nohz: Warn if the machine can not perform nohz_full

If the user configures NO_HZ_FULL and defines nohz_full=XXX on the
kernel command line, or enables NO_HZ_FULL_ALL, but nohz fails
due to the machine having a unstable clock, warn about it.

We do not want users thinking that they are getting the benefit
of nohz when their machine can not support it.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
watchdog: Register / unregister watchdog kthreads on sysctl control

The user activation/deactivation of the watchdog through boot parameters
or systcl is currently implemented with a dance involving kthreads parking
and unparking methods: the threads are unconditionally registered on
boot and they park as soon as the user want the watchdog to be disabled.

This method involves a few noisy details to handle though: the watchdog
kthreads may be unparked anytime due to hotplug operations, after which
the watchdog internals have to decide to park again if it is user-disabled.

As a result the setup() and unpark() methods need to be able to request a
reparking. This is not currently supported in the kthread infrastructure
so this piece of the watchdog code only works halfway.

Besides, unparking/reparking the watchdog kthreads consume unnecessary
cputime on hotplug operations when those could be simply ignored in the
first place.

As suggested by Srivatsa, let's instead only register the watchdog
threads when they are needed. This way we don't need to think about
hotplug operations and we don't burden the CPU onlining when the watchdog
is simply disabled.

Suggested-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Anish Singh <anish198519851985@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Don Zickus <dzickus@redhat.com>
watchdog: Rename confusing state variable

We have two very conflicting state variable names in the
watchdog:

* watchdog_enabled: This one reflects the user interface. It's
set to 1 by default and can be overriden with boot options
or sysctl/procfs interface.

* watchdog_disabled: This is the internal toggle state that
tells if watchdog threads, timers and NMI events are currently
running or not. This state mostly depends on the user settings.
It's a convenient state latch.

Now we really need to find clearer names because those
are just too confusing to encourage deep review.

watchdog_enabled now becomes watchdog_user_enabled to reflect
its purpose as an interface.

watchdog_disabled becomes watchdog_running to suggest its
role as a pure internal state.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Anish Singh <anish198519851985@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Don Zickus <dzickus@redhat.com>
watchdog: Boot-disable by default on full dynticks

When the watchdog runs, it prevents the full dynticks
CPUs from stopping their tick because the hard lockup
detector uses perf events internally, which in turn
rely on the periodic tick.

Since this is a rather confusing behaviour that is not
easy to track down and identify for those who want to
test CONFIG_NO_HZ_FULL, let's default disable the
watchdog on boot time when full dynticks is enabled.

The user can still enable it later on runtime using
proc or sysctl.

Reported-by: Steven Rostedt <rostedt@goodmis.org>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Anish Singh <anish198519851985@gmail.com>
nohz: Remove obsolete check for full dynticks CPUs to be RCU nocbs

Building full dynticks now implies that all CPUs are forced
into RCU nocb mode through CONFIG_RCU_NOCB_CPU_ALL.

The dynamic check has become useless.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Borislav Petkov <bp@alien8.de>
clocksource: Add Marvell Orion SoC timer

This patch add a DT enabled driver for timers found on Marvell Orion SoCs
(Kirkwood, Dove, Orion5x, and Discovery Innovation). It installs a free-
running clocksource on timer0 and a clockevent source on timer1.
Corresponding device tree documentation is also added.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
clocksource: arm_global_timer: Add ARM global timer support

This is a simple driver for the global timer module found in the Cortex
A9-MP cores from revision r1p0 onwards. This should be able to perform
the functions of the system timer and the local timer in an SMP system.

The global timer has the following features:
    The global timer is a 64-bit incrementing counter with an
auto-incrementing feature. It continues incrementing after sending
interrupts. The global timer is memory mapped in the private memory
region.
    The global timer is accessible to all Cortex-A9 processors in the
cluster. Each Cortex-A9 processor has a private 64-bit comparator that
is used to assert a private interrupt when the global timer has reached
the comparator value. All the Cortex-A9 processors in a design use the
banked ID, ID27, for this interrupt. ID27 is sent to the Interrupt
Controller as a Private Peripheral Interrupt. The global timer is
clocked by PERIPHCLK.

Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
CC: Arnd Bergmann <arnd@arndb.de>
CC: Rob Herring <robherring2@gmail.com>
CC: Linus Walleij <linus.walleij@linaro.org>
CC: Will Deacon <will.deacon@arm.com>
CC: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
irqchip: vt8500: Staticize local symbols

This driver is converted to use IRQCHIP_DECLARE and irqchip_init.
vt8500_handle_irq() and vt8500_irq_init() are only referenced in this file, so
make them static.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Tony Prisk <linux@prisktech.co.nz>
Cc: Olof Johansson <olof@lixom.net>
Link: http://lkml.kernel.org/r/1372995229.4038.1.camel@phoenix
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
irqchip: sun4i: Staticize sun4i_irq_ack()

sun4i_irq_ack() is only referenced in this file, so make it static.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: http://lkml.kernel.org/r/1373010070.14756.2.camel@phoenix
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
irqchip: nvic: Fix wrong num_ct argument for irq_alloc_domain_generic_chips()

The third parameter of irq_alloc_domain_generic_chips() is the number of
irq_chip_type instances associated with these chips rather than numbanks.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Cc: Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: kernel@pengutronix.de
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
genirq: generic chip: Use DIV_ROUND_UP to calculate numchips

The number of interrupts in a domain may be not divisible by the
number of interrupts each chip handles. Integer division may truncate
the result, thus use DIV_ROUND_UP to count numchips.

Seems all users of irq_alloc_domain_generic_chips() in current code do
not have this issue. I just found the issue while reading the code.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Link: http://lkml.kernel.org/r/1373015592.18252.2.camel@phoenix
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
irqchip: Add support for MOXA ART SoCs

This patch adds an irqchip driver for the main interrupt controller
found on MOXA ART SoCs.

Signed-off-by: Jonas Jensen <jonas.jensen@gmail.com>
Cc: grant.likely@secretlab.ca
Cc: thomas.petazzoni@free-electrons.com
Cc: arnd@arndb.de
Cc: u.kleine-koenig@pengutronix.de
Cc: linux@arm.linux.org.uk
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1372941531-6393-1-git-send-email-jonas.jensen@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
tools: Get only verbose output with V=1

Fix having verbose build with V=0, e.g:

 make V=0 -C tools/ perf

Signed-off-by: Robert Richter <robert.richter@calxeda.com>
Link: http://lkml.kernel.org/r/20130503134953.GU8356@rric.localhost
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf tools: Fix output directory of Documentation/

The OUTPUT directory is wrongly determind leading to:

 make[3]: *** No rule to make target `.../.build/perf/PERF-VERSION-FILE'.  Stop.

Fixing this by using the generic approach in script/Makefile.include.

Signed-off-by: Robert Richter <robert.richter@calxeda.com>
Link: http://lkml.kernel.org/r/1367865614-30876-1-git-send-email-rric@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf tools: Fix build errors with O and DESTDIR make vars set

Fixing build errors with O and DESTDIR make vars set:

 $ make prefix=/usr/local O=$builddir DESTDIR=$destdir -C tools/ perf
 ...
 make[1]: Entering directory `.../.source/perf/tools/perf'
     CC .../.build/perf/perf/util/parse-events.o
 util/parse-events.c:14:32: fatal error: parse-events-bison.h: No such file or directory
 compilation terminated.
 make[1]: *** [.../.build/perf/perf/util/parse-events.o] Error 1
 ...

and:

     LINK /.../.build/perf/perf/perf
 gcc: error: /.../.build/perf/perf//.../.source/perf/tools/lib/lk/liblk.a: No such file or directory

Signed-off-by: Robert Richter <robert.richter@linaro.org>
Signed-off-by: Robert Richter <rric@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Robert Richter <rric@kernel.org>
Link: http://lkml.kernel.org/r/1370964158-4135-1-git-send-email-rric@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf bench: Fix memory allocation fail check in mem{set,cpy} workloads

Addresses of allocated memory areas saved to '*src' and '*dst', so we
need to check them for NULL, not 'src' and 'dst'.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Hitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp>
Cc: Hitoshi Mitake <h.mitake@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/1370518503-4230-1-git-send-email-kirill.shutemov@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf tools: Include termios.h explicitly

Building perf for android fails because it can't find the definition of
struct winsize.

This definition is in termios.h, so I add this header to util.h to solve
the problem.

It is missed by commit '2c803e52' which moves get_term_dimensions() from
builtin-top.c to util.c, but missed to move termios.h header.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: David Ahern <dsahern@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1371603750-15053-3-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
tools lib lk: Fix for cross build

Currently, lib lk doesn't use CROSS_COMPILE environment variable, so
cross build always fails.

This is a quick fix for this problem.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1371603750-15053-2-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf stat: Avoid sending SIGTERM to random processes

This patch fixes a problem with perf stat whereby on termination it may
send a SIGTERM signal to random processes on systems with high PID
recycling. I got some actual bug reports on this.

There is race between the SIGCHLD and sig_atexit() handlers.  This patch
addresses this problem by clearing child_pid in the SIGCHLD handler.

Signed-off-by: Stephane Eranian <eranian@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20130604154426.GA2928@quad
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf record: Remove -A/--append option

It's no longer working and needed.

Quite straightforward discussion/vote was in here:
http://marc.info/?t=137028288300004&r=1&w=2

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-8fgdva12hl8w3xzzpsvvg7nx@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>