Checking "user" before "is_idle_task()" allows better optimizations
in cases where inlining is possible. Also, "bool" should be passed
"true" or "false" rather than "1" or "0". This commit therefore makes
these changes, as noted in Josh's review.
Reported-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Provide a config option that enables the userspace
RCU extended quiescent state on every CPUs by default.
This is for testing purpose.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Alessio Igor Bogani <abogani@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Avi Kivity <avi@redhat.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Max Krasnyansky <maxk@qualcomm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
do_notify_resume() may be called on irq or exception
exit. But at that time the exception has already called
rcu_user_enter() and the irq has already called rcu_irq_exit().
Since it can use RCU read side critical section, we must call
rcu_user_exit() before doing anything there. Then we must call
back rcu_user_enter() after this function because we know we are
going to userspace from there.
This complete support for userspace RCU extended quiescent state
in x86-64.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Alessio Igor Bogani <abogani@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Avi Kivity <avi@redhat.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Max Krasnyansky <maxk@qualcomm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
This way we can exit the RCU extended quiescent state before
we schedule a new task from irq/exception exit.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Alessio Igor Bogani <abogani@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Avi Kivity <avi@redhat.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Max Krasnyansky <maxk@qualcomm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
When exceptions or irq are about to resume userspace, if
the task needs to be rescheduled, the arch low level code
calls schedule() directly.
If we call it, it is because we have the TIF_RESCHED flag:
- It can be set after random local calls to set_need_resched()
(RCU, drm, ...)
- A wake up happened and the CPU needs preemption. This can
happen in several ways:
* Remotely: the remote waking CPU has set TIF_RESCHED and send the
wakee an IPI to schedule the new task.
* Remotely enqueued: the remote waking CPU sends an IPI to the target
and the wake up is made by the target.
* Locally: waking CPU == wakee CPU and the wakeup is done locally.
set_need_resched() is called without IPI.
In the case of local and remotely enqueued wake ups, the tick can
be restarted when we enqueue the new task and RCU can exit the
extended quiescent state at the same time. Then by the time we reach
irq exit path and we call schedule, we are not in RCU user mode.
But if we call schedule() only because something called set_need_resched(),
RCU may still be in user mode when we reach schedule.
Also if a wake up is done remotely, the CPU might see the TIF_RESCHED
flag and call schedule while the IPI has not yet happen to restart the
tick and exit RCU user mode.
We need to manually protect against these corner cases.
Create a new API schedule_user() that calls schedule() inside
rcu_user_exit()-rcu_user_enter() in order to protect it. Archs
will need to rely on it now to implement user preemption safely.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Alessio Igor Bogani <abogani@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Avi Kivity <avi@redhat.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Max Krasnyansky <maxk@qualcomm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
When an exception or an irq exits, and we are going to resume into
interrupted kernel code, the low level architecture code calls
preempt_schedule_irq() if there is a need to reschedule.
If the interrupt/exception occured between a call to rcu_user_enter()
(from syscall exit, exception exit, do_notify_resume exit, ...) and
a real resume to userspace (iret,...), preempt_schedule_irq() can be
called whereas RCU thinks we are in userspace. But preempt_schedule_irq()
is going to run kernel code and may be some RCU read side critical
section. We must exit the userspace extended quiescent state before
we call it.
To solve this, just call rcu_user_exit() in the beginning of
preempt_schedule_irq().
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Alessio Igor Bogani <abogani@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Avi Kivity <avi@redhat.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Max Krasnyansky <maxk@qualcomm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Add necessary hooks to x86 exception for userspace
RCU extended quiescent state support.
This includes traps, page fault, debug exceptions, etc...
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Alessio Igor Bogani <abogani@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Avi Kivity <avi@redhat.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Max Krasnyansky <maxk@qualcomm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
There is some unnatural label based layout in this function.
Convert the unnecessary goto to readable conditional blocks.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Add syscall slow path hooks to notify syscall entry
and exit on CPUs that want to support userspace RCU
extended quiescent state.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Alessio Igor Bogani <abogani@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Avi Kivity <avi@redhat.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Max Krasnyansky <maxk@qualcomm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Clear the syscalls hook of a task when it's scheduled out so that if
the task migrates, it doesn't run the syscall slow path on a CPU
that might not need it.
Also set the syscalls hook on the next task if needed.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Alessio Igor Bogani <abogani@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Avi Kivity <avi@redhat.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Max Krasnyansky <maxk@qualcomm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
By default we don't want to enter into RCU extended quiescent
state while in userspace because doing this produces some overhead
(eg: use of syscall slowpath). Set it off by default and ready to
run when some feature like adaptive tickless need it.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Alessio Igor Bogani <abogani@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Avi Kivity <avi@redhat.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Max Krasnyansky <maxk@qualcomm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Allow calls to rcu_user_enter() even if we are already
in userspace (as seen by RCU) and allow calls to rcu_user_exit()
even if we are already in the kernel.
This makes the APIs more flexible to be called from architectures.
Exception entries for example won't need to know if they come from
userspace before calling rcu_user_exit().
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Alessio Igor Bogani <abogani@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Avi Kivity <avi@redhat.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Max Krasnyansky <maxk@qualcomm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Create a new config option under the RCU menu that put
CPUs under RCU extended quiescent state (as in dynticks
idle mode) when they run in userspace. This require
some contribution from architectures to hook into kernel
and userspace boundaries.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Alessio Igor Bogani <abogani@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Avi Kivity <avi@redhat.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Max Krasnyansky <maxk@qualcomm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
The current implementation of RCU_FAST_NO_HZ tries reasonably hard to rid
the current CPU of RCU callbacks. This is appropriate when the CPU is
entering idle, where it doesn't have much useful to do anyway, but is most
definitely not what you want when transitioning to user-mode execution.
This commit therefore detects the adaptive-tick case, and refrains from
burning CPU time getting rid of RCU callbacks in that case.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
In some cases, it is necessary to enter or exit userspace-RCU-idle mode
from an interrupt handler, for example, if some other CPU sends this
CPU a resched IPI. In this case, the current CPU would enter the IPI
handler in userspace-RCU-idle mode, but would need to exit the IPI handler
after having exited that mode.
To allow this to work, this commit adds two new APIs to TREE_RCU:
- rcu_user_enter_after_irq(). This must be called from an interrupt between
rcu_irq_enter() and rcu_irq_exit(). After the irq calls rcu_irq_exit(),
the irq handler will return into an RCU extended quiescent state.
In theory, this interrupt is never a nested interrupt, but in practice
it might interrupt softirq, which looks to RCU like a nested interrupt.
- rcu_user_exit_after_irq(). This must be called from a non-nesting
interrupt, interrupting an RCU extended quiescent state, also
between rcu_irq_enter() and rcu_irq_exit(). After the irq calls
rcu_irq_exit(), the irq handler will return in an RCU non-quiescent
state.
[ Combined with "Allow calls to rcu_exit_user_irq from nesting irqs." ]
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
RCU currently insists that only idle tasks can enter RCU idle mode, which
prohibits an adaptive tickless kernel (AKA nohz cpusets), which in turn
would mean that usermode execution would always take scheduling-clock
interrupts, even when there is only one task runnable on the CPU in
question.
This commit therefore adds rcu_user_enter() and rcu_user_exit(), which
allow non-idle tasks to enter RCU idle mode. These are quite similar
to rcu_idle_enter() and rcu_idle_exit(), respectively, except that they
omit the idle-task checks.
[ Updated to use "user" flag rather than separate check functions. ]
[ paulmck: Updated to drop exports of new functions based on Josh's patch
getting rid of the need for them. ]
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Alessio Igor Bogani <abogani@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Avi Kivity <avi@redhat.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Max Krasnyansky <maxk@qualcomm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Otherwise when X starts we commonly get a black screen scanning
out nothing, its wierd dpms on/off from userspace brings it back,
With this on F18, multi-seat works again with my 1920x1200 monitor
which is above the sku limit for the device I have.
Cc: stable@vger.kernel.org
Reviewed-by: Alex Deucher <alexander.deucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
We don't allocate enough data for this struct. As soon as we start
modifying event->event on the next lines, then we're going beyond the
end of the memory we allocated.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@gmail.com>
These just silence some printks that we are seeing that we shouldn't
* 'drm-nouveau-fixes' of git://anongit.freedesktop.org/git/nouveau/linux-2.6:
drm/nvc0/ltcg: mask off intr 0x10
drm/nouveau: silence a debug message triggered by newer userspace
Pull v3.7 RCU commits from Paul E. McKenney:
"
0. A fix for a latent bug that has been in RCU ever since the
addition of CPU stall warnings. This bug results in
false-positive stall warnings, but thus far only on embedded
systems with severely cut-down userspace configurations.
This fix is located on an rcu/urgent branch, with the rest
of the commits based on top of it. This commit CCs stable.
Given that the merge window is coming quite soon and given
the small number of affected users, I do -not- recommend
pushing it to 3.6, but the separate branch makes it easy to
find if someone needs it.
1. Further reductions in latency spikes for huge systems, along
with additional boot-time adaptation to the actual hardware.
This is a large change, as it moves RCU grace-period
initialization and cleanup, along with quiescent-state forcing,
from softirq to a kthread. However, it appears to be in
quite good shape (famous last words). Posted to LKML at
https://lkml.org/lkml/2012/9/20/427.
2. Updates to documentation and rcutorture, the latter category
including keeping statistics on CPU-hotplug latencies and
fixing some initialization-time races. Posted to LKML at
https://lkml.org/lkml/2012/8/30/193.
3. Miscellaneous fixes and improvements, posted to LKML at
https://lkml.org/lkml/2012/8/30/199.
4. CPU-hotplug fixes and improvements, posted to LKML at
https://lkml.org/lkml/2012/8/30/292 for first three and at
https://lkml.org/lkml/2012/8/3/416.
5. Idle-loop fixes that were omitted on an earlier submission,
posted to LKML at https://lkml.org/lkml/2012/8/30/251.
"
Signed-off-by: Ingo Molnar <mingo@kernel.org>
. The new perf_evsel__tp_sched_test 'perf test' broke the build by setting the
'ret' variable but not using it, caught by newer gcc
-Werror=unused-but-set-variable, fix from Namhyung Kim.
. pevent_parse_event should return a proper PEVENT_ERRNO__ and call
pevent_free_format on its failure path, fixes from Namhyung Kim.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core
Pull perf/core fixes from Arnaldo Carvalho de Melo:
* The new perf_evsel__tp_sched_test 'perf test' broke the build by setting the
'ret' variable but not using it, caught by newer gcc
-Werror=unused-but-set-variable, fix from Namhyung Kim.
* pevent_parse_event should return a proper PEVENT_ERRNO__ and call
pevent_free_format on its failure path, fixes from Namhyung Kim.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
NVIDIA do that at startup too on Fermi, so perhaps the heap of 0x10
intrs we receive are normal and we can ignore them.
On Kepler NVIDIA *don't* do this, but the hardware appears to come up
with the bit masked off by default - so that's probably why :)
This should silence some interrupt spam seen on Fermi+ boards.
Backported patch from reworked nouveau kernel tree.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Commit v2.6.19-rc1~1272^2~41 tells us that r->cost != 0 can happen when
a running state is saved to userspace and then reinstated from there.
Make sure that private xt_limit area is initialized with correct values.
Otherwise, random matchings due to use of uninitialized memory.
Signed-off-by: Jan Engelhardt <jengelh@inai.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pull more networking fixes from David Miller:
1) Eric Dumazet discovered and fixed what turned out to be a family of
bugs. These functions were using pskb_may_pull() which might need
to reallocate the linear SKB data buffer, but the callers were not
expecting this possibility. The callers have cached pointers to the
packet header areas, and would need to reload them if we were to
continue using pskb_may_pull().
So they could end up reading garbage.
It's easier to just change these RAW4/RAW6/MIP6 routines to use
skb_header_pointer() instead of pskb_may_pull(), which won't modify
the linear SKB data area.
2) Dave Jone's syscall spammer caught a case where a non-TCP socket can
call down into the TCP keepalive code. The case basically involves
creating a raw socket with sk_protocol == IPPROTO_TCP, then calling
setsockopt(sock_fd, SO_KEEPALIVE, ...)
Fixed by Eric Dumazet.
3) Bluetooth devices do not get configured properly while being powered
on, resulting in always using legacy pairing instead of SSP. Fix
from Andrzej Kaczmarek.
4) Bluetooth cancels delayed work erroneously, put stricter checks in
place. From Andrei Emeltchenko.
5) Fix deadlock between cfg80211_mutex and reg_regdb_search_mutex in
cfg80211, from Luis R. Rodriguez.
6) Fix interrupt double release in iwlwifi, from Emmanuel Grumbach.
7) Missing module license in bcm87xx driver, from Peter Huewe.
8) Team driver can lose port changed events when adding devices to a
team, fix from Jiri Pirko.
9) Fix endless loop when trying ot unregister PPPOE device in zombie
state, from Xiaodong Xu.
10) batman-adv layer needs to set MAC address of software device
earlier, otherwise we call tt_local_add with it uninitialized.
11) Fix handling of KSZ8021 PHYs, it's matched currently by KS8051 but
that doesn't program the device properly. From Marek Vasut.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
ipv6: mip6: fix mip6_mh_filter()
ipv6: raw: fix icmpv6_filter()
net: guard tcp_set_keepalive() to tcp sockets
phy/micrel: Add missing header to micrel_phy.h
phy/micrel: Rename KS80xx to KSZ80xx
phy/micrel: Implement support for KSZ8021
batman-adv: Fix symmetry check / route flapping in multi interface setups
batman-adv: Fix change mac address of soft iface.
pppoe: drop PPPOX_ZOMBIEs in pppoe_release
team: send port changed when added
ipv4: raw: fix icmp_filter()
net/phy/bcm87xx: Add MODULE_LICENSE("GPL") to GPL driver
iwlwifi: don't double free the interrupt in failure path
cfg80211: fix possible circular lock on reg_regdb_search()
Bluetooth: Fix not removing power_off delayed work
Bluetooth: Fix freeing uninitialized delayed works
Bluetooth: mgmt: Fix enabling LE while powered off
Bluetooth: mgmt: Fix enabling SSP while powered off
mip6_mh_filter() should not modify its input, or else its caller
would need to recompute ipv6_hdr() if skb->head is reallocated.
Use skb_header_pointer() instead of pskb_may_pull()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
- fix the behaviour of batman-adv in case of virtual interface MAC change event
- fix symmetric link check in neighbour selection
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Merge tag 'batman-adv-fix-for-davem' of git://git.open-mesh.org/linux-merge
Included fixes:
- fix the behaviour of batman-adv in case of virtual interface MAC change event
- fix symmetric link check in neighbour selection
Signed-off-by: David S. Miller <davem@davemloft.net>
icmpv6_filter() should not modify its input, or else its caller
would need to recompute ipv6_hdr() if skb->head is reallocated.
Use skb_header_pointer() instead of pskb_may_pull() and
change the prototype to make clear both sk and skb are const.
Also, if icmpv6 header cannot be found, do not deliver the packet,
as we do in IPv4.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The conflicts between kernel/rcutree.h and kernel/rcutree_plugin.h
were due to adjacent insertions and deletions, which were resolved
by simply accepting the changes on both branches.
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Merge tag 'sh-for-linus' of git://github.com/pmundt/linux-sh
Pull SuperH fix from Paul Mundt:
"One last minute regression fix.."
* tag 'sh-for-linus' of git://github.com/pmundt/linux-sh:
sh: pfc: Fix up GPIO mux type reconfig case.
Merge misc fixes from Andrew Morton:
"One maintainer change and three bugfixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (4 commits)
c/r: prctl: fix build error for no-MMU case
lib/flex_proportions.c: fix corruption of denominator in flexible proportions
checksyscalls: fix "here document" handling
pwm-backlight: take over maintenance
Commit 1ad75b9e16 ("c/r: prctl: add minimal address test to
PR_SET_MM") added some address checking to prctl_set_mm() used by
checkpoint-restore. This causes a build error for no-MMU systems:
kernel/sys.c: In function 'prctl_set_mm':
kernel/sys.c:1868:34: error: 'mmap_min_addr' undeclared (first use in this function)
The test for mmap_min_addr doesn't make a lot of sense for no-MMU code
as noted in commit 6e14154676 ("NOMMU: Optimise away the
{dac_,}mmap_min_addr tests").
This patch defines mmap_min_addr as 0UL in the no-MMU case so that the
compiler will optimize away tests for "addr < mmap_min_addr".
Signed-off-by: Mark Salter <msalter@redhat.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: <stable@vger.kernel.org> [3.6.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When racing with CPU hotplug, percpu_counter_sum() can return negative
values for the number of observed events.
This confuses fprop_new_period(), which uses unsigned type and as a
result number of events is set to big *positive* number. From that
moment on, things go pear shaped and can result e.g. in division by
zero as denominator is later truncated to 32-bits.
This bug causes a divide-by-zero oops in bdi_dirty_limit() in Borislav's
3.6.0-rc6 based kernel.
Fix the issue by using a signed type in fprop_new_period(). That makes
us bail out from the function without doing anything (mistakenly)
thinking there are no events to age. That makes aging somewhat
inaccurate but getting accurate data would be rather hard.
Signed-off-by: Jan Kara <jack@suse.cz>
Reported-by: Borislav Petkov <bp@amd64.org>
Reported-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
"echo" doesn't read from stdin, therefore the checksyscalls script didn't
warn about not implemented system calls anymore since 29dc54c6
("checksyscalls: Use arch/x86/syscalls/syscall_32.tbl as source").
Use "cat" instead of "echo" which handles this correctly.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Michal Marek <mmarek@suse.cz>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since the pwm-backlight driver is lacking a proper maintainer and is the
heaviest user of the PWM framework I'm taking over maintenance.
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Acked-by: Arun Murthy <arun.murthy@stericsson.com>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Robert Morell <rmorell@nvidia.com>
Cc: Dilan Lee <dilee@nvidia.com>
Cc: Axel Lin <axel.lin@gmail.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is no known reason for this option to be unavailable on other
archs than x86. They just need to call enable_sched_clock_irqtime()
if they have a sufficiently finegrained clock to make it working.
Move it to the general option and let the user choose between
it and pure tick based or virtual cputime accounting.
Note that virtual cputime accounting already performs a finegrained
irqtime accounting. CONFIG_IRQ_TIME_ACCOUNTING is a kind of middle ground
between tick and virtual based accounting. So CONFIG_IRQ_TIME_ACCOUNTING
and CONFIG_VIRT_CPU_ACCOUNTING are mutually exclusive choices.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
This debloats a bit the general config menu and make these
config options easier to find.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Factorize the code that accounts user time into a
single function to avoid code duplication.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Move the code that finds out to which context we account the
cputime into generic layer.
Archs that consider the whole time spent in the idle task as idle
time (ia64, powerpc) can rely on the generic vtime_account()
and implement vtime_account_system() and vtime_account_idle(),
letting the generic code to decide when to call which API.
Archs that have their own meaning of idle time, such as s390
that only considers the time spent in CPU low power mode as idle
time, can just override vtime_account().
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
The lg4ff driver doesn't fill the "input_absinfo" struct so it is left
with default values. Applications with rely on information in this struct
therefore do not work correctly with the wheel.
Other Logitech wheels probably need this fix too, but again I do not have
enough information to write it.
Signed-off-by: Michal Malý <madcatxster@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Range limiting command for the Driving Force Pro wheel is only a FF_SPRING
effect so that the wheel creates resistance when the user tries to turn it past
the limit. It is however possible to overpower the FFB motors quite easily which
leads to the X axis value exceeding the expected limit. This confuses
games which dynamically adjust calibration using the highest/lowest min and max
values reported by the wheel. Joydev device driver also doesn't take in account
any changes in an axis range after the joystick device is created.
This patch recalculates received ABS_X axis value so it is always in
<0; 16383> range where 0 is the left limit and 16383 the right limit.
Logitech driver for Windows does the same thing. As for any concerns about
possible loss of precision, I compared a large set of raw/adjusted values
generated by "mult_frac" to values returned by the Windows driver and I got
a 100% match.
Other Logitech wheels will probably need a similar fix, but I currently lack
the information needed to write one.
Signed-off-by: Michal Malý <madcatxster@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This patch replaces all occurrences of "report->field[0]->value[n]" with just
"value[n]" to get rid of the lengthy trains we have now.
Signed-off-by: Michal Malý <madcatxster@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Use a naming based on vtime as a prefix for virtual based
cputime accounting APIs:
- account_system_vtime() -> vtime_account()
- account_switch_vtime() -> vtime_task_switch()
It makes it easier to allow for further declension such
as vtime_account_system(), vtime_account_idle(), ... if we
want to find out the context we account to from generic code.
This also make it better to know on which subsystem these APIs
refer to.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Since something will be divided by these variables in
show_min_width()/show_min_height() and show_activate_width()/
show_activate_height(), a divided error would be triggered if
they are zero.
Signed-off-by: Wen-chien Jesse Sung <jesse.sung@canonical.com>
Acked-by: Rafi Rubin <rafi@seas.upenn.edu>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
If __pevent_parse_format() succeeded but add_event() failed, 'ret' didn't
have a proper error code. Set it to PEVENT_ERRNO__MEM_ALLOC_FAILED.
In addition, at that point 'event' also has fields and format
information and they all need to be freed. Call pevent_free_format() to
handle it.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1348575919-4954-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
