firefly-linux-kernel-4.4.55.git
10 years agoarm64: Remove TIF_POLLING_NRFLAG
Peter Zijlstra [Fri, 9 May 2014 17:04:00 +0000 (19:04 +0200)]
arm64: Remove TIF_POLLING_NRFLAG

The only idle method for arm64 is WFI and it therefore
unconditionally requires the reschedule interrupt when idle.

Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: http://lkml.kernel.org/r/20140509170649.GG13658@twins.programming.kicks-ass.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agometag: Remove TIF_POLLING_NRFLAG
James Hogan [Fri, 9 May 2014 14:36:21 +0000 (15:36 +0100)]
metag: Remove TIF_POLLING_NRFLAG

The Meta idle function jumps into the interrupt handler which
efficiently blocks waiting for the next interrupt when it reads the
interrupt status register (TXSTATI). No other (polling) idle functions
can be used, therefore TIF_POLLING_NRFLAG is unnecessary, so lets remove
it.

Peter Zijlstra said:
> Most archs have (x86) hlt or (arm) wfi like idle instructions, and if
> that is your only possible idle function, you'll require the interrupt
> to wake up and there's really no point to having the POLLING bit.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/536CEB7E.9080007@imgtec.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched/idle: Make cpuidle_idle_call() void
Rafael J. Wysocki [Sun, 20 Apr 2014 23:26:58 +0000 (01:26 +0200)]
sched/idle: Make cpuidle_idle_call() void

The only value ever returned by cpuidle_idle_call() is 0 and its
only caller ignores that value anyway, so make it void.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/4717784.WmVEpDoliM@vostro.rjw.lan
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched/idle: Reflow cpuidle_idle_call()
Peter Zijlstra [Fri, 11 Apr 2014 11:55:48 +0000 (13:55 +0200)]
sched/idle: Reflow cpuidle_idle_call()

Apply goto to reduce lines and nesting levels.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-cc6vb0snt3sr7op6rlbfeqfh@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched/idle: Delay clearing the polling bit
Peter Zijlstra [Fri, 11 Apr 2014 11:47:16 +0000 (13:47 +0200)]
sched/idle: Delay clearing the polling bit

With the generic idle functions assuming !polling we should only clear
the polling bit at the very last opportunity in order to avoid
spurious IPIs.

Ideally we'd flip the default to polling, but that means auditing all
arch idle functions.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-vq7719foqzf6z5h4j7eh7f9e@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched/idle: Avoid spurious wakeup IPIs
Peter Zijlstra [Wed, 9 Apr 2014 13:35:08 +0000 (15:35 +0200)]
sched/idle: Avoid spurious wakeup IPIs

Because mwait_idle_with_hints() gets called from !idle context it must
call current_clr_polling(). This however means that resched_task() is
very likely to send an IPI even when we were polling:

  CPU0 CPU1

  if (current_set_polling_and_test())
    goto out;

  __monitor(&ti->flags);
  if (!need_resched())
    __mwait(eax, ecx);
set_tsk_need_resched(p);
smp_mb();
out:
  current_clr_polling();
if (!tsk_is_polling(p))
  smp_send_reschedule(cpu);

So while it is correct (extra IPIs aren't a problem, whereas a missed
IPI would be) it is a performance problem (for some).

Avoid this issue by using fetch_or() to atomically set NEED_RESCHED
and test if POLLING_NRFLAG is set.

Since a CPU stuck in mwait is unlikely to modify the flags word,
contention on the cmpxchg is unlikely and thus we should mostly
succeed in a single go.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-kf5suce6njh5xf5d3od13rr0@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched/idle: Remove TS_POLLING support
Peter Zijlstra [Wed, 9 Apr 2014 12:30:10 +0000 (14:30 +0200)]
sched/idle: Remove TS_POLLING support

Now that there are no architectures left using it, kill the support
for TS_POLLING.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/n/tip-6yurip2tfix2f4bfc5agu2s0@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched/idle, x86: Switch from TS_POLLING to TIF_POLLING_NRFLAG
Peter Zijlstra [Fri, 11 Apr 2014 07:59:05 +0000 (09:59 +0200)]
sched/idle, x86: Switch from TS_POLLING to TIF_POLLING_NRFLAG

Standardize the idle polling indicator to TIF_POLLING_NRFLAG such that
both TIF_NEED_RESCHED and TIF_POLLING_NRFLAG are in the same word.
This will allow us, using fetch_or(), to both set NEED_RESCHED and
check for POLLING_NRFLAG in a single operation and avoid pointless
wakeups.

Changing from the non-atomic thread_info::status flags to the atomic
thread_info::flags shouldn't be a big issue since most polling state
changes were followed/preceded by a full memory barrier anyway.

Also, fix up the apm_32 idle function, clearly that was forgotten in
the last conversion. The default idle state is !POLLING so just kill
the lot.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Link: http://lkml.kernel.org/n/tip-7yksmqtlv4nfowmlqr1rifoi@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched/idle, ia64: Switch from TS_POLLING to TIF_POLLING_NRFLAG
Peter Zijlstra [Fri, 11 Apr 2014 07:59:08 +0000 (09:59 +0200)]
sched/idle, ia64: Switch from TS_POLLING to TIF_POLLING_NRFLAG

Standardize the idle polling indicator to TIF_POLLING_NRFLAG such that
both TIF_NEED_RESCHED and TIF_POLLING_NRFLAG are in the same word.
This will allow us, using fetch_or(), to both set NEED_RESCHED and
check for POLLING_NRFLAG in a single operation and avoid pointless
wakeups.

Changing from the non-atomic thread_info::status flags to the atomic
thread_info::flags shouldn't be a big issue since most polling state
changes were followed/preceded by a full memory barrier anyway.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: linux-ia64@vger.kernel.org
Link: http://lkml.kernel.org/n/tip-6633akuird5hi3si4gbegkm8@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched/idle, tile: Switch from TS_POLLING to TIF_POLLING_NRFLAG
Peter Zijlstra [Fri, 11 Apr 2014 07:59:13 +0000 (09:59 +0200)]
sched/idle, tile: Switch from TS_POLLING to TIF_POLLING_NRFLAG

Standardize the idle polling indicator to TIF_POLLING_NRFLAG such that
both TIF_NEED_RESCHED and TIF_POLLING_NRFLAG are in the same word.
This will allow us, using fetch_or(), to both set NEED_RESCHED and
check for POLLING_NRFLAG in a single operation and avoid pointless
wakeups.

Changing from the non-atomic thread_info::status flags to the atomic
thread_info::flags shouldn't be a big issue since most polling state
changes were followed/preceded by a full memory barrier anyway.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-35zzwlvwr7cp8xj196y10yyx@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched/idle, alpha: Switch from TS_POLLING to TIF_POLLING_NRFLAG
Peter Zijlstra [Fri, 11 Apr 2014 07:59:17 +0000 (09:59 +0200)]
sched/idle, alpha: Switch from TS_POLLING to TIF_POLLING_NRFLAG

Standardize the idle polling indicator to TIF_POLLING_NRFLAG such that
both TIF_NEED_RESCHED and TIF_POLLING_NRFLAG are in the same word.
This will allow us, using fetch_or(), to both set NEED_RESCHED and
check for POLLING_NRFLAG in a single operation and avoid pointless
wakeups.

Changing from the non-atomic thread_info::status flags to the atomic
thread_info::flags shouldn't be a big issue since most polling state
changes were followed/preceded by a full memory barrier anyway.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Richard Henderson <rth@twiddle.net>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: 蔡正龙 <zhenglong.cai@cs2c.com.cn>
Cc: linux-alpha@vger.kernel.org
Link: http://lkml.kernel.org/n/tip-9tfzr196gs0n2afxv0ga8pc3@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched/fair: Stop searching for tasks in newidle balance if there are runnable tasks
Jason Low [Thu, 24 Apr 2014 01:30:35 +0000 (18:30 -0700)]
sched/fair: Stop searching for tasks in newidle balance if there are runnable tasks

It was found that when running some workloads (such as AIM7) on large
systems with many cores, CPUs do not remain idle for long. Thus, tasks
can wake/get enqueued while doing idle balancing.

In this patch, while traversing the domains in idle balance, in
addition to checking for pulled_task, we add an extra check for
this_rq->nr_running for determining if we should stop searching for
tasks to pull. If there are runnable tasks on this rq, then we will
stop traversing the domains. This reduces the chance that idle balance
delays a task from running.

This patch resulted in approximately a 6% performance improvement when
running a Java Server workload on an 8 socket machine.

Signed-off-by: Jason Low <jason.low2@hp.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: daniel.lezcano@linaro.org
Cc: alex.shi@linaro.org
Cc: preeti@linux.vnet.ibm.com
Cc: efault@gmx.de
Cc: vincent.guittot@linaro.org
Cc: morten.rasmussen@arm.com
Cc: aswin@hp.com
Cc: chegu_vinod@hp.com
Link: http://lkml.kernel.org/r/1398303035-18255-4-git-send-email-jason.low2@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched, ARM: Create a dedicated scheduler topology table
Vincent Guittot [Fri, 11 Apr 2014 09:44:41 +0000 (11:44 +0200)]
sched, ARM: Create a dedicated scheduler topology table

Create a dedicated topology table for ARM which will create new level to
differentiate CPUs that can or not powergate independantly from others.

The patch gives an example of how to add domain that will take advantage of
SD_SHARE_POWERDOMAIN.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Brown <broonie@linaro.org>
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
Cc: devicetree@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: tony.luck@intel.com
Cc: fenghua.yu@intel.com
Cc: schwidefsky@de.ibm.com
Cc: cmetcalf@tilera.com
Cc: benh@kernel.crashing.org
Cc: preeti@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/1397209481-28542-6-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched: Add a new SD_SHARE_POWERDOMAIN for sched_domain
Vincent Guittot [Fri, 11 Apr 2014 09:44:40 +0000 (11:44 +0200)]
sched: Add a new SD_SHARE_POWERDOMAIN for sched_domain

A new flag SD_SHARE_POWERDOMAIN is created to reflect whether groups of CPUs
in a sched_domain level can or not reach different power state. As an example,
the flag should be cleared at CPU level if groups of cores can be power gated
independently. This information can be used in the load balance decision or to
add load balancing level between group of CPUs that can power gate
independantly.
This flag is part of the topology flags that can be set by arch.

Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: tony.luck@intel.com
Cc: fenghua.yu@intel.com
Cc: schwidefsky@de.ibm.com
Cc: cmetcalf@tilera.com
Cc: benh@kernel.crashing.org
Cc: preeti@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/1397209481-28542-5-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched, powerpc: Create a dedicated topology table
Vincent Guittot [Fri, 11 Apr 2014 09:44:39 +0000 (11:44 +0200)]
sched, powerpc: Create a dedicated topology table

Create a dedicated topology table for handling asymetric feature of powerpc.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Fleming <afleming@freescale.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Preeti U. Murthy <preeti@linux.vnet.ibm.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Cc: tony.luck@intel.com
Cc: fenghua.yu@intel.com
Cc: schwidefsky@de.ibm.com
Cc: cmetcalf@tilera.com
Cc: dietmar.eggemann@arm.com
Cc: devicetree@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/1397209481-28542-4-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched, s390: Create a dedicated topology table
Vincent Guittot [Fri, 11 Apr 2014 09:44:38 +0000 (11:44 +0200)]
sched, s390: Create a dedicated topology table

BOOK level is only relevant for s390 so we create a dedicated topology table
with BOOK level and remove it from default table.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Philipp Hachtmann <phacht@linux.vnet.ibm.com>
Cc: cmetcalf@tilera.com
Cc: benh@kernel.crashing.org
Cc: dietmar.eggemann@arm.com
Cc: preeti@linux.vnet.ibm.com
Cc: tony.luck@intel.com
Cc: fenghua.yu@intel.com
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
Link: http://lkml.kernel.org/r/1397209481-28542-3-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched: Rework sched_domain topology definition
Vincent Guittot [Fri, 11 Apr 2014 09:44:37 +0000 (11:44 +0200)]
sched: Rework sched_domain topology definition

We replace the old way to configure the scheduler topology with a new method
which enables a platform to declare additionnal level (if needed).

We still have a default topology table definition that can be used by platform
that don't want more level than the SMT, MC, CPU and NUMA ones. This table can
be overwritten by an arch which either wants to add new level where a load
balance make sense like BOOK or powergating level or wants to change the flags
configuration of some levels.

For each level, we need a function pointer that returns cpumask for each cpu,
a function pointer that returns the flags for the level and a name. Only flags
that describe topology, can be set by an architecture. The current topology
flags are:

 SD_SHARE_CPUPOWER
 SD_SHARE_PKG_RESOURCES
 SD_NUMA
 SD_ASYM_PACKING

Then, each level must be a subset on the next one. The build sequence of the
sched_domain will take care of removing useless levels like those with 1 CPU
and those with the same CPU span and no more relevant information for
load balancing than its children.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jason Low <jason.low2@hp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux390@de.ibm.com
Cc: linux-ia64@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Link: http://lkml.kernel.org/r/1397209481-28542-2-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agomm/numa: Remove BUG_ON() in __handle_mm_fault()
Rik van Riel [Tue, 29 Apr 2014 19:36:15 +0000 (15:36 -0400)]
mm/numa: Remove BUG_ON() in __handle_mm_fault()

Changing PTEs and PMDs to pte_numa & pmd_numa is done with the
mmap_sem held for reading, which means a pmd can be instantiated
and turned into a numa one while __handle_mm_fault() is examining
the value of old_pmd.

If that happens, __handle_mm_fault() should just return and let
the page fault retry, instead of throwing an oops. This is
handled by the test for pmd_trans_huge(*pmd) below.

Signed-off-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reported-by: Sunil Pandey <sunil.k.pandey@intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: linux-mm@kvack.org
Cc: lwoodman@redhat.com
Cc: dave.hansen@intel.com
Link: http://lkml.kernel.org/r/20140429153615.2d72098e@annuminas.surriel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched/numa: Do not set preferred_node on migration to a second choice node
Rik van Riel [Fri, 11 Apr 2014 17:00:29 +0000 (13:00 -0400)]
sched/numa: Do not set preferred_node on migration to a second choice node

Setting the numa_preferred_node for a task in task_numa_migrate
does nothing on a 2-node system. Either we migrate to the node
that already was our preferred node, or we stay where we were.

On a 4-node system, it can slightly decrease overhead, by not
calling the NUMA code as much. Since every node tends to be
directly connected to every other node, running on the wrong
node for a while does not do much damage.

However, on an 8 node system, there are far more bad nodes
than there are good ones, and pretending that a second choice
is actually the preferred node can greatly delay, or even
prevent, a workload from converging.

The only time we can safely pretend that a second choice
node is the preferred node is when the task is part of a
workload that spans multiple NUMA nodes.

Signed-off-by: Rik van Riel <riel@redhat.com>
Tested-by: Vinod Chegu <chegu_vinod@hp.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1397235629-16328-4-git-send-email-riel@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched/numa: Retry placement more frequently when misplaced
Rik van Riel [Fri, 11 Apr 2014 17:00:28 +0000 (13:00 -0400)]
sched/numa: Retry placement more frequently when misplaced

When tasks have not converged on their preferred nodes yet, we want
to retry fairly often, to make sure we do not migrate a task's memory
to an undesirable location, only to have to move it again later.

This patch reduces the interval at which migration is retried,
when the task's numa_scan_period is small.

Signed-off-by: Rik van Riel <riel@redhat.com>
Tested-by: Vinod Chegu <chegu_vinod@hp.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1397235629-16328-3-git-send-email-riel@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched/numa: Count pages on active node as local
Rik van Riel [Fri, 11 Apr 2014 17:00:27 +0000 (13:00 -0400)]
sched/numa: Count pages on active node as local

The NUMA code is smart enough to distribute the memory of workloads
that span multiple NUMA nodes across those NUMA nodes.

However, it still has a pretty high scan rate for such workloads,
because any memory that is left on a node other than the node of
the CPU that faulted on the memory is counted as non-local, which
causes the scan rate to go up.

Counting the memory on any node where the task's numa group is
actively running as local, allows the scan rate to slow down
once the application is settled in.

This should reduce the overhead of the automatic NUMA placement
code, when a workload spans multiple NUMA nodes.

Signed-off-by: Rik van Riel <riel@redhat.com>
Tested-by: Vinod Chegu <chegu_vinod@hp.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1397235629-16328-2-git-send-email-riel@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agoMerge branch 'sched/urgent' into sched/core, to avoid conflicts
Ingo Molnar [Wed, 7 May 2014 11:15:46 +0000 (13:15 +0200)]
Merge branch 'sched/urgent' into sched/core, to avoid conflicts

Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched/numa: Initialize newidle balance stats in sd_numa_init()
Jason Low [Thu, 24 Apr 2014 01:30:34 +0000 (18:30 -0700)]
sched/numa: Initialize newidle balance stats in sd_numa_init()

Also initialize the per-sd variables for newidle load balancing
in sd_numa_init().

Signed-off-by: Jason Low <jason.low2@hp.com>
Acked-by: morten.rasmussen@arm.com
Cc: daniel.lezcano@linaro.org
Cc: alex.shi@linaro.org
Cc: preeti@linux.vnet.ibm.com
Cc: efault@gmx.de
Cc: vincent.guittot@linaro.org
Cc: aswin@hp.com
Cc: chegu_vinod@hp.com
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1398303035-18255-3-git-send-email-jason.low2@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched: Fix updating rq->max_idle_balance_cost and rq->next_balance in idle_balance()
Jason Low [Mon, 28 Apr 2014 22:45:54 +0000 (15:45 -0700)]
sched: Fix updating rq->max_idle_balance_cost and rq->next_balance in idle_balance()

The following commit:

  e5fc66119ec9 ("sched: Fix race in idle_balance()")

can potentially cause rq->max_idle_balance_cost to not be updated,
even when load_balance(NEWLY_IDLE) is attempted and the per-sd
max cost value is updated.

Preeti noticed a similar issue with updating rq->next_balance.

In this patch, we fix this by making sure we still check/update those values
even if a task gets enqueued while browsing the domains.

Signed-off-by: Jason Low <jason.low2@hp.com>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: morten.rasmussen@arm.com
Cc: aswin@hp.com
Cc: daniel.lezcano@linaro.org
Cc: alex.shi@linaro.org
Cc: efault@gmx.de
Cc: vincent.guittot@linaro.org
Link: http://lkml.kernel.org/r/1398725155-7591-2-git-send-email-jason.low2@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched: Skip double execution of pick_next_task_fair()
Peter Zijlstra [Thu, 24 Apr 2014 10:00:47 +0000 (12:00 +0200)]
sched: Skip double execution of pick_next_task_fair()

Tim wrote:

 "The current code will call pick_next_task_fair a second time in the
  slow path if we did not pull any task in our first try.  This is
  really unnecessary as we already know no task can be pulled and it
  doubles the delay for the cpu to enter idle.

  We instrumented some network workloads and that saw that
  pick_next_task_fair is frequently called twice before a cpu enters
  idle.  The call to pick_next_task_fair can add non trivial latency as
  it calls load_balance which runs find_busiest_group on an hierarchy of
  sched domains spanning the cpus for a large system.  For some 4 socket
  systems, we saw almost 0.25 msec spent per call of pick_next_task_fair
  before a cpu can be idled."

Optimize the second call away for the common case and document the
dependency.

Reported-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Len Brown <len.brown@intel.com>
Link: http://lkml.kernel.org/r/20140424100047.GP11096@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched: Use CPUPRI_NR_PRIORITIES instead of MAX_RT_PRIO in cpupri check
Steven Rostedt (Red Hat) [Sun, 13 Apr 2014 13:34:53 +0000 (09:34 -0400)]
sched: Use CPUPRI_NR_PRIORITIES instead of MAX_RT_PRIO in cpupri check

The check at the beginning of cpupri_find() makes sure that the task_pri
variable does not exceed the cp->pri_to_cpu array length. But that length
is CPUPRI_NR_PRIORITIES not MAX_RT_PRIO, where it will miss the last two
priorities in that array.

As task_pri is computed from convert_prio() which should never be bigger
than CPUPRI_NR_PRIORITIES, if the check should cause a panic if it is
hit.

Reported-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1397015410.5212.13.camel@marge.simpson.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched/deadline: Fix memory leak
Li Zefan [Thu, 17 Apr 2014 02:05:02 +0000 (10:05 +0800)]
sched/deadline: Fix memory leak

Free cpudl->free_cpus allocated in cpudl_init().

Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Juri Lelli <juri.lelli@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org> # 3.14+
Link: http://lkml.kernel.org/r/534F36CE.2000409@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched/deadline: Fix sched_yield() behavior
Juri Lelli [Tue, 15 Apr 2014 11:49:04 +0000 (13:49 +0200)]
sched/deadline: Fix sched_yield() behavior

yield_task_dl() is broken:

 o it forces current to be throttled setting its runtime to zero;
 o it sets current's dl_se->dl_new to one, expecting that dl_task_timer()
   will queue it back with proper parameters at replenish time.

Unfortunately, dl_task_timer() has this check at the very beginning:

if (!dl_task(p) || dl_se->dl_new)
goto unlock;

So, it just bails out and the task is never replenished. It actually
yielded forever.

To fix this, introduce a new flag indicating that the task properly yielded
the CPU before its current runtime expired. While this is a little overdoing
at the moment, the flag would be useful in the future to discriminate between
"good" jobs (of which remaining runtime could be reclaimed, i.e. recycled)
and "bad" jobs (for which dl_throttled task has been set) that needed to be
stopped.

Reported-by: yjay.kim <yjay.kim@lge.com>
Signed-off-by: Juri Lelli <juri.lelli@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140429103953.e68eba1b2ac3309214e3dc5a@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched: Sanitize irq accounting madness
Thomas Gleixner [Fri, 2 May 2014 21:26:24 +0000 (23:26 +0200)]
sched: Sanitize irq accounting madness

Russell reported, that irqtime_account_idle_ticks() takes ages due to:

       for (i = 0; i < ticks; i++)
               irqtime_account_process_tick(current, 0, rq);

It's sad, that this code was written way _AFTER_ the NOHZ idle
functionality was available. I charge myself guitly for not paying
attention when that crap got merged with commit abb74cefa ("sched:
Export ns irqtimes through /proc/stat")

So instead of looping nr_ticks times just apply the whole thing at
once.

As a side note: The whole cputime_t vs. u64 business in that context
wants to be cleaned up as well. There is no point in having all these
back and forth conversions. Lets standardise on u64 nsec for all
kernel internal accounting and be done with it. Everything else does
not make sense at all for fine grained accounting. Frederic, can you
please take care of that?

Reported-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Venkatesh Pallipadi <venki@google.com>
Cc: Shaun Ruffell <sruffell@digium.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1405022307000.6261@ionos.tec.linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched/docbook: Fix 'make htmldocs' warnings caused by missing description
Masanari Iida [Thu, 17 Apr 2014 16:59:15 +0000 (01:59 +0900)]
sched/docbook: Fix 'make htmldocs' warnings caused by missing description

When 'flags' argument to sched_{set,get}attr() syscalls were
added in:

  6d35ab48090b ("sched: Add 'flags' argument to sched_{set,get}attr() syscalls")

no description for 'flags' was added. It causes the following warnings on "make htmldocs":

  Warning(/kernel/sched/core.c:3645): No description found for parameter 'flags'
  Warning(/kernel/sched/core.c:3789): No description found for parameter 'flags'

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Cc: peterz@infradead.org
Link: http://lkml.kernel.org/r/1397753955-2914-1-git-send-email-standby24x7@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agoMerge tag 'gpio-v3.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw...
Linus Torvalds [Tue, 22 Apr 2014 16:28:02 +0000 (09:28 -0700)]
Merge tag 'gpio-v3.15-2' of git://git./linux/kernel/git/linusw/linux-gpio

Pull gpio fixes from Linus Walleij:
 "A small batch of GPIO fixes for the v3.15 series.  I expect more to
  come in but I'm a bit behind on mail, might as well get these to you
  right now:

   - Change a crucial semantic ordering in the GPIO irqchip helpers

   - Fix two nasty regressions in the ACPI gpiolib extensions"

* tag 'gpio-v3.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio / ACPI: Prevent potential wrap of GPIO value on OpRegion read
  gpio / ACPI: Don't crash on NULL chip->dev
  gpio: set data first, then chip and handler

10 years agoMerge branch 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Tue, 22 Apr 2014 16:09:06 +0000 (09:09 -0700)]
Merge branch 'x86-vdso-for-linus' of git://git./linux/kernel/git/tip/tip

Pull x86 vdso fix from Peter Anvin:
 "This is a single build fix for building with gold as opposed to GNU
  ld.  It got queued up separately and was expected to be pushed during
  the merge window, but it got left behind"

* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, vdso: Make the vdso linker script compatible with Gold

10 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml
Linus Torvalds [Mon, 21 Apr 2014 17:05:35 +0000 (10:05 -0700)]
Merge branch 'for-linus' of git://git./linux/kernel/git/rw/uml

Pull UML fixes from Richard Weinberger:
 "Assorted fixes for UML"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: Memory corruption on startup
  um: Missing pipe handling
  uml: Simplify tempdir logic.

10 years agoMerge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Mon, 21 Apr 2014 03:43:47 +0000 (20:43 -0700)]
Merge tag 'ext4_for_linus_stable' of git://git./linux/kernel/git/tytso/ext4

Pull ext4 fixes from Ted Ts'o:
 "These are regression and bug fixes for ext4.

  We had a number of new features in ext4 during this merge window
  (ZERO_RANGE and COLLAPSE_RANGE fallocate modes, renameat, etc.) so
  there were many more regression and bug fixes this time around.  It
  didn't help that xfstests hadn't been fully updated to fully stress
  test COLLAPSE_RANGE until after -rc1"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (31 commits)
  ext4: disable COLLAPSE_RANGE for bigalloc
  ext4: fix COLLAPSE_RANGE failure with 1KB block size
  ext4: use EINVAL if not a regular file in ext4_collapse_range()
  ext4: enforce we are operating on a regular file in ext4_zero_range()
  ext4: fix extent merging in ext4_ext_shift_path_extents()
  ext4: discard preallocations after removing space
  ext4: no need to truncate pagecache twice in collapse range
  ext4: fix removing status extents in ext4_collapse_range()
  ext4: use filemap_write_and_wait_range() correctly in collapse range
  ext4: use truncate_pagecache() in collapse range
  ext4: remove temporary shim used to merge COLLAPSE_RANGE and ZERO_RANGE
  ext4: fix ext4_count_free_clusters() with EXT4FS_DEBUG and bigalloc enabled
  ext4: always check ext4_ext_find_extent result
  ext4: fix error handling in ext4_ext_shift_extents
  ext4: silence sparse check warning for function ext4_trim_extent
  ext4: COLLAPSE_RANGE only works on extent-based files
  ext4: fix byte order problems introduced by the COLLAPSE_RANGE patches
  ext4: use i_size_read in ext4_unaligned_aio()
  fs: disallow all fallocate operation on active swapfile
  fs: move falloc collapse range check into the filesystem methods
  ...

10 years agoum: Memory corruption on startup
Anton Ivanov [Fri, 7 Mar 2014 18:37:47 +0000 (18:37 +0000)]
um: Memory corruption on startup

The reverse case of this race (you must msync before read) is
well known. This is the not so common one.

It can be triggered only on systems which do a lot of task
switching and only at UML startup. If you are starting 200+ UMLs
~ 0.5% will always die without this fix.

Signed-off-by: Anton Ivanov <antivano@cisco.com>
[rw: minor whitespace fixes]
Signed-off-by: Richard Weinberger <richard@nod.at>
10 years agoum: Missing pipe handling
Anton Ivanov [Fri, 7 Mar 2014 18:37:46 +0000 (18:37 +0000)]
um: Missing pipe handling

UML does not handle sigpipe. As a result when running it under
expect or redirecting the IO from the console to an external program
it will crash if the program stops or exits.

Signed-off-by: Anton Ivanov <antivano@cisco.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
10 years agouml: Simplify tempdir logic.
Tristan Schmelcher [Mon, 11 Nov 2013 18:03:06 +0000 (13:03 -0500)]
uml: Simplify tempdir logic.

Inferring the mount hierarchy correctly from /proc/mounts is hard when MS_MOVE
may have been used, and the previous code did it wrongly. This change simplifies
the logic to only require that /dev/shm be _on_ tmpfs (which can be checked
trivially with statfs) rather than that it be a _mountpoint_ of tmpfs, since
there isn't a compelling reason to be that strict. We also now check for tmpfs
on whatever directory we ultimately use so that the user is better informed.

This change also moves the more standard TMPDIR environment variable check ahead
of the others.

Applies to 3.12.

Signed-off-by: Tristan Schmelcher <tschmelcher@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
10 years agoLinux 3.15-rc2
Linus Torvalds [Sun, 20 Apr 2014 18:08:50 +0000 (11:08 -0700)]
Linux 3.15-rc2

10 years agoMerge branch 'fixes' of git://git.infradead.org/users/vkoul/slave-dma
Linus Torvalds [Sun, 20 Apr 2014 17:35:31 +0000 (10:35 -0700)]
Merge branch 'fixes' of git://git.infradead.org/users/vkoul/slave-dma

Pull slave-dmaengine fixes from Vinod Koul:
 "Back from long weekend here in India and now the time to send fixes
  for slave dmaengine.
   - Dan's fix of sirf xlate code
   - Jean's fix for timberland
   - edma fixes by Sekhar for SG handling and Yuan for changing init
     call"

* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
  dma: fix eDMA driver as a subsys_initcall
  dmaengine: sirf: off by one in of_dma_sirfsoc_xlate()
  platform: Fix timberdale dependencies
  dma: edma: fix incorrect SG list handling

10 years agoMerge tag 'iommu-fixes-v3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Sun, 20 Apr 2014 17:33:49 +0000 (10:33 -0700)]
Merge tag 'iommu-fixes-v3.15-rc1' of git://git./linux/kernel/git/joro/iommu

Pull iommu fixes from Joerg Roedel:
 "Fixes for regressions:

   - fix wrong IOMMU enumeration causing some SCSI device drivers
     initialization failures
   - ARM-SMMU fixes for a panic condition and a wrong return value"

* tag 'iommu-fixes-v3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/arm-smmu: fix panic in arm_smmu_alloc_init_pte
  iommu/arm-smmu: Return 0 on unmap failure
  iommu/vt-d: fix bug in matching PCI devices with DRHD/RMRR descriptors
  iommu/vt-d: Fix get_domain_for_dev() handling of upstream PCIe bridges
  iommu/vt-d: fix memory leakage caused by commit ea8ea46

10 years agoMerge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Sun, 20 Apr 2014 17:32:33 +0000 (10:32 -0700)]
Merge branch 'perf-urgent-for-linus' of git://git./linux/kernel/git/tip/tip

Pull perf tooling fixes from Ingo Molnar:
 "Three small tooling fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf tools: Improve error reporting
  perf tools: Adjust symbols in VDSO
  perf kvm: Fix 'Min time' counting in report command

10 years agoMerge tag 'perf-urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git...
Ingo Molnar [Sun, 20 Apr 2014 07:53:55 +0000 (09:53 +0200)]
Merge tag 'perf-urgent-for-mingo' of git://git./linux/kernel/git/jolsa/perf into perf/urgent

Pull perf/urgent fixes from Jiri Olsa:

User visible changes:

  * Adjust symbols in VDSO to properly resolve its function names (Vladimir Nikulichev)

  * Improve error reporting for record session failure (Adrien BAK)

  * Fix 'Min time' counting in report command (Alexander Yarygin)

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agoperf tools: Improve error reporting
Adrien BAK [Fri, 18 Apr 2014 02:00:43 +0000 (11:00 +0900)]
perf tools: Improve error reporting

In the current version, when using perf record, if something goes
wrong in tools/perf/builtin-record.c:375
  session = perf_session__new(file, false, NULL);

The error message:
"Not enough memory for reading per file header"

is issued. This error message seems to be outdated and is not very
helpful. This patch proposes to replace this error message by
"Perf session creation failed"

I believe this issue has been brought to lkml:
https://lkml.org/lkml/2014/2/24/458
although this patch only tackles a (small) part of the issue.

Additionnaly, this patch improves error reporting in
tools/perf/util/data.c open_file_write.

Currently, if the call to open fails, the user is unaware of it.
This patch logs the error, before returning the error code to
the caller.

Reported-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Adrien BAK <adrien.bak@metascale.org>
Link: http://lkml.kernel.org/r/1397786443.3093.4.camel@beast
[ Reorganize the changelog into paragraphs ]
[ Added empty line after fd declaration in open_file_write ]
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
10 years agoperf tools: Adjust symbols in VDSO
Vladimir Nikulichev [Thu, 17 Apr 2014 15:27:01 +0000 (08:27 -0700)]
perf tools: Adjust symbols in VDSO

pert-report doesn't resolve function names in VDSO:

$ perf report --stdio -g flat,0.0,15,callee --sort pid
...
            8.76%
               0x7fff6b1fe861
               __gettimeofday
               ACE_OS::gettimeofday()
...

In this case symbol values should be adjusted the same way as for executables,
relocatable objects and prelinked libraries.

After fix:

$ perf report --stdio -g flat,0.0,15,callee --sort pid
...
            8.76%
               __vdso_gettimeofday
               __gettimeofday
               ACE_OS::gettimeofday()

Signed-off-by: Vladimir Nikulichev <nvs@tbricks.com>
Tested-by: Namhyung Kim <namhyung@kernel.org>
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Link: http://lkml.kernel.org/r/969812.163009436-sendEmail@nvs
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
10 years agoperf kvm: Fix 'Min time' counting in report command
Alexander Yarygin [Wed, 9 Apr 2014 14:21:59 +0000 (16:21 +0200)]
perf kvm: Fix 'Min time' counting in report command

Every event in the perf-kvm has a 'stats' structure, which contains
max/min/average/etc times of handling this event.
The problem is that the 'perf-kvm stat report' command always shows
that 'min time' is 0us for every event. Example:

 # perf kvm stat report

 Analyze events for all VCPUs:

    VM-EXIT    Samples  Samples%     Time%   Min Time   Max Time Avg time
  [..]
  0xB2 MSCH         12     0.07%     0.00%        0us        8us 7.31us ( +-   2.11% )
  0xB2 CHSC         12     0.07%     0.00%        0us       18us 9.39us ( +-   9.49% )
  0xB2 STPX          8     0.05%     0.00%        0us        2us 1.88us ( +-   7.18% )
  0xB2 STSI          7     0.04%     0.00%        0us       44us 16.49us ( +-  38.20% )
  [..]

This happens because the 'stats' structure is not initialized and
stats->min equals to 0. Lets initialize the structure for every
event after its allocation using init_stats() function. This initializes
stats->min to -1 and makes 'Min time' statistics counting work:

 # perf kvm stat report

 Analyze events for all VCPUs:

    VM-EXIT    Samples  Samples%     Time%   Min Time   Max Time Avg time
  [..]
  0xB2 MSCH         12     0.07%     0.00%        6us        8us 7.31us ( +-   2.11% )
  0xB2 CHSC         12     0.07%     0.00%        7us       18us 9.39us ( +-   9.49% )
  0xB2 STPX          8     0.05%     0.00%        1us        2us 1.88us ( +-   7.18% )
  0xB2 STSI          7     0.04%     0.00%        1us       44us 16.49us ( +-  38.20% )
  [..]

Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Link: http://lkml.kernel.org/r/1397053319-2130-3-git-send-email-borntraeger@de.ibm.com
[ Fixing the perf examples changelog output ]
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
10 years agoext4: disable COLLAPSE_RANGE for bigalloc
Namjae Jeon [Sat, 19 Apr 2014 20:38:21 +0000 (16:38 -0400)]
ext4: disable COLLAPSE_RANGE for bigalloc

Once COLLAPSE RANGE is be disable for ext4 with bigalloc feature till finding
root-cause of problem. It will be enable with fixing that regression of
xfstest(generic 075 and 091) again.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
10 years agoext4: fix COLLAPSE_RANGE failure with 1KB block size
Namjae Jeon [Sat, 19 Apr 2014 20:37:31 +0000 (16:37 -0400)]
ext4: fix COLLAPSE_RANGE failure with 1KB block size

When formatting with 1KB or 2KB(not aligned with PAGE SIZE) block
size, xfstests generic/075 and 091 are failing. The offset supplied to
function truncate_pagecache_range is block size aligned. In this
function start offset is re-aligned to PAGE_SIZE by rounding_up to the
next page boundary.  Due to this rounding up, old data remains in the
page cache when blocksize is less than page size and start offset is
not aligned with page size.  In case of collapse range, we need to
align start offset to page size boundary by doing a round down
operation instead of round up.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
10 years agocoredump: fix va_list corruption
Eric Dumazet [Sat, 19 Apr 2014 17:15:07 +0000 (10:15 -0700)]
coredump: fix va_list corruption

A va_list needs to be copied in case it needs to be used twice.

Thanks to Hugh for debugging this issue, leading to various panics.

Tested:

  lpq84:~# echo "|/foobar12345 %h %h %h %h %h %h %h %h %h %h %h %h %h %h %h %h %h %h %h %h" >/proc/sys/kernel/core_pattern

'produce_core' is simply : main() { *(int *)0 = 1;}

  lpq84:~# ./produce_core
  Segmentation fault (core dumped)
  lpq84:~# dmesg | tail -1
  [  614.352947] Core dump to |/foobar12345 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 (null) pipe failed

Notice the last argument was replaced by a NULL (we were lucky enough to
not crash, but do not try this on your production machine !)

After fix :

  lpq83:~# echo "|/foobar12345 %h %h %h %h %h %h %h %h %h %h %h %h %h %h %h %h %h %h %h %h" >/proc/sys/kernel/core_pattern
  lpq83:~# ./produce_core
  Segmentation fault
  lpq83:~# dmesg | tail -1
  [  740.800441] Core dump to |/foobar12345 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 pipe failed

Fixes: 5fe9d8ca21cc ("coredump: cn_vprintf() has no reason to call vsnprintf() twice")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Diagnosed-by: Hugh Dickins <hughd@google.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@vger.kernel.org # 3.11+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
10 years agoMerge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Sat, 19 Apr 2014 17:41:43 +0000 (10:41 -0700)]
Merge branch 'x86-urgent-for-linus' of git://git./linux/kernel/git/tip/tip

Pull x86 fix from Ingo Molnar:
 "This fixes the preemption-count imbalance crash reported by Owen
  Kibel"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mce: Fix CMCI preemption bugs

10 years agoMerge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Sat, 19 Apr 2014 17:40:51 +0000 (10:40 -0700)]
Merge branch 'sched-urgent-for-linus' of git://git./linux/kernel/git/tip/tip

Pull scheduler fixes from Ingo Molnar:
 "Two fixes:

   - a SCHED_DEADLINE task selection fix
   - a sched/numa related lockdep splat fix"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Check for stop task appearance when balancing happens
  sched/numa: Fix task_numa_free() lockdep splat

10 years agoMerge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Sat, 19 Apr 2014 17:40:11 +0000 (10:40 -0700)]
Merge branch 'perf-urgent-for-linus' of git://git./linux/kernel/git/tip/tip

Pull perf fixes from Ingo Molnar:
 "Two kernel side fixes:

   - an Intel uncore PMU driver potential crash fix
   - a kprobes/perf-call-graph interaction fix"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel: Use rdmsrl_safe() when initializing RAPL PMU
  kprobes/x86: Fix page-fault handling logic

10 years agoMerge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux
Linus Torvalds [Sat, 19 Apr 2014 17:35:30 +0000 (10:35 -0700)]
Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux

Pull drm fixes from Dave Airlie:
 "Unfortunately this contains no easter eggs, its a bit larger than I'd
  like, but I included a patch that just moves code from one file to
  another and I'd like to avoid merge conflicts with that later, so it
  makes it seem worse than it is,

  Otherwise:
   - radeon: fixes to use new microcode to stabilise some cards, use
     some common displayport code, some runtime pm fixes, pll regression
     fixes
   - i915: fix for some context oopses, a warn in a used path, backlight
     fixes
   - nouveau: regression fix
   - omap: a bunch of fixes"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (51 commits)
  drm: bochs: drop unused struct fields
  drm: bochs: add power management support
  drm: cirrus: add power management support
  drm: Split out drm_probe_helper.c from drm_crtc_helper.c
  drm/plane-helper: Don't fake-implement primary plane disabling
  drm/ast: fix value check in cbr_scan2
  drm/nouveau/bios: fix a bit shift error introduced by 457e77b
  drm/radeon/ci: make sure mc ucode is loaded before checking the size
  drm/radeon/si: make sure mc ucode is loaded before checking the size
  drm/radeon: improve PLL params if we don't match exactly v2
  drm/radeon: memory leak on bo reservation failure. v2
  drm/radeon: fix VCE fence command
  drm/radeon: re-enable mclk dpm on R7 260X asics
  drm/radeon: add support for newer mc ucode on CI (v2)
  drm/radeon: add support for newer mc ucode on SI (v2)
  drm/radeon: apply more strict limits for PLL params v2
  drm/radeon: update CI DPM powertune settings
  drm/radeon: fix runpm handling on APUs (v4)
  drm/radeon: disable mclk dpm on R7 260X
  drm/tegra: Remove gratuitous pad field
  ...

10 years agoMerge branch 'drm-next-3.15-wip' of git://people.freedesktop.org/~deathsimple/linux...
Dave Airlie [Sat, 19 Apr 2014 01:16:02 +0000 (11:16 +1000)]
Merge branch 'drm-next-3.15-wip' of git://people.freedesktop.org/~deathsimple/linux into drm-next

Some i2c fixes over DisplayPort.

* 'drm-next-3.15-wip' of git://people.freedesktop.org/~deathsimple/linux:
  drm/radeon: Improve vramlimit module param documentation
  drm/radeon: fix audio pin counts for DCE6+ (v2)
  drm/radeon/dp: switch to the common i2c over aux code
  drm/dp/i2c: Update comments about common i2c over dp assumptions (v3)
  drm/dp/i2c: send bare addresses to properly reset i2c connections (v4)
  drm/radeon/dp: handle zero sized i2c over aux transactions (v2)
  drm/i915: support address only i2c-over-aux transactions
  drm/tegra: dp: Support address-only I2C-over-AUX transactions

10 years agoMerge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Linus Torvalds [Sat, 19 Apr 2014 00:53:46 +0000 (17:53 -0700)]
Merge git://git./linux/kernel/git/davem/net

Pull more networking fixes from David Miller:

 1) Fix mlx4_en_netpoll implementation, it needs to schedule a NAPI
    context, not synchronize it.  From Chris Mason.

 2) Ipv4 flow input interface should never be zero, it should be
    LOOPBACK_IFINDEX instead.  From Cong Wang and Julian Anastasov.

 3) Properly configure MAC to PHY connection in mvneta devices, from
    Thomas Petazzoni.

 4) sys_recv should use SYSCALL_DEFINE.  From Jan Glauber.

 5) Tunnel driver ioctls do not use the correct namespace, fix from
    Nicolas Dichtel.

 6) Fix memory leak on seccomp filter attach, from Kees Cook.

 7) Fix lockdep warning for nested vlans, from Ding Tianhong.

 8) Crashes can happen in SCTP due to how the auth_enable value is
    managed, fix from Vlad Yasevich.

 9) Wireless fixes from John W Linville and co.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (45 commits)
  net: sctp: cache auth_enable per endpoint
  tg3: update rx_jumbo_pending ring param only when jumbo frames are enabled
  vlan: Fix lockdep warning when vlan dev handle notification
  seccomp: fix memory leak on filter attach
  isdn: icn: buffer overflow in icn_command()
  ip6_tunnel: use the right netns in ioctl handler
  sit: use the right netns in ioctl handler
  ip_tunnel: use the right netns in ioctl handler
  net: use SYSCALL_DEFINEx for sys_recv
  net: mdio-gpio: Add support for separate MDI and MDO gpio pins
  net: mdio-gpio: Add support for active low gpio pins
  net: mdio-gpio: Use devm_ functions where possible
  ipv4, route: pass 0 instead of LOOPBACK_IFINDEX to fib_validate_source()
  ipv4, fib: pass LOOPBACK_IFINDEX instead of 0 to flowi4_iif
  mlx4_en: don't use napi_synchronize inside mlx4_en_netpoll
  net: mvneta: properly configure the MAC <-> PHY connection in all situations
  net: phy: add minimal support for QSGMII PHY
  sfc:On MCDI timeout, issue an FLR (and mark MCDI to fail-fast)
  mwifiex: fix hung task on command timeout
  mwifiex: process event before command response
  ...

10 years agoMerge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6
Linus Torvalds [Sat, 19 Apr 2014 00:52:39 +0000 (17:52 -0700)]
Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:
 "A set of 5 small cifs fixes"

* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
  cif: fix dead code
  cifs: fix error handling cifs_user_readv
  fs: cifs: remove unused variable.
  Return correct error on query of xattr on file with empty xattrs
  cifs: Wait for writebacks to complete before attempting write.

10 years agoMerge tag 'char-misc-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregk...
Linus Torvalds [Sat, 19 Apr 2014 00:02:35 +0000 (17:02 -0700)]
Merge tag 'char-misc-3.15-rc2' of git://git./linux/kernel/git/gregkh/char-misc

Pull char/misc driver fixes from Greg KH:
 "Here are a few driver fixes for char/misc drivers that resolve
  reported issues.

  All have been in linux-next successfully for a few days"

* tag 'char-misc-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  Drivers: hv: vmbus: Negotiate version 3.0 when running on ws2012r2 hosts
  Tools: hv: Handle the case when the target file exists correctly
  vme_tsi148: Utilize to_pci_dev() macro
  vme_tsi148: Fix PCI address mapping assumption
  vme_tsi148: Fix typo in tsi148_slave_get()
  w1: avoid recursive device_add
  w1: fix netlink refcnt leak on error path
  misc: Grammar s/addition/additional/
  drivers: mcb: fix memory leak in chameleon_parse_cells() error path
  mei: ignore client writing state during cb completion
  mei: me: do not load the driver if the FW doesn't support MEI interface
  GenWQE: Increase driver version number
  GenWQE: Fix multithreading problems
  GenWQE: Ensure rc is not returning an uninitialized value
  GenWQE: Add wmb before DDCB is started
  GenWQE: Enable access to VPD flash area

10 years agoMerge tag 'driver-core-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Fri, 18 Apr 2014 23:59:52 +0000 (16:59 -0700)]
Merge tag 'driver-core-3.15-rc2' of git://git./linux/kernel/git/gregkh/driver-core

Pull driver core fixes from Greg KH:
 "Here are some driver core fixes for 3.15-rc2.  Also in here are some
  documentation updates, as well as an API removal that had to wait for
  after -rc1 due to the cleanups coming into you from multiple developer
  trees (this one and the PPC tree.)

  All have been in linux next successfully"

* tag 'driver-core-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  drivers/base/dd.c incorrect pr_debug() parameters
  Documentation: Update stable address in Chinese and Japanese translations
  topology: Fix compilation warning when not in SMP
  Chinese: add translation of io_ordering.txt
  stable_kernel_rules: spelling/word usage
  sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()
  kernfs: protect lazy kernfs_iattrs allocation with mutex
  fs: Don't return 0 from get_anon_bdev

10 years agoMerge tag 'staging-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh...
Linus Torvalds [Fri, 18 Apr 2014 23:58:47 +0000 (16:58 -0700)]
Merge tag 'staging-3.15-rc2' of git://git./linux/kernel/git/gregkh/staging

Pull staging driver fixes from Greg KH:
 "Here are a few staging driver fixes for issues that have been reported
  for 3.15-rc2.

  Also dominating the diffstat for the pull request is the removal of
  the rtl8187se driver.  It's no longer needed in staging as a "real"
  driver for this hardware is now merged in the tree in the "correct"
  location in drivers/net/

  All of these patches have been tested in linux-next"

* tag 'staging-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: r8188eu: Fix case where ethtype was never obtained and always be checked against 0
  staging: r8712u: Fix case where ethtype was never obtained and always be checked against 0
  staging: r8188eu: Calling rtw_get_stainfo() with a NULL sta_addr will return NULL
  staging: comedi: fix circular locking dependency in comedi_mmap()
  staging: r8723au: Add missing initialization of change_inx in sort algorithm
  Staging: unisys: use after free in list_for_each()
  staging: unisys: use after free in error messages
  staging: speakup: fix misuse of kstrtol() in handle_goto()
  staging: goldfish: Call free_irq in error path
  staging: delete rtl8187se wireless driver
  staging: rtl8723au: Fix buffer overflow in rtw_get_wfd_ie()
  staging: gs_fpgaboot: remove __TIMESTAMP__ macro
  staging: vme: fix memory leak in vme_user_probe()
  staging: fpgaboot: clean up Makefile
  staging/usbip: fix store_attach() sscanf return value check
  staging/usbip: userspace - fix usbipd SIGSEGV from refresh_exported_devices()
  staging: rtl8188eu: remove spaces, correct counts to unbreak P2P ioctls
  staging/rtl8821ae: Fix OOM handling in _rtl_init_deferred_work()

10 years agoMerge tag 'tty-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Linus Torvalds [Fri, 18 Apr 2014 23:57:53 +0000 (16:57 -0700)]
Merge tag 'tty-3.15-rc2' of git://git./linux/kernel/git/gregkh/tty

Pull tty/serial driver fixes from Greg KH:
 "Here are a number of small tty/serial driver fixes for 3.15-rc2.  Also
  in here are some Documentation file removals for drivers that we
  removed a long time ago, no need to keep it around any longer.

  All of these have been in linux-next for a bit"

* tag 'tty-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  Revert "serial: 8250, disable "too much work" messages"
  serial: amba-pl011: fix regression, causing an Oops on rmmod
  tty: Fix help text of SYNCLINK_CS
  tty: fix memleak in alloc_pid
  ttyprintk: Allow built as a module
  ttyprintk: Fix wrong tty_unregister_driver() call in the error path
  serial: 8250, disable "too much work" messages
  Documentation/serial: Delete obsolete driver documentation
  serial: omap: Fix missing pm_runtime_resume handling by simplifying code
  serial_core: Fix pm imbalance on unbind
  serial: pl011: change Rx burst size to half of trigger level
  serial: timberdale: Depend on X86_32
  serial: st-asc: Fix SysRq char handling
  Revert "serial: clps711x: Give a chance to perform useful tasks during wait loop"
  serial_core: Fix conditional start_tx on ring buffer not empty
  serial: efm32: use $vendor,$device scheme for compatible string
  serial: omap: free the wakeup settings in remove

10 years agoMerge tag 'usb-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Linus Torvalds [Fri, 18 Apr 2014 23:57:00 +0000 (16:57 -0700)]
Merge tag 'usb-3.15-rc2' of git://git./linux/kernel/git/gregkh/usb

Pull USB fixes from Greg KH:
 "Here are a number of tiny USB fixes and new device ids for 3.15-rc2.
  Nothing major, just issues some people have reported.

  All of these have been in linux-next"

* tag 'usb-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  uas: fix deadlocky memory allocations
  uas: fix error handling during scsi_scan()
  uas: fix GFP_NOIO under spinlock
  uwb: adds missing error handling
  USB: cdc-acm: Remove Motorola/Telit H24 serial interfaces from ACM driver
  USB: ohci-jz4740: FEAT_POWER is a port feature, not a hub feature
  USB: ohci-jz4740: Fix uninitialized variable warning
  USB: EHCI: tegra: set txfill_tuning
  usb: ehci-platform: Return immediately from suspend if ehci_suspend fails
  usb: ehci-exynos: Return immediately from suspend if ehci_suspend fails
  USB: fix crash during hotplug of PCI USB controller card
  USB: cdc-acm: fix double usb_autopm_put_interface() in acm_port_activate()
  usb: usb-common: fix typo for usb_state_string
  USB: usb_wwan: fix handling of missing bulk endpoints
  USB: pl2303: add ids for Hewlett-Packard HP POS pole displays
  USB: cp210x: Add 8281 (Nanotec Plug & Drive)
  usb: option driver, add support for Telit UE910v2
  Revert "USB: serial: add usbid for dell wwan card to sierra.c"
  USB: serial: ftdi_sio: add id for Brainboxes serial cards

10 years agoMerge branch 'akpm' (incoming from Andrew)
Linus Torvalds [Fri, 18 Apr 2014 23:40:31 +0000 (16:40 -0700)]
Merge branch 'akpm' (incoming from Andrew)

Merge misc fixes from Andrew Morton:
 "13 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  thp: close race between split and zap huge pages
  mm: fix new kernel-doc warning in filemap.c
  mm: fix CONFIG_DEBUG_VM_RB description
  mm: use paravirt friendly ops for NUMA hinting ptes
  mips: export flush_icache_range
  mm/hugetlb.c: add cond_resched_lock() in return_unused_surplus_pages()
  wait: explain the shadowing and type inconsistencies
  Shiraz has moved
  Documentation/vm/numa_memory_policy.txt: fix wrong document in numa_memory_policy.txt
  powerpc/mm: fix ".__node_distance" undefined
  kernel/watchdog.c:touch_softlockup_watchdog(): use raw_cpu_write()
  init/Kconfig: move the trusted keyring config option to general setup
  vmscan: reclaim_clean_pages_from_list() must use mod_zone_page_state()

10 years agothp: close race between split and zap huge pages
Kirill A. Shutemov [Fri, 18 Apr 2014 22:07:25 +0000 (15:07 -0700)]
thp: close race between split and zap huge pages

Sasha Levin has reported two THP BUGs[1][2].  I believe both of them
have the same root cause.  Let's look to them one by one.

The first bug[1] is "kernel BUG at mm/huge_memory.c:1829!".  It's
BUG_ON(mapcount != page_mapcount(page)) in __split_huge_page().  From my
testing I see that page_mapcount() is higher than mapcount here.

I think it happens due to race between zap_huge_pmd() and
page_check_address_pmd().  page_check_address_pmd() misses PMD which is
under zap:

CPU0 CPU1
zap_huge_pmd()
  pmdp_get_and_clear()
__split_huge_page()
  anon_vma_interval_tree_foreach()
    __split_huge_page_splitting()
      page_check_address_pmd()
        mm_find_pmd()
  /*
   * We check if PMD present without taking ptl: no
   * serialization against zap_huge_pmd(). We miss this PMD,
   * it's not accounted to 'mapcount' in __split_huge_page().
   */
  pmd_present(pmd) == 0

  BUG_ON(mapcount != page_mapcount(page)) // CRASH!!!

  page_remove_rmap(page)
    atomic_add_negative(-1, &page->_mapcount)

The second bug[2] is "kernel BUG at mm/huge_memory.c:1371!".
It's VM_BUG_ON_PAGE(!PageHead(page), page) in zap_huge_pmd().

This happens in similar way:

CPU0 CPU1
zap_huge_pmd()
  pmdp_get_and_clear()
  page_remove_rmap(page)
    atomic_add_negative(-1, &page->_mapcount)
__split_huge_page()
  anon_vma_interval_tree_foreach()
    __split_huge_page_splitting()
      page_check_address_pmd()
        mm_find_pmd()
  pmd_present(pmd) == 0 /* The same comment as above */
  /*
   * No crash this time since we already decremented page->_mapcount in
   * zap_huge_pmd().
   */
  BUG_ON(mapcount != page_mapcount(page))

  /*
   * We split the compound page here into small pages without
   * serialization against zap_huge_pmd()
   */
  __split_huge_page_refcount()
VM_BUG_ON_PAGE(!PageHead(page), page); // CRASH!!!

So my understanding the problem is pmd_present() check in mm_find_pmd()
without taking page table lock.

The bug was introduced by me commit with commit 117b0791ac42. Sorry for
that. :(

Let's open code mm_find_pmd() in page_check_address_pmd() and do the
check under page table lock.

Note that __page_check_address() does the same for PTE entires
if sync != 0.

I've stress tested split and zap code paths for 36+ hours by now and
don't see crashes with the patch applied. Before it took <20 min to
trigger the first bug and few hours for second one (if we ignore
first).

[1] https://lkml.kernel.org/g/<53440991.9090001@oracle.com>
[2] https://lkml.kernel.org/g/<5310C56C.60709@oracle.com>

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Bob Liu <lliubbo@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michel Lespinasse <walken@google.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org> [3.13+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
10 years agomm: fix new kernel-doc warning in filemap.c
Randy Dunlap [Fri, 18 Apr 2014 22:07:23 +0000 (15:07 -0700)]
mm: fix new kernel-doc warning in filemap.c

Fix new kernel-doc warning in mm/filemap.c:

  Warning(mm/filemap.c:2600): Excess function parameter 'ppos' description in '__generic_file_aio_write'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
10 years agomm: fix CONFIG_DEBUG_VM_RB description
Davidlohr Bueso [Fri, 18 Apr 2014 22:07:22 +0000 (15:07 -0700)]
mm: fix CONFIG_DEBUG_VM_RB description

This appears to be a copy/paste error.  Update the description to
reflect extra rbtree debug and checks for the config option instead of
duplicating CONFIG_DEBUG_VM.

Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
10 years agomm: use paravirt friendly ops for NUMA hinting ptes
Mel Gorman [Fri, 18 Apr 2014 22:07:21 +0000 (15:07 -0700)]
mm: use paravirt friendly ops for NUMA hinting ptes

David Vrabel identified a regression when using automatic NUMA balancing
under Xen whereby page table entries were getting corrupted due to the
use of native PTE operations.  Quoting him

Xen PV guest page tables require that their entries use machine
addresses if the preset bit (_PAGE_PRESENT) is set, and (for
successful migration) non-present PTEs must use pseudo-physical
addresses.  This is because on migration MFNs in present PTEs are
translated to PFNs (canonicalised) so they may be translated back
to the new MFN in the destination domain (uncanonicalised).

pte_mknonnuma(), pmd_mknonnuma(), pte_mknuma() and pmd_mknuma()
set and clear the _PAGE_PRESENT bit using pte_set_flags(),
pte_clear_flags(), etc.

In a Xen PV guest, these functions must translate MFNs to PFNs
when clearing _PAGE_PRESENT and translate PFNs to MFNs when setting
_PAGE_PRESENT.

His suggested fix converted p[te|md]_[set|clear]_flags to using
paravirt-friendly ops but this is overkill.  He suggested an alternative
of using p[te|md]_modify in the NUMA page table operations but this is
does more work than necessary and would require looking up a VMA for
protections.

This patch modifies the NUMA page table operations to use paravirt
friendly operations to set/clear the flags of interest.  Unfortunately
this will take a performance hit when updating the PTEs on
CONFIG_PARAVIRT but I do not see a way around it that does not break
Xen.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: David Vrabel <david.vrabel@citrix.com>
Tested-by: David Vrabel <david.vrabel@citrix.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steven Noonan <steven@uplinklabs.net>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
10 years agomips: export flush_icache_range
Kees Cook [Fri, 18 Apr 2014 22:07:19 +0000 (15:07 -0700)]
mips: export flush_icache_range

The lkdtm module performs tests against executable memory ranges, so it
needs to flush the icache for proper behaviors.  Other architectures
already export this, so do the same for MIPS.

[akpm@linux-foundation.org: relocate export sites]
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Cc: John Crispin <blogic@openwrt.org>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
10 years agomm/hugetlb.c: add cond_resched_lock() in return_unused_surplus_pages()
Mizuma, Masayoshi [Fri, 18 Apr 2014 22:07:18 +0000 (15:07 -0700)]
mm/hugetlb.c: add cond_resched_lock() in return_unused_surplus_pages()

soft lockup in freeing gigantic hugepage fixed in commit 55f67141a892 "mm:
hugetlb: fix softlockup when a large number of hugepages are freed." can
happen in return_unused_surplus_pages(), so let's fix it.

Signed-off-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
10 years agowait: explain the shadowing and type inconsistencies
Peter Zijlstra [Fri, 18 Apr 2014 22:07:17 +0000 (15:07 -0700)]
wait: explain the shadowing and type inconsistencies

Stick in a comment before someone else tries to fix the sparse warning
this generates.

Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-o2ro6f3vkxklni0bc8f7m68s@git.kernel.org
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
10 years agoShiraz has moved
Viresh Kumar [Fri, 18 Apr 2014 22:07:16 +0000 (15:07 -0700)]
Shiraz has moved

shiraz.hashim@st.com email-id doesn't exist anymore as he has left the
company.  Replace ST's id with shiraz.linux.kernel@gmail.com.

It also updates .mailmap file to fix address for 'git shortlog'.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Shiraz Hashim <shiraz.linux.kernel@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
10 years agoDocumentation/vm/numa_memory_policy.txt: fix wrong document in numa_memory_policy.txt
Tang Chen [Fri, 18 Apr 2014 22:07:15 +0000 (15:07 -0700)]
Documentation/vm/numa_memory_policy.txt: fix wrong document in numa_memory_policy.txt

In document numa_memory_policy.txt, the following examples for flag
MPOL_F_RELATIVE_NODES are incorrect.

For example, consider a task that is attached to a cpuset with
mems 2-5 that sets an Interleave policy over the same set with
MPOL_F_RELATIVE_NODES.  If the cpuset's mems change to 3-7, the
interleave now occurs over nodes 3,5-6.  If the cpuset's mems
then change to 0,2-3,5, then the interleave occurs over nodes
0,3,5.

According to the comment of the patch adding flag MPOL_F_RELATIVE_NODES,
the nodemasks the user specifies should be considered relative to the
current task's mems_allowed.

 (https://lkml.org/lkml/2008/2/29/428)

And according to numa_memory_policy.txt, if the user's nodemask includes
nodes that are outside the range of the new set of allowed nodes, then
the remap wraps around to the beginning of the nodemask and, if not
already set, sets the node in the mempolicy nodemask.

So in the example, if the user specifies 2-5, for a task whose
mems_allowed is 3-7, the nodemasks should be remapped the third, fourth,
fifth, sixth node in mems_allowed.  like the following:

mems_allowed:       3  4  5  6  7

relative index:     0  1  2  3  4
                    5

So the nodemasks should be remapped to 3,5-7, but not 3,5-6.

And for a task whose mems_allowed is 0,2-3,5, the nodemasks should be
remapped to 0,2-3,5, but not 0,3,5.

mems_allowed:       0  2  3  5

        relative index:     0  1  2  3
                            4  5

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
10 years agopowerpc/mm: fix ".__node_distance" undefined
Mike Qiu [Fri, 18 Apr 2014 22:07:14 +0000 (15:07 -0700)]
powerpc/mm: fix ".__node_distance" undefined

  CHK     include/config/kernel.release
  CHK     include/generated/uapi/linux/version.h
  CHK     include/generated/utsrelease.h
  ...
  Building modules, stage 2.
WARNING: 1 bad relocations
c0000000013d6a30 R_PPC64_ADDR64    uprobes_fetch_type_table
  WRAP    arch/powerpc/boot/zImage.pseries
  WRAP    arch/powerpc/boot/zImage.epapr
  MODPOST 1849 modules
ERROR: ".__node_distance" [drivers/block/nvme.ko] undefined!
make[1]: *** [__modpost] Error 1
make: *** [modules] Error 2
make: *** Waiting for unfinished jobs....

The reason is symbol "__node_distance" not been exported in powerpc.

Signed-off-by: Mike Qiu <qiudayu@linux.vnet.ibm.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Jesse Larrew <jlarrew@linux.vnet.ibm.com>
Cc: Robert Jennings <rcj@linux.vnet.ibm.com>
Cc: Alistair Popple <alistair@popple.id.au>
Cc: Mike Qiu <qiudayu@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
10 years agokernel/watchdog.c:touch_softlockup_watchdog(): use raw_cpu_write()
Andrew Morton [Fri, 18 Apr 2014 22:07:12 +0000 (15:07 -0700)]
kernel/watchdog.c:touch_softlockup_watchdog(): use raw_cpu_write()

Fix:

  BUG: using __this_cpu_write() in preemptible [00000000] code: systemd-udevd/497
  caller is __this_cpu_preempt_check+0x13/0x20
  CPU: 3 PID: 497 Comm: systemd-udevd Tainted: G        W     3.15.0-rc1 #9
  Hardware name: Hewlett-Packard HP EliteBook 8470p/179B, BIOS 68ICF Ver. F.02 04/27/2012
  Call Trace:
    check_preemption_disabled+0xe1/0xf0
    __this_cpu_preempt_check+0x13/0x20
    touch_nmi_watchdog+0x28/0x40

Reported-by: Luis Henriques <luis.henriques@canonical.com>
Tested-by: Luis Henriques <luis.henriques@canonical.com>
Cc: Eric Piel <eric.piel@tremplin-utc.net>
Cc: Robert Moore <robert.moore@intel.com>
Cc: Lv Zheng <lv.zheng@intel.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
10 years agoinit/Kconfig: move the trusted keyring config option to general setup
Peter Foley [Fri, 18 Apr 2014 22:07:11 +0000 (15:07 -0700)]
init/Kconfig: move the trusted keyring config option to general setup

The SYSTEM_TRUSTED_KEYRING config option is not in any menu, causing it
to show up in the toplevel of the kernel configuration.  Fix this by
moving it under the General Setup menu.

Signed-off-by: Peter Foley <pefoley2@pefoley.com>
Cc: David Howells <dhowells@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>
10 years agovmscan: reclaim_clean_pages_from_list() must use mod_zone_page_state()
Christoph Lameter [Fri, 18 Apr 2014 22:07:10 +0000 (15:07 -0700)]
vmscan: reclaim_clean_pages_from_list() must use mod_zone_page_state()

Seems to be called with preemption enabled.  Therefore it must use
mod_zone_page_state instead.

Signed-off-by: Christoph Lameter <cl@linux.com>
Reported-by: Grygorii Strashko <grygorii.strashko@ti.com>
Tested-by: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
10 years agonet: sctp: cache auth_enable per endpoint
Vlad Yasevich [Thu, 17 Apr 2014 15:26:50 +0000 (17:26 +0200)]
net: sctp: cache auth_enable per endpoint

Currently, it is possible to create an SCTP socket, then switch
auth_enable via sysctl setting to 1 and crash the system on connect:

Oops[#1]:
CPU: 0 PID: 0 Comm: swapper Not tainted 3.14.1-mipsgit-20140415 #1
task: ffffffff8056ce80 ti: ffffffff8055c000 task.ti: ffffffff8055c000
[...]
Call Trace:
[<ffffffff8043c4e8>] sctp_auth_asoc_set_default_hmac+0x68/0x80
[<ffffffff8042b300>] sctp_process_init+0x5e0/0x8a4
[<ffffffff8042188c>] sctp_sf_do_5_1B_init+0x234/0x34c
[<ffffffff804228c8>] sctp_do_sm+0xb4/0x1e8
[<ffffffff80425a08>] sctp_endpoint_bh_rcv+0x1c4/0x214
[<ffffffff8043af68>] sctp_rcv+0x588/0x630
[<ffffffff8043e8e8>] sctp6_rcv+0x10/0x24
[<ffffffff803acb50>] ip6_input+0x2c0/0x440
[<ffffffff8030fc00>] __netif_receive_skb_core+0x4a8/0x564
[<ffffffff80310650>] process_backlog+0xb4/0x18c
[<ffffffff80313cbc>] net_rx_action+0x12c/0x210
[<ffffffff80034254>] __do_softirq+0x17c/0x2ac
[<ffffffff800345e0>] irq_exit+0x54/0xb0
[<ffffffff800075a4>] ret_from_irq+0x0/0x4
[<ffffffff800090ec>] rm7k_wait_irqoff+0x24/0x48
[<ffffffff8005e388>] cpu_startup_entry+0xc0/0x148
[<ffffffff805a88b0>] start_kernel+0x37c/0x398
Code: dd0900b8  000330f8  0126302d <dcc6000050c0fff1  0047182a  a48306a0
03e00008  00000000
---[ end trace b530b0551467f2fd ]---
Kernel panic - not syncing: Fatal exception in interrupt

What happens while auth_enable=0 in that case is, that
ep->auth_hmacs is initialized to NULL in sctp_auth_init_hmacs()
when endpoint is being created.

After that point, if an admin switches over to auth_enable=1,
the machine can crash due to NULL pointer dereference during
reception of an INIT chunk. When we enter sctp_process_init()
via sctp_sf_do_5_1B_init() in order to respond to an INIT chunk,
the INIT verification succeeds and while we walk and process
all INIT params via sctp_process_param() we find that
net->sctp.auth_enable is set, therefore do not fall through,
but invoke sctp_auth_asoc_set_default_hmac() instead, and thus,
dereference what we have set to NULL during endpoint
initialization phase.

The fix is to make auth_enable immutable by caching its value
during endpoint initialization, so that its original value is
being carried along until destruction. The bug seems to originate
from the very first days.

Fix in joint work with Daniel Borkmann.

Reported-by: Joshua Kinard <kumba@gentoo.org>
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Tested-by: Joshua Kinard <kumba@gentoo.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
10 years agoMerge branch 'for-davem' of git://git.kernel.org/pub/scm/linux/kernel/git/linville...
David S. Miller [Fri, 18 Apr 2014 22:29:44 +0000 (18:29 -0400)]
Merge branch 'for-davem' of git://git./linux/kernel/git/linville/wireless

John W. Linville says:

====================
pull request: wireless 2014-04-17

Please pull this batch of fixes intended for the 3.15 stream...

For the mac80211 bits, Johannes says:

"We have a fix from Chun-Yeow to not look at management frame bitrates
that are typically really low, two fixes from Felix for AP_VLAN
interfaces, a fix from Ido to disable SMPS settings when a monitor
interface is enabled, a radar detection fix from Michał and a fix from
myself for a very old remain-on-channel bug."

For the iwlwifi bits, Emmanuel says:

"I have new device IDs and a new firmware API. These are the trivial
ones. The less trivial ones are Johannes's fix that delays the
enablement of an interrupt coalescing hardware until after association
- this fixes a few connection problems seen in the field. Eyal has a
bunch of rate control fixes. I decided to add these for 3.15 because
they fix some disconnection and packet loss scenarios which were
reported by the field. I also have a fix for a memory leak that
happens only with a very new NIC."

Along with those...

Amitkumar Karwar fixes a couple of problems relating to driver/firmware
interactions in mwifiex.

Christian Engelmayer avoids a couple of potential memory leaks in
the new rsi driver.

Eliad Peller provides a wl18xx mailbox alignment fix for problems
when using new firmware.

Frederic Danis adds a couple of missing debugging strings to the
cw1200 driver.

Geert Uytterhoeven adds a variable initialization inside of the
rsi driver.

Luciano Coelho patches the wlcore code to ignore dummy packet events
in PLT mode in order to work around a firmware bug.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
10 years agotg3: update rx_jumbo_pending ring param only when jumbo frames are enabled
Ivan Vecera [Thu, 17 Apr 2014 12:51:08 +0000 (14:51 +0200)]
tg3: update rx_jumbo_pending ring param only when jumbo frames are enabled

The patch fixes a problem with dropped jumbo frames after usage of
'ethtool -G ... rx'.

Scenario:
1. ip link set eth0 up
2. ethtool -G eth0 rx N # <- This zeroes rx-jumbo
3. ip link set mtu 9000 dev eth0

The ethtool command set rx_jumbo_pending to zero so any received jumbo
packets are dropped and you need to use 'ethtool -G eth0 rx-jumbo N'
to workaround the issue.
The patch changes the logic so rx_jumbo_pending value is changed only if
jumbo frames are enabled (MTU > 1500).

Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Acked-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
10 years agovlan: Fix lockdep warning when vlan dev handle notification
dingtianhong [Thu, 17 Apr 2014 10:40:36 +0000 (18:40 +0800)]
vlan: Fix lockdep warning when vlan dev handle notification

When I open the LOCKDEP config and run these steps:

modprobe 8021q
vconfig add eth2 20
vconfig add eth2.20 30
ifconfig eth2 xx.xx.xx.xx

then the Call Trace happened:

[32524.386288] =============================================
[32524.386293] [ INFO: possible recursive locking detected ]
[32524.386298] 3.14.0-rc2-0.7-default+ #35 Tainted: G           O
[32524.386302] ---------------------------------------------
[32524.386306] ifconfig/3103 is trying to acquire lock:
[32524.386310]  (&vlan_netdev_addr_lock_key/1){+.....}, at: [<ffffffff814275f4>] dev_mc_sync+0x64/0xb0
[32524.386326]
[32524.386326] but task is already holding lock:
[32524.386330]  (&vlan_netdev_addr_lock_key/1){+.....}, at: [<ffffffff8141af83>] dev_set_rx_mode+0x23/0x40
[32524.386341]
[32524.386341] other info that might help us debug this:
[32524.386345]  Possible unsafe locking scenario:
[32524.386345]
[32524.386350]        CPU0
[32524.386352]        ----
[32524.386354]   lock(&vlan_netdev_addr_lock_key/1);
[32524.386359]   lock(&vlan_netdev_addr_lock_key/1);
[32524.386364]
[32524.386364]  *** DEADLOCK ***
[32524.386364]
[32524.386368]  May be due to missing lock nesting notation
[32524.386368]
[32524.386373] 2 locks held by ifconfig/3103:
[32524.386376]  #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff81431d42>] rtnl_lock+0x12/0x20
[32524.386387]  #1:  (&vlan_netdev_addr_lock_key/1){+.....}, at: [<ffffffff8141af83>] dev_set_rx_mode+0x23/0x40
[32524.386398]
[32524.386398] stack backtrace:
[32524.386403] CPU: 1 PID: 3103 Comm: ifconfig Tainted: G           O 3.14.0-rc2-0.7-default+ #35
[32524.386409] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[32524.386414]  ffffffff81ffae40 ffff8800d9625ae8 ffffffff814f68a2 ffff8800d9625bc8
[32524.386421]  ffffffff810a35fb ffff8800d8a8d9d0 00000000d9625b28 ffff8800d8a8e5d0
[32524.386428]  000003cc00000000 0000000000000002 ffff8800d8a8e5f8 0000000000000000
[32524.386435] Call Trace:
[32524.386441]  [<ffffffff814f68a2>] dump_stack+0x6a/0x78
[32524.386448]  [<ffffffff810a35fb>] __lock_acquire+0x7ab/0x1940
[32524.386454]  [<ffffffff810a323a>] ? __lock_acquire+0x3ea/0x1940
[32524.386459]  [<ffffffff810a4874>] lock_acquire+0xe4/0x110
[32524.386464]  [<ffffffff814275f4>] ? dev_mc_sync+0x64/0xb0
[32524.386471]  [<ffffffff814fc07a>] _raw_spin_lock_nested+0x2a/0x40
[32524.386476]  [<ffffffff814275f4>] ? dev_mc_sync+0x64/0xb0
[32524.386481]  [<ffffffff814275f4>] dev_mc_sync+0x64/0xb0
[32524.386489]  [<ffffffffa0500cab>] vlan_dev_set_rx_mode+0x2b/0x50 [8021q]
[32524.386495]  [<ffffffff8141addf>] __dev_set_rx_mode+0x5f/0xb0
[32524.386500]  [<ffffffff8141af8b>] dev_set_rx_mode+0x2b/0x40
[32524.386506]  [<ffffffff8141b3cf>] __dev_open+0xef/0x150
[32524.386511]  [<ffffffff8141b177>] __dev_change_flags+0xa7/0x190
[32524.386516]  [<ffffffff8141b292>] dev_change_flags+0x32/0x80
[32524.386524]  [<ffffffff8149ca56>] devinet_ioctl+0x7d6/0x830
[32524.386532]  [<ffffffff81437b0b>] ? dev_ioctl+0x34b/0x660
[32524.386540]  [<ffffffff814a05b0>] inet_ioctl+0x80/0xa0
[32524.386550]  [<ffffffff8140199d>] sock_do_ioctl+0x2d/0x60
[32524.386558]  [<ffffffff81401a52>] sock_ioctl+0x82/0x2a0
[32524.386568]  [<ffffffff811a7123>] do_vfs_ioctl+0x93/0x590
[32524.386578]  [<ffffffff811b2705>] ? rcu_read_lock_held+0x45/0x50
[32524.386586]  [<ffffffff811b39e5>] ? __fget_light+0x105/0x110
[32524.386594]  [<ffffffff811a76b1>] SyS_ioctl+0x91/0xb0
[32524.386604]  [<ffffffff815057e2>] system_call_fastpath+0x16/0x1b

========================================================================

The reason is that all of the addr_lock_key for vlan dev have the same class,
so if we change the status for vlan dev, the vlan dev and its real dev will
hold the same class of addr_lock_key together, so the warning happened.

we should distinguish the lock depth for vlan dev and its real dev.

v1->v2: Convert the vlan_netdev_addr_lock_key to an array of eight elements, which
could support to add 8 vlan id on a same vlan dev, I think it is enough for current
scene, because a netdev's name is limited to IFNAMSIZ which could not hold 8 vlan id,
and the vlan dev would not meet the same class key with its real dev.

The new function vlan_dev_get_lockdep_subkey() will return the subkey and make the vlan
dev could get a suitable class key.

v2->v3: According David's suggestion, I use the subclass to distinguish the lock key for vlan dev
and its real dev, but it make no sense, because the difference for subclass in the
lock_class_key doesn't mean that the difference class for lock_key, so I use lock_depth
to distinguish the different depth for every vlan dev, the same depth of the vlan dev
could have the same lock_class_key, I import the MAX_LOCK_DEPTH from the include/linux/sched.h,
I think it is enough here, the lockdep should never exceed that value.

v3->v4: Add a huge array of locking keys will waste static kernel memory and is not a appropriate method,
we could use _nested() variants to fix the problem, calculate the depth for every vlan dev,
and use the depth as the subclass for addr_lock_key.

Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
10 years agoMerge tag 'rdma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland...
Linus Torvalds [Fri, 18 Apr 2014 20:49:42 +0000 (13:49 -0700)]
Merge tag 'rdma-for-linus' of git://git./linux/kernel/git/roland/infiniband

Pull infiniband/rdma updates from Roland Dreier:

 - mostly cxgb4 fixes unblocked by the merge of some prerequisites via
   the net tree

 - drop deprecated MSI-X API use.

 - a couple other miscellaneous things.

* tag 'rdma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
  RDMA/cxgb4: Fix over-dereference when terminating
  RDMA/cxgb4: Use uninitialized_var()
  RDMA/cxgb4: Add missing debug stats
  RDMA/cxgb4: Initialize reserved fields in a FW work request
  RDMA/cxgb4: Use pr_warn_ratelimited
  RDMA/cxgb4: Max fastreg depth depends on DSGL support
  RDMA/cxgb4: SQ flush fix
  RDMA/cxgb4: rmb() after reading valid gen bit
  RDMA/cxgb4: Endpoint timeout fixes
  RDMA/cxgb4: Use the BAR2/WC path for kernel QPs and T5 devices
  IB/mlx5: Add block multicast loopback support
  IB/mthca: Use pci_enable_msix_exact() instead of pci_enable_msix()
  IB/qib: Use pci_enable_msix_range() instead of pci_enable_msix()

10 years agoARC: Delete stale barrier.h
Vineet Gupta [Fri, 18 Apr 2014 08:08:34 +0000 (13:38 +0530)]
ARC: Delete stale barrier.h

Commit 93ea02bb8435 ("arch: Clean up asm/barrier.h implementations")
wired generic barrier.h for ARC, but failed to delete the existing file.

In 3.15, due to rcupdate.h updates, this causes a build breakage on ARC:

      CC      arch/arc/kernel/asm-offsets.s
    In file included from include/linux/sched.h:45:0,
                     from arch/arc/kernel/asm-offsets.c:9:
    include/linux/rculist.h: In function __list_add_rcu:
    include/linux/rculist.h:54:2: error: implicit declaration of function smp_store_release [-Werror=implicit-function-declaration]
      rcu_assign_pointer(list_next_rcu(prev), new);
      ^

Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
10 years agoMerge tag 'pci-v3.15-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaa...
Linus Torvalds [Fri, 18 Apr 2014 17:56:27 +0000 (10:56 -0700)]
Merge tag 'pci-v3.15-fixes-1' of git://git./linux/kernel/git/helgaas/pci

Pull PCI updates from Bjorn Helgaas:
 "These are fixes for a powerpc NULL pointer dereference, an OF
  interrupt mapping issue on some of the new host bridges, and a
  DesignWare iATU issue.

  Host bridge drivers
   - Fix OF interrupt mapping for DesignWare, R-Car, Tegra (Lucas Stach)
   - Fix DesignWare iATU programming (Mohit Kumar)

  Miscellaneous
    - Fix powerpc NULL dereference from list_for_each_entry() update (Mike Qiu)"

* tag 'pci-v3.15-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: tegra: Use new OF interrupt mapping when possible
  PCI: rcar: Use new OF interrupt mapping when possible
  PCI: designware: Use new OF interrupt mapping when possible
  PCI: designware: Fix iATU programming for cfg1, io and mem viewport
  PCI: designware: Fix comment for setting number of lanes
  powerpc/PCI: Fix NULL dereference in sys_pciconfig_iobase() list traversal

10 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
Linus Torvalds [Fri, 18 Apr 2014 17:31:34 +0000 (10:31 -0700)]
Merge branch 'for-linus' of git://git./linux/kernel/git/jikos/hid

Pull HID fixes from Jiri Kosina:
 - fix for merge window mismerge in hid-sony, from Frank Praznik
 - fix for Surface Type/Touch Cover 2 device, from Benjamin Tissoires
 - quirk for ThinkPad Helix sensor hub from Stephen Chandler Paul

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: core: do not scan constant input report
  Revert "HID: microsoft: Add ID's for Surface Type/Touch Cover 2"
  HID: sensor-hub: add sensor hub quirk for ThinkPad Helix
  HID: sony: Fix cancel_work_sync mismerge

10 years agoMerge tag 'sound-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai...
Linus Torvalds [Fri, 18 Apr 2014 17:28:27 +0000 (10:28 -0700)]
Merge tag 'sound-3.15-rc2' of git://git./linux/kernel/git/tiwai/sound

Pull sound fixes from Takashi Iwai:
 "Just a copule of HD-audio device/codec-specific quirks, and a trivial
  replacement of udelay() with mdelay() in the old es18xx driver code.
  All should be safe to apply"

* tag 'sound-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda/realtek - Add headset Mic support for Dell machine
  ALSA: hda - add headset mic detect quirk for a Dell laptop
  ALSA: es18xx driver should use udelay error
  ALSA: hda/realtek - Add support of ALC288 codec

10 years agoMerge tag 'dt-fixes-for-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/robh...
Linus Torvalds [Fri, 18 Apr 2014 17:19:01 +0000 (10:19 -0700)]
Merge tag 'dt-fixes-for-3.15' of git://git./linux/kernel/git/robh/linux

Pull devicetree fixes from Rob Herring:
 - fix error handling in of_update_property
 - fix section mismatch warnings in __reserved_mem_check_root
 - add empty of_find_node_by_path for !OF builds
 - add various missing binding documentation

* tag 'dt-fixes-for-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  of: add empty of_find_node_by_path() for !OF
  of: Clean up of_update_property
  DT: add vendor prefix for EBV Elektronik
  of: Fix the section mismatch warnings.
  of: Add vendor prefix for Digi International Inc.
  DT: I2C: Add trivial bindings used by kirkwood boards
  DT: Vendor: Add prefixes used by Kirkwood devices
  DT: bindings: add missing Marvell Kirkwood SoC documentation
  dt-bindings: add vendor-prefix for Newhaven Display
  of: add vendor prefix for I2SE GmbH
  of: add vendor prefix for ISEE 2007 S.L.

10 years agoMerge tag 'xfs-for-linus-3.15-rc2' of git://oss.sgi.com/xfs/xfs
Linus Torvalds [Fri, 18 Apr 2014 17:17:37 +0000 (10:17 -0700)]
Merge tag 'xfs-for-linus-3.15-rc2' of git://oss.sgi.com/xfs/xfs

Pull xfs bug fixes from Dave Chinner:
 "The fixes are for data corruption issues, memory corruption and
  regressions for changes merged in -rc1.

  Data corruption fixes:
   - fix a bunch of delayed allocation state mismatches
   - fix collapse/zero range bugs
   - fix a direct IO block mapping bug @ EOF

  Other fixes:
   - fix a use after free on metadata IO error
   - fix a use after free on IO error during unmount
   - fix an incorrect error sign on direct IO write errors
   - add missing O_TMPFILE inode security context initialisation"

* tag 'xfs-for-linus-3.15-rc2' of git://oss.sgi.com/xfs/xfs:
  xfs: fix tmpfile/selinux deadlock and initialize security
  xfs: fix buffer use after free on IO error
  xfs: wrong error sign conversion during failed DIO writes
  xfs: unmount does not wait for shutdown during unmount
  xfs: collapse range is delalloc challenged
  xfs: don't map ranges that span EOF for direct IO
  xfs: zeroing space needs to punch delalloc blocks
  xfs: xfs_vm_write_end truncates too much on failure
  xfs: write failure beyond EOF truncates too much data
  xfs: kill buffers over failed write ranges properly

10 years agoMerge tag 'trace-fixes-v3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Fri, 18 Apr 2014 17:16:43 +0000 (10:16 -0700)]
Merge tag 'trace-fixes-v3.15-rc1' of git://git./linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "This contains two fixes.

  The first is to remove a duplication of creating debugfs files that
  already exist and causes an error report to be printed due to the
  failure of the second creation.

  The second is a memory leak fix that was introduced in 3.14"

* tag 'trace-fixes-v3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/uprobes: Fix uprobe_cpu_buffer memory leak
  tracing: Do not try to recreated toplevel set_ftrace_* files

10 years agoext4: use EINVAL if not a regular file in ext4_collapse_range()
Theodore Ts'o [Fri, 18 Apr 2014 15:52:11 +0000 (11:52 -0400)]
ext4: use EINVAL if not a regular file in ext4_collapse_range()

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
10 years agoext4: enforce we are operating on a regular file in ext4_zero_range()
jon ernst [Fri, 18 Apr 2014 15:50:35 +0000 (11:50 -0400)]
ext4: enforce we are operating on a regular file in ext4_zero_range()

Signed-off-by: Jon Ernst <jonernst07@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
10 years agoext4: fix extent merging in ext4_ext_shift_path_extents()
Lukas Czerner [Fri, 18 Apr 2014 14:55:24 +0000 (10:55 -0400)]
ext4: fix extent merging in ext4_ext_shift_path_extents()

There is a bug in ext4_ext_shift_path_extents() where if we actually
manage to merge a extent we would skip shifting the next extent. This
will result in in one extent in the extent tree not being properly
shifted.

This is causing failure in various xfstests tests using fsx or fsstress
with collapse range support. It will also cause file system corruption
which looks something like:

 e2fsck 1.42.9 (4-Feb-2014)
 Pass 1: Checking inodes, blocks, and sizes
 Inode 20 has out of order extents
        (invalid logical block 3, physical block 492938, len 2)
 Clear? yes
 ...

when running e2fsck.

It's also very easily reproducible just by running fsx without any
parameters. I can usually hit the problem within a minute.

Fix it by increasing ex_start only if we're not merging the extent.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
10 years agoext4: discard preallocations after removing space
Lukas Czerner [Fri, 18 Apr 2014 14:50:23 +0000 (10:50 -0400)]
ext4: discard preallocations after removing space

Currently in ext4_collapse_range() and ext4_punch_hole() we're
discarding preallocation twice. Once before we attempt to do any changes
and second time after we're done with the changes.

While the second call to ext4_discard_preallocations() in
ext4_punch_hole() case is not needed, we need to discard preallocation
right after ext4_ext_remove_space() in collapse range case because in
the case we had to restart a transaction in the middle of removing space
we might have new preallocations created.

Remove unneeded ext4_discard_preallocations() ext4_punch_hole() and move
it to the better place in ext4_collapse_range()

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
10 years agoext4: no need to truncate pagecache twice in collapse range
Lukas Czerner [Fri, 18 Apr 2014 14:48:25 +0000 (10:48 -0400)]
ext4: no need to truncate pagecache twice in collapse range

We're already calling truncate_pagecache() before we attempt to do any
actual job so there is not need to truncate pagecache once more using
truncate_setsize() after we're finished.

Remove truncate_setsize() and replace it just with i_size_write() note
that we're holding appropriate locks.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
10 years agoext4: fix removing status extents in ext4_collapse_range()
Lukas Czerner [Fri, 18 Apr 2014 14:43:21 +0000 (10:43 -0400)]
ext4: fix removing status extents in ext4_collapse_range()

Currently in ext4_collapse_range() when calling ext4_es_remove_extent() to
remove status extents we're passing (EXT_MAX_BLOCKS - punch_start - 1)
in order to remove all extents from start of the collapse range to the
end of the file. However this is wrong because we might miss the
possible extent covering the last block of the file.

Fix it by removing the -1.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
10 years agoext4: use filemap_write_and_wait_range() correctly in collapse range
Lukas Czerner [Fri, 18 Apr 2014 14:41:52 +0000 (10:41 -0400)]
ext4: use filemap_write_and_wait_range() correctly in collapse range

Currently we're passing -1 as lend argumnet for
filemap_write_and_wait_range() which is wrong since lend is signed type
so it would cause some confusion and we might not write_and_wait for the
entire range we're expecting to write.

Fix it by using LLONG_MAX instead.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
10 years agoext4: use truncate_pagecache() in collapse range
Lukas Czerner [Fri, 18 Apr 2014 14:21:15 +0000 (10:21 -0400)]
ext4: use truncate_pagecache() in collapse range

We should be using truncate_pagecache() instead of
truncate_pagecache_range() in the collapse range because we're
truncating page cache from offset to the end of file.
truncate_pagecache() also get rid of the private COWed pages from the
range because we're going to shift the end of the file.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
10 years agoof: add empty of_find_node_by_path() for !OF
Alexander Shiyan [Wed, 16 Apr 2014 06:49:20 +0000 (10:49 +0400)]
of: add empty of_find_node_by_path() for !OF

Add an empty version of of_find_node_by_path().
This fixes following build error for asoc tree:
sound/soc/fsl/fsl_ssi.c: In function 'fsl_ssi_probe':
sound/soc/fsl/fsl_ssi.c:1471:2: error: implicit declaration of function 'of_find_node_by_path' [-Werror=implicit-function-declaration]
  sprop = of_get_property(of_find_node_by_path("/"), "compatible", NULL);

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Rob Herring <robh@kernel.org>
10 years agoperf/x86/intel: Use rdmsrl_safe() when initializing RAPL PMU
Venkatesh Srinivas [Thu, 13 Mar 2014 19:36:26 +0000 (12:36 -0700)]
perf/x86/intel: Use rdmsrl_safe() when initializing RAPL PMU

CPUs which should support the RAPL counters according to
Family/Model/Stepping may still issue #GP when attempting to access
the RAPL MSRs. This may happen when Linux is running under KVM and
we are passing-through host F/M/S data, for example. Use rdmsrl_safe
to first access the RAPL_POWER_UNIT MSR; if this fails, do not
attempt to use this PMU.

Signed-off-by: Venkatesh Srinivas <venkateshs@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1394739386-22260-1-git-send-email-venkateshs@google.com
Cc: zheng.z.yan@intel.com
Cc: eranian@google.com
Cc: ak@linux.intel.com
Cc: linux-kernel@vger.kernel.org
[ The patch also silently fixes another bug: rapl_pmu_init() didn't handle the memory alloc failure case previously. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched: Remove set_need_resched()
Peter Zijlstra [Tue, 8 Apr 2014 12:27:25 +0000 (14:27 +0200)]
sched: Remove set_need_resched()

The last user is gone now, so we can safely remove this function.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <bitbucket@online.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched: Revert commit 4c6c4e38c4e9 ("sched/core: Fix endless loop in pick_next_task()")
Kirill Tkhai [Fri, 14 Mar 2014 22:15:07 +0000 (02:15 +0400)]
sched: Revert commit 4c6c4e38c4e9 ("sched/core: Fix endless loop in pick_next_task()")

This reverts commit 4c6c4e38c4e9 ("sched/core: Fix endless loop in
pick_next_task()"), which is not necessary after ("sched/rt: Substract number
of tasks of throttled queues from rq->nr_running").

Signed-off-by: Kirill Tkhai <tkhai@yandex.ru>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
[conflict resolution with stop task checking patch]
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1394835307.18748.34.camel@HP-250-G1-Notebook-PC
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched/rt: Substract number of tasks of throttled queues from rq->nr_running
Kirill Tkhai [Fri, 14 Mar 2014 22:15:00 +0000 (02:15 +0400)]
sched/rt: Substract number of tasks of throttled queues from rq->nr_running

Now rq->rt becomes to be able to be in dequeued or enqueued state.
We add new member rt_rq->rt_queued, which is used to indicate this.
The member is used only for top queue rq->rt_rq.

The goal is to fit generic scheme which is used in deadline and
fair classes, i.e. throttled rt_rq's rt_nr_running is beeing
substracted from rq->nr_running.

Signed-off-by: Kirill Tkhai <tkhai@yandex.ru>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1394835300.18748.33.camel@HP-250-G1-Notebook-PC
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
10 years agosched/rt: Add accessors rq_of_rt_se()
Kirill Tkhai [Fri, 14 Mar 2014 22:14:55 +0000 (02:14 +0400)]
sched/rt: Add accessors rq_of_rt_se()

Two accessors for RT_GROUP_SCHED and !RT_GROUP_SCHED cases.

Signed-off-by: Kirill Tkhai <tkhai@yandex.ru>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1394835295.18748.32.camel@HP-250-G1-Notebook-PC
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>