the "struct list_head tp_list" into this union. It is not
strictly necessary, but it can simplify the next changes and we can
add it for free.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Move tu->nhit++ from uprobe_trace_func() to uprobe_dispatcher().
->nhit counts how many time we hit the breakpoint inserted by this
uprobe, we do not want to loose this info if uprobe was enabled by
sys_perf_event_open().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
trace_uprobe->consumer and "struct uprobe_trace_consumer" add the
unnecessary indirection and complicate the code for no reason.
This patch simply embeds uprobe_consumer into "struct trace_uprobe",
all other changes only fix the compilation errors.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
probe_event_enable/disable() check tu->consumer != NULL to avoid the
wrong uprobe_register/unregister().
We are going to kill this pointer and "struct uprobe_trace_consumer",
so we add the new helper, is_trace_uprobe_enabled(), which can rely
on TP_FLAG_TRACE/TP_FLAG_PROFILE instead.
Note: the current logic doesn't look optimal, it is not clear why
TP_FLAG_TRACE/TP_FLAG_PROFILE are mutually exclusive, we will probably
change this later.
Also kill the unused TP_FLAG_UPROBE.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
probe_event_enable/disable() check tu->inode != NULL at the start.
This is ugly, if igrab() can fail create_trace_uprobe() should not
succeed and "postpone" the failure.
And S_ISREG(inode->i_mode) check added by d24d7dbf is not safe.
Note: alloc_uprobe() should probably check igrab() != NULL as well.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
probe_event_enable() does uprobe_register() and only after that sets
utc->tu and tu->consumer/flags. This can race with uprobe_dispatcher()
which can miss these assignments or see them out of order. Nothing
really bad can happen, but this doesn't look clean/safe.
And this does not allow to use uprobe_consumer->filter() we are going
to add, it is called by uprobe_register() and it needs utc->tu.
Change this code to initialize everything before uprobe_register(), and
reset tu->consumer/flags if it fails. We can't race with event_disable(),
the caller holds event_mutex, and if we could the code would be wrong
anyway.
In fact I think uprobe_trace_consumer should die, it buys nothing but
complicates the code. We can simply add uprobe_consumer into trace_uprobe.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
create_trace_uprobe() does kern_path() to find ->d_inode, but forgets
to do path_put(). We can do this right after igrab().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
The original pull message for uprobes (commit 654443e2) noted:
This tree includes uprobes support in 'perf probe' - but SystemTap
(and other tools) can take advantage of user probe points as well.
In order to actually be usable in module-based tools like SystemTap, the
interface needs to be exported. This patch first adds the obvious
exports for uprobe_register and uprobe_unregister. Then it also adds
one for task_user_regset_view, which is necessary to get the correct
state of userspace registers.
Signed-off-by: Josh Stone <jistone@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
utask->xol_vaddr is either zero or valid, remove the bogus
IS_ERR_VALUE() check in xol_free_insn_slot().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Anton Arapov <anton@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
handle_swbp() does get_utask() before can_skip_sstep() for no reason,
we do not need ->utask if can_skip_sstep() succeeds.
Move get_utask() to pre_ssout() who actually starts to use it. Move
the initialization of utask->active_uprobe/state as well. This way
the whole initialization is consolidated in pre_ssout().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Anton Arapov <anton@redhat.com>
pre_ssout() should do xol_free_insn_slot() if arch_uprobe_pre_xol()
fails, otherwise nobody will free the allocated slot.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Anton Arapov <anton@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
pre_ssout()->xol_get_insn_slot() path is confusing and buggy. This patch
cleanups the code, the next one fixes the bug.
Change xol_get_insn_slot() to only allocate the slot and do nothing more,
move the initialization of utask->xol_vaddr/vaddr into pre_ssout().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Anton Arapov <anton@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Rename add_utask() into get_utask() and change it to allocate on
demand to simplify the caller. Like get_xol_area() it will have
more users.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Anton Arapov <anton@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Currently only xol_get_insn_slot() does get_xol_area() + xol_alloc_area(),
but this will have more users and we do not want to copy-and-paste this
code. This patch simply moves xol_alloc_area() into get_xol_area() to
simplify the current and future code.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Anton Arapov <anton@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Move alloc_page() from xol_add_vma() to xol_alloc_area() to cleanup
the code. This separates the memory allocations and consolidates the
-EALREADY cleanups and the error handling.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Anton Arapov <anton@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Change handle_swbp() to set regs->ip = bp_vaddr in advance, this is
what consumer->handler() needs but uprobe_get_swbp_addr() is not
exported.
This also simplifies the code and makes it more consistent across
the supported architectures. handle_swbp() becomes the only caller
of uprobe_get_swbp_addr().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Currrently the are 2 problems with pre-filtering:
1. It is not possible to add/remove a task (mm) after uprobe_register()
2. A forked child inherits all breakpoints and uprobe_consumer can not
control this.
This patch does the first step to improve the filtering. handler_chain()
removes the breakpoints installed by this uprobe from current->mm if all
handlers return UPROBE_HANDLER_REMOVE.
Note that handler_chain() relies on ->register_rwsem to avoid the race
with uprobe_register/unregister which can add/del a consumer, or even
remove and then insert the new uprobe at the same address.
Perhaps we will add uprobe_apply_mm(uprobe, mm, is_register) and teach
copy_mm() to do filter(UPROBE_FILTER_FORK), but I think this change makes
sense anyway.
Note: instead of checking the retcode from uc->handler, we could add
uc->filter(UPROBE_FILTER_BPHIT). But I think this is not optimal to
call 2 hooks in a row. This buys nothing, and if handler/filter do
something nontrivial they will probably do the same work twice.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Finally add uprobe_consumer->filter() and change consumer_filter()
to actually call this method.
Note that ->filter() accepts mm_struct, not task_struct. Because:
1. We do not have for_each_mm_user(mm, task).
2. Even if we implement for_each_mm_user(), ->filter() can
use it itself.
3. It is not clear who will actually need this interface to
do the "nontrivial" filtering.
Another argument is "enum uprobe_filter_ctx", consumer->filter() can
use it to figure out why/where it was called. For example, perhaps
we can add UPROBE_FILTER_PRE_REGISTER used by build_map_info() to
quickly "nack" the unwanted mm's. In this case consumer should know
that it is called under ->i_mmap_mutex.
See the previous discussion at http://marc.info/?t=135214229700002
Perhaps we should pass more arguments, vma/vaddr?
Note: this patch obviously can't help to filter out the child created
by fork(), this will be addressed later.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
filter_chain() was added into install_breakpoint/remove_breakpoint to
simplify the initial changes but this is sub-optimal.
This patch shifts the callsite to the callers, register_for_each_vma()
and uprobe_mmap(). This way:
- It will be easier to add the new arguments. This is the main reason,
we can do more optimizations later.
- register_for_each_vma(is_register => true) can be optimized, we only
need to consult the new consumer. The previous consumers were already
asked when they called uprobe_register().
This patch also moves the MMF_HAS_UPROBES check from remove_breakpoint(),
this allows to avoid the potentionally costly filter_chain(). Note that
register_for_each_vma(is_register => false) doesn't really need to take
->consumer_rwsem, but I don't think it makes sense to optimize this and
introduce filter_chain_lockless().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
uprobe_register() and uprobe_unregister() are the only users of
mutex_lock(uprobes_hash(inode)), and the only reason why we can't
simply remove it is that we need to ensure that delete_uprobe() is
not possible after alloc_uprobe() and before consumer_add().
IOW, we need to ensure that when we take uprobe->register_rwsem
this uprobe is still valid and we didn't race with _unregister()
which called delete_uprobe() in between.
With this patch uprobe_register() simply checks uprobe_is_active()
and retries if it hits this very unlikely race. uprobes_mutex[] is
no longer needed and can be removed.
There is another reason for this change, prepare_uprobe() should be
folded into alloc_uprobe() and we do not want to hold the extra locks
around read_mapping_page/etc.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Anton Arapov <anton@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
The lifetime of uprobe->rb_node and uprobe->inode is not refcounted,
delete_uprobe() is called when we detect that uprobe has no consumers,
and it would be deadly wrong to do this twice.
Change delete_uprobe() to WARN() if it was already called. We use
RB_CLEAR_NODE() to mark uprobe "inactive", then RB_EMPTY_NODE() can
be used to detect this case.
RB_EMPTY_NODE() is not used directly, we add the trivial helper for
the next change.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Anton Arapov <anton@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
uprobe_events counts the number of uprobes in uprobes_tree but
it is used as a boolean. We can use RB_EMPTY_ROOT() instead.
Probably no_uprobe_events() added by this patch can have more
callers, say, mmf_recalc_uprobes().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Anton Arapov <anton@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Now that ->register_rwsem is safe under ->mmap_sem we can kill
->copy_mutex and abuse down_write(&uprobe->consumer_rwsem).
This makes prepare_uprobe() even more ugly, but we should kill
it anyway.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Simply remove UPROBE_RUN_HANDLER and the corresponding code.
It can only help if uprobe has a single consumer, and in fact
it is no longer needed after handler_chain() was changed to use
->register_rwsem, we simply can not race with uprobe_register().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Now that it safe to use ->consumer_rwsem under ->mmap_sem we can
almost finish the implementation of filter_chain(). It still lacks
the actual uc->filter(...) call but othewrwise it is ready, just
it pretends that ->filter() always returns true.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Introduce uprobe->register_rwsem. It is taken for writing around
__uprobe_register/unregister.
Change handler_chain() to use this sem rather than consumer_rwsem.
The main reason for this change is that we have the nasty problem
with mmap_sem/consumer_rwsem dependency. filter_chain() needs to
protect uprobe->consumers like handler_chain(), but they can not
use the same lock. filter_chain() can be called under ->mmap_sem
(currently this is always true), but we want to allow ->handler()
to play with the probed task's memory, and this needs ->mmap_sem.
Alternatively we could use srcu, but synchronize_srcu() is very
slow and ->register_rwsem allows us to do more. In particular, we
can teach handler_chain() to do remove_breakpoint() if this bp is
"nacked" by all consumers, we know that we can't race with the
new consumer which does uprobe_register().
See also the next patches. uprobes_mutex[] is almost ready to die.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
To support the filtering uprobe_register() should do
register_for_each_vma(true) every time the new consumer comes,
we need to install the previously nacked breakpoints.
Note:
- uprobes_mutex[] should die, what it actually protects is
alloc_uprobe().
- UPROBE_RUN_HANDLER should die too, obviously it can't work
unless uprobe has a single consumer. The consumer should
serialize with _register/_unregister itself. Or this flag
should live in uprobe_consumer->state.
- Perhaps we can do some optimizations later. For example, if
filter_chain() never returns false uprobe can record this
fact and avoid the unnecessary register_for_each_vma().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
uprobe_unregister() removes the breakpoints only if the last consumer
goes away. To support the filtering it should do this every time, we
want to remove the breakpoints which nobody else want to keep.
Note: given that filter_chain() is not actually implemented, this patch
itself doesn't change the behaviour yet, register_for_each_vma(false)
is a heavy "nop" unless there are no more consumers.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Add the new helper filter_chain(). Currently it is only placeholder,
the comment explains what is should do. We will change it later to
consult every consumer to decide whether we need to install the swbp.
Until then it works as if any consumer returns true, this matches the
current behavior.
Change install_breakpoint() to call filter_chain() instead of checking
uprobe->consumers != NULL. We obviously need this, and this equally
closes the race with _unregister().
Change remove_breakpoint() to call this helper too. Currently this is
pointless because remove_breakpoint() is only called when the last
consumer goes away, but we will change this.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
uprobe_consumer->filter() is pointless in its current form, kill it.
We will add it back, but with the different signature/semantics. Perhaps
we will even re-introduce the callsite in handler_chain(), but not to
just skip uc->handler().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
register/unregister verifies that inode/uc != NULL. For what?
This really looks like "hide the potential problem", the caller
should pass the valid data.
register() also checks uc->next == NULL, probably to prevent the
double-register but the caller can do other stupid/wrong things.
If we do this check, then we should document that uc->next should
be cleared before register() and add BUG_ON().
Also add the small comment about the i_size_read() check.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cosmetic. __set_bit(UPROBE_SKIP_SSTEP) is the part of initialization,
it is not clear why it is set in insert_uprobe().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
This reverts commit ff0d05bf73.
Now that we have all the locking fixes in place, we can revert the
revert. This re-enables lockdep tracking for the console lock,
daee779718.
Signed-off-by: Dave Airlie <airlied@redhat.com>
defined(@array) is deprecated in Perl and gives off a warning.
Restructure the code to remove that warning.
[ hpa: it would be interesting to revert to the timeconst.bc script.
It appears that the failures reported by akpm during testing of
that script was due to a known broken version of make, not a problem
with bc. The Makefile rules could probably be restructured to avoid
the make bug, or it is probably old enough that it doesn't matter. ]
Reported-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@vger.kernel.org>
The old SRCU implementation loads sp->completed within an
RCU-sched section, courtesy of preempt_disable(). This was required
due to the use of synchronize_sched() in the old implemenation's
synchronize_srcu(). However, the new implementation does not rely
on synchronize_sched(), so it in turn does not require the load of
sp->completed and the ->c[] counter to be in a single preempt-disabled
region of code. This commit therefore moves the sp->completed access
outside of the preempt-disabled region and applies ACCESS_ONCE().
The resulting code is almost as the same as before, but it removes the
now-misleading rcu_dereference_index_check() call.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Because synchronize_srcu_expedited() no longer uses
synchronize_rcu_sched_expedited(), synchronize_srcu_expedited() no longer
indirectly acquires any CPU-hotplug-related locks. This commit therefore
updates the comments accordingly.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The core of SRCU is changed, but synchronize_srcu()'s comments describe
the old algorithm. This commit therefore updates them to match the
new algorithm.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Pack six lines of code into two lines.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Although synchronize_srcu() can sleep, it will not sleep if the fast
path succeeds, which means that illegal use of synchronize_rcu()
might go unnoticed. This commit therefore adds might_sleep(), which
unconditionally catches illegal use of synchronize_rcu() from atomic
context.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit replaces disabling of preemption and decrement of a per-CPU
variable with this_cpu_dec(), which avoids preemption disabling on x86
and shortens the code on all platforms.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Currently, __queue_work() chooses the pool to queue a work item to and
then determines cwq from the target wq and the chosen pool. This is a
bit backwards in that we can determine cwq first and simply use
cwq->pool. This way, we can skip get_std_worker_pool() in queueing
path which will be a hurdle when implementing custom worker pools.
Update __queue_work() such that it chooses the target cwq and then use
cwq->pool instead of the other way around. While at it, add missing
{} in an if statement.
This patch doesn't introduce any functional changes.
tj: The original patch had two get_cwq() calls - the first to
determine the pool by doing get_cwq(cpu, wq)->pool and the second
to determine the matching cwq from get_cwq(pool->cpu, wq).
Updated the function such that it chooses cwq instead of pool and
removed the second call. Rewrote the description.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
get_work_pool_id() currently first obtains pool using get_work_pool()
and then return pool->id. For an off-queue work item, this involves
obtaining pool ID from worker->data, performing idr_find() to find the
matching pool and then returning its pool->id which of course is the
same as the one which went into idr_find().
Just open code WORK_STRUCT_CWQ case and directly return pool ID from
work->data.
tj: The original patch dropped on-queue work item handling and renamed
the function to offq_work_pool_id(). There isn't much benefit in
doing so. Handling it only requires a single if() and we need at
least BUG_ON(), which is also a branch, even if we drop on-queue
handling. Open code WORK_STRUCT_CWQ case and keep the function in
line with get_work_pool(). Rewrote the description.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
As nr_running is likely to be accessed from other CPUs during
try_to_wake_up(), it was kept outside worker_pool; however, while less
frequent, other fields in worker_pool are accessed from other CPUs
for, e.g., non-reentrancy check. Also, with recent pool related
changes, accessing nr_running matching the worker_pool isn't as simple
as it used to be.
Move nr_running inside worker_pool. Keep it aligned to cacheline and
define CPU pools using DEFINE_PER_CPU_SHARED_ALIGNED(). This should
give at least the same cacheline behavior.
get_pool_nr_running() is replaced with direct pool->nr_running
accesses.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Joonsoo Kim <js1304@gmail.com>
Move rt scheduler definitions out of include/linux/sched.h into
new file include/linux/sched/rt.h
Signed-off-by: Clark Williams <williams@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20130207094707.7b9f825f@riff.lan
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add a /proc/sys/kernel scheduler knob named
sched_rr_timeslice_ms that allows global changing of the
SCHED_RR timeslice value. User visable value is in milliseconds
but is stored as jiffies. Setting to 0 (zero) resets to the
default (currently 100ms).
Signed-off-by: Clark Williams <williams@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20130207094704.13751796@riff.lan
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Move the sysctl-related bits from include/linux/sched.h into
a new file: include/linux/sched/sysctl.h. Then update source
files requiring access to those bits by including the new
header file.
Signed-off-by: Clark Williams <williams@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20130207094659.06dced96@riff.lan
Signed-off-by: Ingo Molnar <mingo@kernel.org>
With the recent is-work-queued-here test simplification, the nested
if() in try_to_grab_pending() can be collapsed. Collapse it.
This patch is purely cosmetic.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Currently, determining whether a work item is queued on a locked pool
involves somewhat convoluted memory barrier dancing. It goes like the
following.
* When a work item is queued on a pool, work->data is updated before
work->entry is linked to the pending list with a wmb() inbetween.
* When trying to determine whether a work item is currently queued on
a pool pointed to by work->data, it locks the pool and looks at
work->entry. If work->entry is linked, we then do rmb() and then
check whether work->data points to the current pool.
This works because, work->data can only point to a pool if it
currently is or were on the pool and,
* If it currently is on the pool, the tests would obviously succeed.
* It it left the pool, its work->entry was cleared under pool->lock,
so if we're seeing non-empty work->entry, it has to be from the work
item being linked on another pool. Because work->data is updated
before work->entry is linked with wmb() inbetween, work->data update
from another pool is guaranteed to be visible if we do rmb() after
seeing non-empty work->entry. So, we either see empty work->entry
or we see updated work->data pointin to another pool.
While this works, it's convoluted, to put it mildly. With recent
updates, it's now guaranteed that work->data points to cwq only while
the work item is queued and that updating work->data to point to cwq
or back to pool is done under pool->lock, so we can simply test
whether work->data points to cwq which is associated with the
currently locked pool instead of the convoluted memory barrier
dancing.
This patch replaces the memory barrier based "are you still here,
really?" test with much simpler "does work->data points to me?" test -
if work->data points to a cwq which is associated with the currently
locked pool, the work item is guaranteed to be queued on the pool as
work->data can start and stop pointing to such cwq only under
pool->lock and the start and stop coincide with queue and dequeue.
tj: Rewrote the comments and description.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
We plan to use work->data pointing to cwq as the synchronization
invariant when determining whether a given work item is on a locked
pool or not, which requires work->data pointing to cwq only while the
work item is queued on the associated pool.
With delayed_work updated not to overload work->data for target
workqueue recording, the only case where we still have off-queue
work->data pointing to cwq is try_to_grab_pending() which doesn't
update work->data after stealing a queued work item. There's no
reason for try_to_grab_pending() to not update work->data to point to
the pool instead of cwq, like the normal execution does.
This patch adds set_work_pool_and_keep_pending() which makes
work->data point to pool instead of cwq but keeps the pending bit
unlike set_work_pool_and_clear_pending() (surprise!).
After this patch, it's guaranteed that only queued work items point to
cwqs.
This patch doesn't introduce any visible behavior change.
tj: Renamed the new helper function to match
set_work_pool_and_clear_pending() and rewrote the description.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
To avoid executing the same work item from multiple CPUs concurrently,
a work_struct records the last pool it was on in its ->data so that,
on the next queueing, the pool can be queried to determine whether the
work item is still executing or not.
A delayed_work goes through timer before actually being queued on the
target workqueue and the timer needs to know the target workqueue and
CPU. This is currently achieved by modifying delayed_work->work.data
such that it points to the cwq which points to the target workqueue
and the last CPU the work item was on. __queue_delayed_work()
extracts the last CPU from delayed_work->work.data and then combines
it with the target workqueue to create new work.data.
The only thing this rather ugly hack achieves is encoding the target
workqueue into delayed_work->work.data without using a separate field,
which could be a trade off one can make; unfortunately, this entangles
work->data management between regular workqueue and delayed_work code
by setting cwq pointer before the work item is actually queued and
becomes a hindrance for further improvements of work->data handling.
This can be easily made sane by adding a target workqueue field to
delayed_work. While delayed_work is used widely in the kernel and
this does make it a bit larger (<5%), I think this is the right
trade-off especially given the prospect of much saner handling of
work->data which currently involves quite tricky memory barrier
dancing, and don't expect to see any measureable effect.
Add delayed_work->wq and drop the delayed_work->work.data overloading.
tj: Rewrote the description.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Currently, work_busy() first tests whether the work has a pool
associated with it and if not, considers it idle. This works fine
even for delayed_work.work queued on timer, as __queue_delayed_work()
sets cwq on delayed_work.work - a queued delayed_work always has its
cwq and thus pool associated with it.
However, we're about to update delayed_work queueing and this won't
hold. Update work_busy() such that it tests WORK_STRUCT_PENDING
before the associated pool. This doesn't make any noticeable behavior
difference now.
With work_pending() test moved, the function read a lot better with
"if (!pool)" test flipped to positive. Flip it.
While at it, lose the comment about now non-existent reentrant
workqueues.
tj: Reorganized the function and rewrote the description.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Now that workqueue has moved away from gcwqs, workqueue no longer has
the need to have a CPU identifier indicating "no cpu associated" - we
now use WORK_OFFQ_POOL_NONE instead - and most uses of WORK_CPU_NONE
are gone.
The only left usage is as the end marker for for_each_*wq*()
iterators, where the name WORK_CPU_NONE is confusing w/o actual
WORK_CPU_NONE usages. Similarly, WORK_CPU_LAST which equals
WORK_CPU_NONE no longer makes sense.
Replace both WORK_CPU_NONE and LAST with WORK_CPU_END. This patch
doesn't introduce any functional difference.
tj: s/WORK_CPU_LAST/WORK_CPU_END/ and rewrote the description.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
All in-kernel users of class_find_device() don't really need mutable
data for match callback.
In two places (kernel/power/suspend_test.c, drivers/scsi/osd/osd_uld.c)
this patch changes match callbacks to use const search data.
The const is propagated to rtc_class_open() and power_supply_get_by_name()
parameters.
Note that there's a dev reference leak in suspend_test.c that's not
touched in this patch.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
TCP Appropriate Byte Count was added by me, but later disabled.
There is no point in maintaining it since it is a potential source
of bugs and Linux already implements other better window protection
heuristics.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Typical cputime stats infrastructure relies on the timer tick and
its periodic polling on the CPU to account the amount of time
spent by the CPUs and the tasks per high level domains such as
userspace, kernelspace, guest, ...
Now we are preparing to implement full dynticks capability on
Linux for Real Time and HPC users who want full CPU isolation.
This feature requires a cputime accounting that doesn't depend
on the timer tick.
To implement it, this new cputime infrastructure plugs into
kernel/user/guest boundaries to take snapshots of cputime and
flush these to the stats when needed. This performs pretty
much like CONFIG_VIRT_CPU_ACCOUNTING except that context location
and cputime snaphots are synchronized between write and read
side such that the latter can safely retrieve the pending tickless
cputime of a task and add it to its latest cputime snapshot to
return the correct result to the user.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
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Merge tag 'full-dynticks-cputime-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into sched/core
Pull full-dynticks (user-space execution is undisturbed and
receives no timer IRQs) preparation changes that convert the
cputime accounting code to be full-dynticks ready,
from Frederic Weisbecker:
"This implements the cputime accounting on full dynticks CPUs.
Typical cputime stats infrastructure relies on the timer tick and
its periodic polling on the CPU to account the amount of time
spent by the CPUs and the tasks per high level domains such as
userspace, kernelspace, guest, ...
Now we are preparing to implement full dynticks capability on
Linux for Real Time and HPC users who want full CPU isolation.
This feature requires a cputime accounting that doesn't depend
on the timer tick.
To implement it, this new cputime infrastructure plugs into
kernel/user/guest boundaries to take snapshots of cputime and
flush these to the stats when needed. This performs pretty
much like CONFIG_VIRT_CPU_ACCOUNTING except that context location
and cputime snaphots are synchronized between write and read
side such that the latter can safely retrieve the pending tickless
cputime of a task and add it to its latest cputime snapshot to
return the correct result to the user."
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In 7b270f6099 "sched: Bail out of yield_to when source and
target runqueue has one task" we changed this to store -ESRCH so
it needs to be signed.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: kbuild@01.org
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mike Galbraith <efault@gmx.de>
Link: http://lkml.kernel.org/r/20130205113751.GA20521@elgon.mountain
Signed-off-by: Ingo Molnar <mingo@kernel.org>
hrtimer_enqueue_reprogram contains a race which could result in
timer.base switch during unlock/lock sequence.
hrtimer_enqueue_reprogram is releasing the lock protecting the timer
base for calling raise_softirq_irqsoff() due to a lock ordering issue
versus rq->lock.
If during that time another CPU calls __hrtimer_start_range_ns() on
the same hrtimer, the timer base might switch, before the current CPU
can lock base->lock again and therefor the unlock_timer_base() call
will unlock the wrong lock.
[ tglx: Added comment and massaged changelog ]
Signed-off-by: Leonid Shatz <leonid.shatz@ravellosystems.com>
Signed-off-by: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1359981217-389-1-git-send-email-izik.eidus@ravellosystems.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Conflicts:
kernel/irq_work.c
Add support for printk in full dynticks CPU.
* Don't stop tick with irq works pending. This
fix is generally useful and concerns archs that
can't raise self IPIs.
* Flush irq works before CPU offlining.
* Introduce "lazy" irq works that can wait for the
next tick to be executed, unless it's stopped.
* Implement klogd wake up using irq work. This
removes the ad-hoc printk_tick()/printk_needs_cpu()
hooks and make it working even in dynticks mode.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
There's no reason kgdb.h itself needs to include the 8250 serial port
header file. So push it down to the _very_ limited number of individual
drivers that need the values in that file, and fix up the places where
people really wanted serial_core.h and platform_device.h.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull scheduler fixes from Ingo Molnar:
"Three small fixlets"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/debug: Fix format string for 32-bit platforms
sched: Fix warning in kernel/sched/fair.c
sched/rt: Use root_domain of rt_rq not current processor
Pull perf fixes from Ingo Molnar:
"Three fixlets and two small (and low risk) hw-enablement changes"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Fix event group context move
x86/perf: Add IvyBridge EP support
perf/x86: Fix P6 driver section warning
arch/x86/tools/insn_sanity.c: Identify source of messages
perf/x86: Enable Intel Lincroft/Penwell/Cloverview Atom support
Pull two small RCU fixlets from Ingo Molnar.
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
rcu: Make rcu_nocb_poll an early_param instead of module_param
rcu: Prevent soft-lockup complaints about no-CBs CPUs
The uses of trace_clock_local() are dead code when CONFIG_RCU_TRACE=n,
but some compilers might nevertheless generate code calling this function.
This commit therefore ensures that trace_clock_local() is invoked only
when CONFIG_RCU_TRACE=y.
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
If the previous CPU is cache affine and idle, select it.
The current implementation simply traverses the sd_llc domain,
taking the first idle CPU encountered, which walks buddy pairs
hand in hand over the package, inflicting excruciating pain.
1 tbench pair (worst case) in a 10 core + SMT package:
pre 15.22 MB/sec 1 procs
post 252.01 MB/sec 1 procs
Signed-off-by: Mike Galbraith <bitbucket@online.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1359371965.5783.127.camel@marge.simpson.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As no one is using the return value of irq_work_queue(),
so it is better to just make it void.
Signed-off-by: anish kumar <anish198519851985@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
[ Fix stale comments, remove now unnecessary __irq_work_queue() intermediate function ]
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1359925703-24304-1-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
mips was the last architecture not using the generic variant.
Both native and compat variants switched to generic, which is
made unconditional now.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
usual "call force_sigsegv or signal_delivered" logics. Takes
ksignal instead of separate siginfo/k_sigaction.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Again, protected by a temporary config symbol (GENERIC_COMPAT_RT_SIGACTION);
will be gone by the end of series.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
... and make it unconditional - we want the sucker on all biarch
platforms, really. All kinds of wrappers and private implementations
can go now; fortunately, they don't cause name conflicts, so we can
do that one first without any bisect hazards.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
conditional on GENERIC_COMPAT_RT_SIGQUEUEINFO; by the end of that series
it will become the same thing as COMPAT and conditional will die out.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Dan Carpenter
Frederic Weisbecker
Linus Torvalds
Thomas Gleixner
Tejun Heo
Sha Zhengju
Ingo Molnar
Konstantin Khlebnikov
Ben Greear
Namhyung Kim
Srivatsa S. Bhat
David S. Miller
Steven Rostedt (Red Hat)
Chris Metcalf
Li Zefan
H. Peter Anvin
Vineet Gupta
Vladimir Davydov
Rafael J. Wysocki
Stanislaw Gruszka
Daniel Baluta
Al Viro
Eric W. Biederman
Mark Rutland
Olof Johansson
Li Fei
Zhang Rui
Prarit Bhargava
Oleg Nesterov
Josh Stone
Dave Airlie
H. Peter Anvin
Lai Jiangshan
Clark Williams
Michał Mirosław
Stephen Hemminger
Leonid Shatz
Greg Kroah-Hartman
Mike Galbraith
anish kumar