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360776 Commits

Author SHA1 Message Date
Ingo Molnar a166fcf04d Merge branch 'timers/nohz-posix-timers-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into timers/nohz
Pull posix cpu timers handling on full dynticks from Frederic Weisbecker.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-21 11:05:47 +02:00
Ingo Molnar 2727872dfe Merge branch 'timers/nohz-reviewed' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into timers/nohz
Pull full dynticks timekeeping and RCU improvements from Frederic Weisbecker.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-21 11:04:42 +02:00
Frederic Weisbecker 555347f6c0 posix_timers: New API to prevent from stopping the tick when timers are running
Bring a new helper that the full dynticks infrastructure can
call in order to know if it can safely stop the tick from
the posix cpu timers subsystem point of view.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-19 16:31:40 +02:00
Frederic Weisbecker a85721601a posix_timers: Kick full dynticks CPUs when a posix cpu timer is armed
Kick the full dynticks CPUs when a posix cpu timer is enqueued by
way of a standard call to posix_cpu_timer_set() or set_process_cpu_timer().
This also include rescheduled firing timers.

This way they can re-evaluate the state of (and possibly restart) their
tick against the new expiry modification.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-19 16:30:13 +02:00
Frederic Weisbecker f98823ac75 nohz: New option to default all CPUs in full dynticks range
Provide a new kernel config that defaults all CPUs to be part
of the full dynticks range, except the boot one for timekeeping.

This default setting is overriden by the nohz_full= boot option
if passed by the user.

This is helpful for those who don't need a finegrained range
of full dynticks CPU and also for automated testing.

Suggested-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-19 13:54:16 +02:00
Frederic Weisbecker d1e43fa5f8 nohz: Ensure full dynticks CPUs are RCU nocbs
We need full dynticks CPU to also be RCU nocb so
that we don't have to keep the tick to handle RCU
callbacks.

Make sure the range passed to nohz_full= boot
parameter is a subset of rcu_nocbs=

The CPUs that fail to meet this requirement will be
excluded from the nohz_full range. This is checked
early in boot time, before any CPU has the opportunity
to stop its tick.

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-19 13:54:04 +02:00
Frederic Weisbecker 0453b435df nohz: Force boot CPU outside full dynticks range
The timekeeping job must be able to run early on boot
because there may be some pre-SMP (and thus pre-initcalls )
components that rely on it. The IO-APIC is one such users
as it tests the timer health by watching jiffies progression.

Given that it happens before we know the initial online
set, we can't rely on it to select a timekeeper. We need
one before SMP time otherwise we simply crash on boot.

To fix this and keep things simple for now, force the boot CPU
outside of the full dynticks range in any case and do this early
on kernel parameter parsing time.

We might want a trickier solution later, expecially for aSMP
architectures that need to assign housekeeping tasks to arbitrary
low power CPUs.

But it's still first pass KISS time for now.

Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-19 13:53:14 +02:00
Frederic Weisbecker 76c24fb054 nohz: New APIs to re-evaluate the tick on full dynticks CPUs
Provide two new helpers in order to notify the full dynticks CPUs about
some internal system changes against which they may reconsider the state
of their tick. Some practical examples include: posix cpu timers, perf tick
and sched clock tick.

For now the notifying handler, implemented through IPIs, is a stub
that will be implemented when we get the tick stop/restart infrastructure
in.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-18 18:53:34 +02:00
Paul E. McKenney 65d798f0f9 rcu: Kick adaptive-ticks CPUs that are holding up RCU grace periods
Adaptive-ticks CPUs inform RCU when they enter kernel mode, but they do
not necessarily turn the scheduler-clock tick back on.  This state of
affairs could result in RCU waiting on an adaptive-ticks CPU running
for an extended period in kernel mode.  Such a CPU will never run the
RCU state machine, and could therefore indefinitely extend the RCU state
machine, sooner or later resulting in an OOM condition.

This patch, inspired by an earlier patch by Frederic Weisbecker, therefore
causes RCU's force-quiescent-state processing to check for this condition
and to send an IPI to CPUs that remain in that state for too long.
"Too long" currently means about three jiffies by default, which is
quite some time for a CPU to remain in the kernel without blocking.
The rcu_tree.jiffies_till_first_fqs and rcutree.jiffies_till_next_fqs
sysfs variables may be used to tune "too long" if needed.

Reported-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-15 20:18:36 +02:00
Frederic Weisbecker fae30dd669 nohz: Improve a bit the full dynticks Kconfig documentation
Remove the "single task" statement from CONFIG_NO_HZ_FULL
title. The constraint can be invalidated when tasks from
other sched classes than SCHED_FAIR are running. Moreover
it's possible that hrtick join the party in the future.

Also add a line about the dependency on SMP.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-15 20:18:04 +02:00
Frederic Weisbecker 5b533f4ff5 nohz: Align periodic tick Kconfig with other choices' naming convention
Rename CONFIG_PERIODIC_HZ to CONFIG_HZ_PERIODIC in
order to stay consistent with other tick implementation
entries:

	CONFIG_HZ_PERIODIC
	CONFIG_NO_HZ_IDLE
	CONFIG_NO_HZ_FULL

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-15 20:11:26 +02:00
Frederic Weisbecker c5bfece2d6 nohz: Switch from "extended nohz" to "full nohz" based naming
"Extended nohz" was used as a naming base for the full dynticks
API and Kconfig symbols. It reflects the fact the system tries
to stop the tick in more places than just idle.

But that "extended" name is a bit opaque and vague. Rename it to
"full" makes it clearer what the system tries to do under this
config: try to shutdown the tick anytime it can. The various
constraints that prevent that to happen shouldn't be considered
as fundamental properties of this feature but rather technical
issues that may be solved in the future.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-15 19:58:17 +02:00
Frederic Weisbecker 0644ca5c77 nohz: Fix old dynticks idle Kconfig backward compatibility
In order to enforce backward compatibility with older
config files, we want the new dynticks-idle Kconfig entry
to default its value to the one of the old CONFIG_NO_HZ symbol
if present.

Namely we want:

	config NO_HZ # old obsolete dynticks idle symbol
		bool

	config NO_HZ_IDLE # new dynticks idle symbol
		default NO_HZ

However Kconfig prevents this to work if the old symbol
is not visible. And this is currently the case because
NO_HZ lacks a title in order to show it in make oldconfig
and alike.

To fix this, bring a minimal title and help text to the
obsolete Kconfig entry that explains its purpose. This
makes the "defaulting" to work.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-15 19:39:40 +02:00
Frederic Weisbecker 1034fc2f41 nohz: Print final full dynticks CPUs range on boot
Given that we apply a few restrictions on the full dynticks
CPUs range (keep an online timekeeper oustide the range,
then in the future have the range be an RCU nocb CPUs subset),
let's print the final resulting range of full dynticks CPUs to
the user so that he knows what's really going to run.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-03 14:00:48 +02:00
Frederic Weisbecker 3ca277e419 nohz: Pack nohz Kconfig option in a menu of choices
Now the user has the choice between three implementations of
the timer tick:

* Static periodic tick
* Idle dynticks
* Full dynticks

At least for now, these are mutually exclusive choices, so
let's rely on the proper Kconfig feature to display these
to the user.

A new entry CONFIG_NO_HZ_IDLE is created and the old
CONFIG_NO_HZ maps to it for config file backward compatibility.
The old name was too general now that we have more
granular dynticks implementations.

While at it, add some explanation to help the user on
his decision between the 3 entries.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-03 14:00:46 +02:00
Frederic Weisbecker 3451d0243c nohz: Rename CONFIG_NO_HZ to CONFIG_NO_HZ_COMMON
We are planning to convert the dynticks Kconfig options layout
into a choice menu. The user must be able to easily pick
any of the following implementations: constant periodic tick,
idle dynticks, full dynticks.

As this implies a mutual exclusion, the two dynticks implementions
need to converge on the selection of a common Kconfig option in order
to ease the sharing of a common infrastructure.

It would thus seem pretty natural to reuse CONFIG_NO_HZ to
that end. It already implements all the idle dynticks code
and the full dynticks depends on all that code for now.
So ideally the choice menu would propose CONFIG_NO_HZ_IDLE and
CONFIG_NO_HZ_EXTENDED then both would select CONFIG_NO_HZ.

On the other hand we want to stay backward compatible: if
CONFIG_NO_HZ is set in an older config file, we want to
enable CONFIG_NO_HZ_IDLE by default.

But we can't afford both at the same time or we run into
a circular dependency:

1) CONFIG_NO_HZ_IDLE and CONFIG_NO_HZ_EXTENDED both select
   CONFIG_NO_HZ
2) If CONFIG_NO_HZ is set, we default to CONFIG_NO_HZ_IDLE

We might be able to support that from Kconfig/Kbuild but it
may not be wise to introduce such a confusing behaviour.

So to solve this, create a new CONFIG_NO_HZ_COMMON option
which gathers the common code between idle and full dynticks
(that common code for now is simply the idle dynticks code)
and select it from their referring Kconfig.

Then we'll later create CONFIG_NO_HZ_IDLE and map CONFIG_NO_HZ
to it for backward compatibility.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-03 13:56:03 +02:00
Frederic Weisbecker ab71d36ddb nohz: Unhide full dynticks feature from its dependencies
The full dynticks feature only shows up when all its
Kconfig dependencies are met (RCU nocbs, RCU user mode, ...)

This is far from being user friendly as those who want to
activate this feature need to look into the Kconfig files
and iterate through each dependency then activate these
by hand in order to show and select the full dynticks
Kconfig option.

So process the other way around: show up the Kconfig option
if the minimal low level dependencies are met and activate
the high level ones when we enable the feature.

Note there is one exception in the picture:
CONFIG_VIRT_CPU_ACCOUNTING_GEN is part of a Kconfig choice
menu and it appears we can't select it from another Kconfig
selection when it's under such layout. So for now this
particular item stays as a passive dependency.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-02 20:30:43 +02:00
Frederic Weisbecker 1c20091e77 nohz: Wake up full dynticks CPUs when a timer gets enqueued
Wake up a CPU when a timer list timer is enqueued there and
the target is part of the full dynticks range. Sending an IPI
to it makes it reconsidering the next timer to program on top
of recent updates.

This may later be improved by checking if the tick is really
stopped on the target. This would need some careful
synchronization though. So deal with such optimization later
and start simple.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-03-21 15:55:59 +01:00
Frederic Weisbecker a382bf9344 nohz: Assign timekeeping duty to a CPU outside the full dynticks range
This way the full nohz CPUs can safely run with the tick
stopped with a guarantee that somebody else is taking
care of the jiffies and GTOD progression.

Once the duty is attributed to a CPU, it won't change. Also that
CPU can't enter into dyntick idle mode or be hot unplugged.

This may later be improved from a power consumption POV. At
least we should be able to share the duty amongst all CPUs
outside the full dynticks range. Then the duty could even be
shared with full dynticks CPUs when those can't stop their
tick for any reason.

But let's start with that very simple approach first.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
[fix have_nohz_full_mask offcase]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-03-21 15:55:45 +01:00
Frederic Weisbecker a831881be2 nohz: Basic full dynticks interface
For extreme usecases such as Real Time or HPC, having
the ability to shutdown the tick when a single task runs
on a CPU is a desired feature:

* Reducing the amount of interrupts improves throughput
for CPU-bound tasks. The CPU is less distracted from its
real job, from an execution time and from the cache point
of views.

* This also improve latency response as we have less critical
sections.

Start with introducing a very simple interface to define
full dynticks CPU: use a boot time option defined cpumask
through the "nohz_extended=" kernel parameter. CPUs that
are part of this range will have their tick shutdown
whenever possible: provided they run a single task and
they don't do kernel activity that require the periodic
tick. These details will be later documented in
Documentation/*

An online CPU must be kept outside this range to handle the
timekeeping.

Suggested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-03-21 15:38:33 +01:00
Peter Zijlstra a8d7ad52a7 sched/tracing: Allow tracing the preemption decision on wakeup
Thomas noted that we do the wakeup preemption check after the
wakeup trace point, this means the tracepoint cannot test/report
this decision; which is rather important for latency sensitive
workloads. Therefore move the tracepoint after doing the
preemption check.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Paul Turner <pjt@google.com>
Cc: Mike Galbraith <efault@gmx.de>
Link: http://lkml.kernel.org/r/1363254519.26965.9.camel@laptop
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-03-18 10:18:08 +01:00
Ingo Molnar e75c8b475e Merge branch 'sched/core' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into sched/core
Pull CPU runtime stats/accounting fixes from Frederic Weisbecker:

 " Some users are complaining that their threadgroup's runtime accounting
   freezes after a week or so of intense cpu-bound workload. This set tries
   to fix the issue by reducing the risk of multiplication overflow in the
   cputime scaling code. "

Stanislaw Gruszka further explained the historic context and impact of the
bug:

 " Commit 0cf55e1ec0 start to use scalling
   for whole thread group, so increase chances of hitting multiplication
   overflow, depending on how many CPUs are on the system.

   We have multiplication utime * rtime for one thread since commit
   b27f03d4bd.

   Overflow will happen after:

   rtime * utime > 0xffffffffffffffff jiffies

   if thread utilize 100% of CPU time, that gives:

   rtime > sqrt(0xffffffffffffffff) jiffies

   ritme > sqrt(0xffffffffffffffff) / (24 * 60 * 60 * HZ) days

   For HZ 100 it will be 497 days for HZ 1000 it will be 49 days.

   Bug affect only users, who run CPU intensive application for that
   long period. Also they have to be interested on utime,stime values,
   as bug has no other visible effect as making those values incorrect. "

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-03-18 10:09:31 +01:00
Andrei Epure 1bf08230f7 sched: Fix variable name misnomer, add comments
The min_vruntime variable actually stores the maximum value.
The added comment was taken from place_entity function.

Signed-off-by: Andrei Epure <epure.andrei@gmail.com>
Cc: peterz@infradead.org
Link: http://lkml.kernel.org/r/1363115544-1964-1-git-send-email-epure.andrei@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-03-14 08:22:29 +01:00
Frederic Weisbecker d9a3c9823a sched: Lower chances of cputime scaling overflow
Some users have reported that after running a process with
hundreds of threads on intensive CPU-bound loads, the cputime
of the group started to freeze after a few days.

This is due to how we scale the tick-based cputime against
the scheduler precise execution time value.

We add the values of all threads in the group and we multiply
that against the sum of the scheduler exec runtime of the whole
group.

This easily overflows after a few days/weeks of execution.

A proposed solution to solve this was to compute that multiplication
on stime instead of utime:
   62188451f0
   ("cputime: Avoid multiplication overflow on utime scaling")

The rationale behind that was that it's easy for a thread to
spend most of its time in userspace under intensive CPU-bound workload
but it's much harder to do CPU-bound intensive long run in the kernel.

This postulate got defeated when a user recently reported he was still
seeing cputime freezes after the above patch. The workload that
triggers this issue relates to intensive networking workloads where
most of the cputime is consumed in the kernel.

To reduce much more the opportunities for multiplication overflow,
lets reduce the multiplication factors to the remainders of the division
between sched exec runtime and cputime. Assuming the difference between
these shouldn't ever be that large, it could work on many situations.

This gets the same results as in the upstream scaling code except for
a small difference: the upstream code always rounds the results to
the nearest integer not greater to what would be the precise result.
The new code rounds to the nearest integer either greater or not
greater. In practice this difference probably shouldn't matter but
it's worth mentioning.

If this solution appears not to be enough in the end, we'll
need to partly revert back to the behaviour prior to commit
     0cf55e1ec0
     ("sched, cputime: Introduce thread_group_times()")

Back then, the scaling was done on exit() time before adding the cputime
of an exiting thread to the signal struct. And then we'll need to
scale one-by-one the live threads cputime in thread_group_cputime(). The
drawback may be a slightly slower code on exit time.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
2013-03-13 18:18:14 +01:00
Frederic Weisbecker f792685006 math64: New div64_u64_rem helper
Provide an extended version of div64_u64() that
also returns the remainder of the division.

We are going to need this to refine the cputime
scaling code.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
2013-03-13 18:03:27 +01:00
Andrei Epure 660cc00f8c sched: Spelling fix
Signed-off-by: Andrei Epure <epure.andrei@gmail.com>
Cc: trivial@kernel.org
Cc: peterz@infradead.org
Link: http://lkml.kernel.org/r/1362996200-2674-1-git-send-email-epure.andrei@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-03-11 15:12:11 +01:00
Li Zefan b719203b84 sched: Fix update_group_power() prototype placement to fix build warning when !CONFIG_SMP
All warnings:

   In file included from kernel/sched/core.c:85:0:
   kernel/sched/sched.h:1036:39: warning: 'struct sched_domain' declared inside parameter list
   kernel/sched/sched.h:1036:39: warning: its scope is only this definition or declaration, which is probably not what you want

It's because struct sched_domain is defined inside #if CONFIG_SMP,
while update_group_power() is declared unconditionally.

Fix this warning by declaring update_group_power() only if
CONFIG_SMP=n.

Build tested with CONFIG_SMP enabled and then disabled.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Li Zefan <lizefan@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/5137F4BA.2060101@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-03-11 09:07:24 +01:00
Ingo Molnar 4e3da46797 Merge branch 'sched/cputime' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into sched/core
Pull cputime changes from Frederic Weisbecker:

  * Generalize exception handling

  * Fix race in context tracking state restore on return from exception
    and irq exit kernel preemption

  * Fix cputime scaling in full dynticks accounting dynamic off-case

  * Fix default Kconfig value

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-03-08 16:41:22 +01:00
Frederic Weisbecker 8b43876643 context_tracking: Enable probes by default for selftesting
Until we provide the nohz_mask boot parameter, keeping
the context tracking probes disabled by default is pointless
since what we want is to runtime test this code anyway.

It's furthermore confusing for the users which don't expect
the probes to be off when they select RCU user mode or full
dynticks cputime accounting.

Let's enable these probes selftests by default for now.

Suggested: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Mats Liljegren <mats.liljegren@enea.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2013-03-07 17:10:41 +01:00
Frederic Weisbecker 9fbc42eac1 cputime: Dynamically scale cputime for full dynticks accounting
The full dynticks cputime accounting is able to account either
using the tick or the context tracking subsystem. This way
the housekeeping CPU can keep the low overhead tick based
solution.

This latter mode has a low jiffies resolution granularity and
need to be scaled against CFS precise runtime accounting to
improve its result. We are doing this for CONFIG_TICK_CPU_ACCOUNTING,
now we also need to expand it to full dynticks accounting dynamic
off-case as well.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Mats Liljegren <mats.liljegren@enea.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2013-03-07 17:10:32 +01:00
Frederic Weisbecker b22366cd54 context_tracking: Restore preempted context state after preempt_schedule_irq()
From the context tracking POV, preempt_schedule_irq() behaves pretty much
like an exception: It can be called anytime and schedule another task.

But currently it doesn't restore the context tracking state of the preempted
code on preempt_schedule_irq() return.

As a result, if preempt_schedule_irq() is called in the tiny frame between
user_enter() and the actual return to userspace, we resume userspace with
the wrong context tracking state.

Fix this by using exception_enter/exit() which are a perfect fit for this
kind of issue.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Mats Liljegren <mats.liljegren@enea.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2013-03-07 17:10:21 +01:00
Frederic Weisbecker 6c1e0256fa context_tracking: Restore correct previous context state on exception exit
On exception exit, we restore the previous context tracking state based on
the regs of the interrupted frame. Iff that frame is in user mode as
stated by user_mode() helper, we restore the context tracking user mode.

However there is a tiny chunck of low level arch code after we pass through
user_enter() and until the CPU eventually resumes userspace.
If an exception happens in this tiny area, exception_enter() correctly
exits the context tracking user mode but exception_exit() won't restore
it because of the value returned by user_mode(regs).

As a result we may return to userspace with the wrong context tracking
state.

To fix this, change exception_enter() to return the context tracking state
prior to its call and pass this saved state to exception_exit(). This restores
the real context tracking state of the interrupted frame.

(May be this patch was suggested to me, I don't recall exactly. If so,
sorry for the missing credit).

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Mats Liljegren <mats.liljegren@enea.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2013-03-07 17:10:11 +01:00
Frederic Weisbecker 56dd9470d7 context_tracking: Move exception handling to generic code
Exceptions handling on context tracking should share common
treatment: on entry we exit user mode if the exception triggered
in that context. Then on exception exit we return to that previous
context.

Generalize this to avoid duplication across archs.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Mats Liljegren <mats.liljegren@enea.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2013-03-07 17:09:25 +01:00
Li Zefan 27b4b9319a sched: Remove double declaration of root_task_group
It's already declared in include/linux/sched.h

Signed-off-by: Li Zefan <lizefan@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/5135A7D8.7000107@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-03-06 11:24:35 +01:00
Li Zefan 25cc7da7e6 sched: Move group scheduling functions out of include/linux/sched.h
- Make sched_group_{set_,}runtime(), sched_group_{set_,}period()
and sched_rt_can_attach() static.

- Move sched_{create,destroy,online,offline}_group() to
kernel/sched/sched.h.

- Remove declaration of sched_group_shares().

Signed-off-by: Li Zefan <lizefan@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/5135A7C5.3000708@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-03-06 11:24:34 +01:00
Li Zefan 15f803c94b sched: Make default_scale_freq_power() static
As default_scale_{freq,smt}_power() and update_rt_power() are
used in kernel/sched/fair.c only, annotate them as static
functions.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/5135A7AF.8010900@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-03-06 11:24:34 +01:00
Li Zefan c82ba9fa75 sched: Move struct sched_class to kernel/sched/sched.h
It's used internally only.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/5135A79F.8090502@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-03-06 11:24:33 +01:00
Li Zefan b13095f07f sched: Move wake flags to kernel/sched/sched.h
They are used internally only.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/5135A78E.7040609@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-03-06 11:24:32 +01:00
Li Zefan 5e6521eaa1 sched: Move struct sched_group to kernel/sched/sched.h
Move struct sched_group_power and sched_group and related inline
functions to kernel/sched/sched.h, as they are used internally
only.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/5135A77F.2010705@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-03-06 11:24:31 +01:00
Li Zefan cc1f4b1f3f sched: Move SCHED_LOAD_SHIFT macros to kernel/sched/sched.h
They are used internally only.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/5135A771.4070104@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-03-06 11:24:30 +01:00
Li Zefan 090b582f27 sched: Remove test_sd_parent()
It's unused.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/5135A75F.4070202@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-03-06 11:24:29 +01:00
Li Zefan 19a37d1cd5 sched: Remove some dummy functions
No one will call those functions if CONFIG_SCHED_DEBUG=n.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/5135A748.3050206@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-03-06 11:24:28 +01:00
Linus Torvalds 6dbe51c251 Linux 3.9-rc1 2013-03-03 15:11:05 -08:00
Linus Torvalds ea882c2ece UAPI disintegration 2012-12-20
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Merge tag 'disintegrate-fbdev-20121220' of git://git.infradead.org/users/dhowells/linux-headers

Pull fbdev UAPI disintegration from David Howells:
 "You'll be glad to here that the end is nigh for the UAPI patches.
  Only the fbdev/framebuffer piece remains now that the SCSI stuff has
  gone in.

  Here are the UAPI disintegration bits for the fbdev drivers.  It
  appears that Florian hasn't had time to deal with my patch, but back
  in December he did say he didn't mind if I pushed it forward."

Yay.  No more uapi movement.  And hopefully no more big header file
cleanups coming up either, it just tends to be very painful.

* tag 'disintegrate-fbdev-20121220' of git://git.infradead.org/users/dhowells/linux-headers:
  UAPI: (Scripted) Disintegrate include/video
2013-03-03 14:24:59 -08:00
Linus Torvalds 8e8b180a5f Bug-fixes:
- Update the Xen ACPI memory and CPU hotplug locking mechanism.
  - Fix PAT issues wherein various applications would not start
  - Fix handling of multiple MSI as AHCI now does it.
  - Fix ARM compile failures.
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Merge tag 'stable/for-linus-3.9-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

Pull Xen bug-fixes from Konrad Rzeszutek Wilk:
 - Update the Xen ACPI memory and CPU hotplug locking mechanism.
 - Fix PAT issues wherein various applications would not start
 - Fix handling of multiple MSI as AHCI now does it.
 - Fix ARM compile failures.

* tag 'stable/for-linus-3.9-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xenbus: fix compile failure on ARM with Xen enabled
  xen/pci: We don't do multiple MSI's.
  xen/pat: Disable PAT using pat_enabled value.
  xen/acpi: xen cpu hotplug minor updates
  xen/acpi: xen memory hotplug minor updates
2013-03-03 14:22:53 -08:00
Linus Torvalds 56a79b7b02 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull  more VFS bits from Al Viro:
 "Unfortunately, it looks like xattr series will have to wait until the
  next cycle ;-/

  This pile contains 9p cleanups and fixes (races in v9fs_fid_add()
  etc), fixup for nommu breakage in shmem.c, several cleanups and a bit
  more file_inode() work"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  constify path_get/path_put and fs_struct.c stuff
  fix nommu breakage in shmem.c
  cache the value of file_inode() in struct file
  9p: if v9fs_fid_lookup() gets to asking server, it'd better have hashed dentry
  9p: make sure ->lookup() adds fid to the right dentry
  9p: untangle ->lookup() a bit
  9p: double iput() in ->lookup() if d_materialise_unique() fails
  9p: v9fs_fid_add() can't fail now
  v9fs: get rid of v9fs_dentry
  9p: turn fid->dlist into hlist
  9p: don't bother with private lock in ->d_fsdata; dentry->d_lock will do just fine
  more file_inode() open-coded instances
  selinux: opened file can't have NULL or negative ->f_path.dentry

(In the meantime, the hlist traversal macros have changed, so this
required a semantic conflict fixup for the newly hlistified fid->dlist)
2013-03-03 13:23:03 -08:00
Linus Torvalds 1c82315a12 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixup from Chris Mason:
 "Geert and James both sent this one in, sorry guys"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs/raid56: Add missing #include <linux/vmalloc.h>
2013-03-03 13:13:20 -08:00
Linus Torvalds 530ede14cf Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull second set of s390 patches from Martin Schwidefsky:
 "The main part of this merge are Heikos uaccess patches.  Together with
  commit 0988496433 ("mm: do not grow the stack vma just because of an
  overrun on preceding vma") the user string access is hopefully fixed
  for good.

  In addition some bug fixes and two cleanup patches."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/module: fix compile warning
  qdio: remove unused parameters
  s390/uaccess: fix kernel ds access for page table walk
  s390/uaccess: fix strncpy_from_user string length check
  input: disable i8042 PC Keyboard controller for s390
  s390/dis: Fix invalid array size
  s390/uaccess: remove pointless access_ok() checks
  s390/uaccess: fix strncpy_from_user/strnlen_user zero maxlen case
  s390/uaccess: shorten strncpy_from_user/strnlen_user
  s390/dasd: fix unresponsive device after all channel paths were lost
  s390/mm: ignore change bit for vmemmap
  s390/page table dumper: add support for change-recording override bit
2013-03-03 12:58:43 -08:00
Linus Torvalds 6977c6fc77 Merge branch 'fixes-for-3.9-latest' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull second round of PARISC updates from Helge Deller:
 "The most important fix in this branch is the switch of io_setup,
  io_getevents and io_submit syscalls to use the available compat
  syscalls when running 32bit userspace on 64bit kernel.  Other than
  that it's mostly removal of compile warnings."

* 'fixes-for-3.9-latest' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: fix redefinition of SET_PERSONALITY
  parisc: do not install modules when installing kernel
  parisc: fix compile warnings triggered by atomic_sub(sizeof(),v)
  parisc: check return value of down_interruptible() in hp_sdc_rtc.c
  parisc: avoid unitialized variable warning in pa_memcpy()
  parisc: remove unused variable 'compat_val'
  parisc: switch to compat_functions of io_setup, io_getevents and io_submit
  parisc: select ARCH_WANT_FRAME_POINTERS
2013-03-03 12:57:38 -08:00
Linus Torvalds 8fd5e7a2d9 ImgTec Meta architecture changes for v3.9-rc1
This adds core architecture support for Imagination's Meta processor
 cores, followed by some later miscellaneous arch/metag cleanups and
 fixes which I kept separate to ease review:
 
  - Support for basic Meta 1 (ATP) and Meta 2 (HTP) core architecture
  - A few fixes all over, particularly for symbol prefixes
  - A few privilege protection fixes
  - Several cleanups (setup.c includes, split out a lot of metag_ksyms.c)
  - Fix some missing exports
  - Convert hugetlb to use vm_unmapped_area()
  - Copy device tree to non-init memory
  - Provide dma_get_sgtable()
 
 Signed-off-by: James Hogan <james.hogan@imgtec.com>
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Merge tag 'metag-v3.9-rc1-v4' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag

Pull new ImgTec Meta architecture from James Hogan:
 "This adds core architecture support for Imagination's Meta processor
  cores, followed by some later miscellaneous arch/metag cleanups and
  fixes which I kept separate to ease review:

   - Support for basic Meta 1 (ATP) and Meta 2 (HTP) core architecture
   - A few fixes all over, particularly for symbol prefixes
   - A few privilege protection fixes
   - Several cleanups (setup.c includes, split out a lot of
     metag_ksyms.c)
   - Fix some missing exports
   - Convert hugetlb to use vm_unmapped_area()
   - Copy device tree to non-init memory
   - Provide dma_get_sgtable()"

* tag 'metag-v3.9-rc1-v4' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag: (61 commits)
  metag: Provide dma_get_sgtable()
  metag: prom.h: remove declaration of metag_dt_memblock_reserve()
  metag: copy devicetree to non-init memory
  metag: cleanup metag_ksyms.c includes
  metag: move mm/init.c exports out of metag_ksyms.c
  metag: move usercopy.c exports out of metag_ksyms.c
  metag: move setup.c exports out of metag_ksyms.c
  metag: move kick.c exports out of metag_ksyms.c
  metag: move traps.c exports out of metag_ksyms.c
  metag: move irq enable out of irqflags.h on SMP
  genksyms: fix metag symbol prefix on crc symbols
  metag: hugetlb: convert to vm_unmapped_area()
  metag: export clear_page and copy_page
  metag: export metag_code_cache_flush_all
  metag: protect more non-MMU memory regions
  metag: make TXPRIVEXT bits explicit
  metag: kernel/setup.c: sort includes
  perf: Enable building perf tools for Meta
  metag: add boot time LNKGET/LNKSET check
  metag: add __init to metag_cache_probe()
  ...
2013-03-03 12:06:09 -08:00