It is now unused, remove it before someone else thinks its a good idea
to use this.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
stop_two_cpus() and stop_cpus() use stop_cpus_lock to avoid the deadlock,
we need to ensure that the stopper functions can't be queued "backwards"
from one another. This doesn't look nice; if we use lglock then we do not
really need stopper->lock, cpu_stop_queue_work() could use lg_local_lock()
under local_irq_save().
OTOH it would be even better to avoid lglock in stop_machine.c and remove
lg_double_lock(). This patch adds "bool stop_cpus_in_progress" set/cleared
by queue_stop_cpus_work(), and changes cpu_stop_queue_two_works() to busy
wait until it is cleared.
queue_stop_cpus_work() sets stop_cpus_in_progress = T lockless, but after
it queues a work on CPU1 it must be visible to stop_two_cpus(CPU1, CPU2)
which checks it under the same lock. And since stop_two_cpus() holds the
2nd lock too, queue_stop_cpus_work() can not clear stop_cpus_in_progress
if it is also going to queue a work on CPU2, it needs to take that 2nd
lock to do this.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20151121181148.GA433@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
SCHED_HRTICK feature is useful to preempt SCHED_FAIR tasks on-the-dot
(just when they would have exceeded their ideal_runtime).
It makes use of a per-CPU hrtimer resource and hence arming that
hrtimer should be based on total SCHED_FAIR tasks a CPU has across its
various cfs_rqs, rather than being based on number of tasks in a
particular cfs_rq (as implemented currently).
As a result, with current code, its possible for a running task (which
is the sole task in its cfs_rq) to be preempted much after its
ideal_runtime has elapsed, resulting in increased latency for tasks in
other cfs_rq on same CPU.
Fix this by arming sched hrtimer based on total number of SCHED_FAIR
tasks a CPU has across its various cfs_rqs.
Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org>
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1474075731-11550-1-git-send-email-joonwoop@codeaurora.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
An "exclusive" PMU is the one that can only have one event scheduled in
at any given time. There may be more than one of such PMUs in a system,
though, like Intel PT and BTS. It should be allowed to have one event
for either of those inside the same context (there may be other constraints
that may prevent this, but those would be hardware-specific). However,
the exclusivity code is written so that only one event from any of the
"exclusive" PMUs is allowed in a context.
Fix this by making the exclusive event filter explicitly match two events'
PMUs.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160920154811.3255-3-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
On fully preemptible kernels _cond_resched() is pointless, so avoid
emitting any code for it.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Oleg noted that by making do_exit() use __schedule() for the TASK_DEAD
context switch, we can avoid the TASK_DEAD special case currently in
__schedule() because that avoids the extra preempt_disable() from
schedule().
In order to facilitate this, create a do_task_dead() helper which we
place in the scheduler code, such that it can access __schedule().
Also add some __noreturn annotations to the functions, there's no
coming back from do_exit().
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Cheng Chao <cs.os.kernel@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akpm@linux-foundation.org
Cc: chris@chris-wilson.co.uk
Cc: tj@kernel.org
Link: http://lkml.kernel.org/r/20160913163729.GB5012@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In case @cpu == smp_proccessor_id(), we can avoid a sleep+wakeup
cycle by doing a preemption.
Callers such as sched_exec() can benefit from this change.
Signed-off-by: Cheng Chao <cs.os.kernel@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akpm@linux-foundation.org
Cc: chris@chris-wilson.co.uk
Cc: tj@kernel.org
Link: http://lkml.kernel.org/r/1473818510-6779-1-git-send-email-cs.os.kernel@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The SMP IPI struct descriptor is allocated on the stack except for the
workqueue and lockdep complains:
INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
CPU: 0 PID: 110 Comm: kworker/0:1 Not tainted 4.8.0-rc5+ #14
Hardware name: Dell Inc. Precision T3600/0PTTT9, BIOS A13 05/11/2014
Workqueue: events smp_call_on_cpu_callback
...
Call Trace:
dump_stack
register_lock_class
? __lock_acquire
__lock_acquire
? __lock_acquire
lock_acquire
? process_one_work
process_one_work
? process_one_work
worker_thread
? process_one_work
? process_one_work
kthread
? kthread_create_on_node
ret_from_fork
So allocate it on the stack too.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[ Test and write commit message. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160911084323.jhtnpb4b37t5tlno@pd.tnic
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We should not be using smp_processor_id() with preempt enabled.
Bug identified and fix provided by Alfred Chen.
Reported-by: Alfred Chen <cchalpha@gmail.com>
Signed-off-by: Con Kolivas <kernel@kolivas.org>
Cc: Alfred Chen <cchalpha@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/2042051.3vvUWIM0vs@hex
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When a socket is cloned, the associated sock_cgroup_data is duplicated
but not its reference on the cgroup. As a result, the cgroup reference
count will underflow when both sockets are destroyed later on.
Fixes: bd1060a1d6 ("sock, cgroup: add sock->sk_cgroup")
Link: http://lkml.kernel.org/r/20160914194846.11153-2-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: <stable@vger.kernel.org> [4.5+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Install the callbacks via the state machine. CPU-hotplug multinstance support
is used with the nocalls() version. Maybe parts of padata_alloc() could be
moved into the online callback so that we could invoke ->startup callback for
instance and drop get_online_cpus().
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-crypto@vger.kernel.org
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160906170457.32393-14-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
There is no point in trying to configure the trigger of a chained
interrupt if no trigger information has been configured. At best
this is ignored, and at the worse this confuses the underlying
irqchip (which is likely not to handle such a thing), and
unnecessarily alarms the user.
Only apply the configuration if type is not IRQ_TYPE_NONE.
Fixes: 1e12c4a939 ("genirq: Correctly configure the trigger on chained interrupts")
Reported-and-tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/CAMuHMdVW1eTn20=EtYcJ8hkVwohaSuH_yQXrY2MGBEvZ8fpFOg@mail.gmail.com
Link: http://lkml.kernel.org/r/1474274967-15984-1-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Fixes the following sparse warning:
kernel/cpuset.c:2088:6: warning:
symbol 'cpuset_fork' was not declared. Should it be static?
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
vmalloc() is a bit slow, and pounding vmalloc()/vfree() will eventually
force a global TLB flush.
To reduce pressure on them, if CONFIG_VMAP_STACK=y, cache two thread
stacks per CPU. This will let us quickly allocate a hopefully
cache-hot, TLB-hot stack under heavy forking workloads (shell script style).
On my silly pthread_create() benchmark, it saves about 2 µs per
pthread_create()+join() with CONFIG_VMAP_STACK=y.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jann Horn <jann@thejh.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/94811d8e3994b2e962f88866290017d498eb069c.1474003868.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We currently keep every task's stack around until the task_struct
itself is freed. This means that we keep the stack allocation alive
for longer than necessary and that, under load, we free stacks in
big batches whenever RCU drops the last task reference. Neither of
these is good for reuse of cache-hot memory, and freeing in batches
prevents us from usefully caching small numbers of vmalloced stacks.
On architectures that have thread_info on the stack, we can't easily
change this, but on architectures that set THREAD_INFO_IN_TASK, we
can free it as soon as the task is dead.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jann Horn <jann@thejh.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/08ca06cde00ebed0046c5d26cbbf3fbb7ef5b812.1474003868.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
get_task_struct(tsk) no longer pins tsk->stack so all users of
to_live_kthread() should do try_get_task_stack/put_task_stack to protect
"struct kthread" which lives on kthread's stack.
TODO: Kill to_live_kthread(), perhaps we can even kill "struct kthread" too,
and rework kthread_stop(), it can use task_work_add() to sync with the exiting
kernel thread.
Message-Id: <20160629180357.GA7178@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jann Horn <jann@thejh.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/cb9b16bbc19d4aea4507ab0552e4644c1211d130.1474003868.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull RCU changes from Paul E. McKenney:
- Expedited grace-period changes, most notably avoiding having
user threads drive expedited grace periods, using a workqueue
instead.
- Miscellaneous fixes, including a performance fix for lists
that was sent with the lists modifications (second URL below).
- CPU hotplug updates, most notably providing exact CPU-online
tracking for RCU. This will in turn allow removal of the
checks supporting RCU's prior heuristic that was based on the
assumption that CPUs would take no longer than one jiffy to
come online.
- Torture-test updates.
- Documentation updates.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If an arch opts in by setting CONFIG_THREAD_INFO_IN_TASK_STRUCT,
then thread_info is defined as a single 'u32 flags' and is the first
entry of task_struct. thread_info::task is removed (it serves no
purpose if thread_info is embedded in task_struct), and
thread_info::cpu gets its own slot in task_struct.
This is heavily based on a patch written by Linus.
Originally-from: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jann Horn <jann@thejh.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/a0898196f0476195ca02713691a5037a14f2aac5.1473801993.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The current irq spreading infrastructure is just looking at a cpumask and
tries to spread the interrupts over the mask. Thats suboptimal as it does
not take numa nodes into account.
Change the logic so the interrupts are spread across numa nodes and inside
the nodes. If there are more cpus than vectors per node, then we set the
affinity to several cpus. If HT siblings are available we take that into
account and try to set all siblings to a single vector.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: axboe@fb.com
Cc: keith.busch@intel.com
Cc: agordeev@redhat.com
Cc: linux-block@vger.kernel.org
Link: http://lkml.kernel.org/r/1473862739-15032-3-git-send-email-hch@lst.de
For irq spreading want to store affinity masks in the msi_entry. Add the
infrastructure for it.
We allocate an array of cpumasks with an array size of the number of used
vectors in the entry, so we can hand in the information per linux interrupt
later.
As we hand in the number of used vectors, we assign them right
away. Convert all the call sites.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: axboe@fb.com
Cc: keith.busch@intel.com
Cc: agordeev@redhat.com
Cc: linux-block@vger.kernel.org
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/1473862739-15032-2-git-send-email-hch@lst.de
Introduce new flags that defines which ABI to use on creating sigframe.
Those flags kernel will set according to sigaction syscall ABI,
which set handler for the signal being delivered.
So that will drop the dependency on TIF_IA32/TIF_X32 flags on signal deliver.
Those flags will be used only under CONFIG_COMPAT.
Similar way ARM uses sa_flags to differ in which mode deliver signal
for 26-bit applications (look at SA_THIRYTWO).
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: 0x7f454c46@gmail.com
Cc: oleg@redhat.com
Cc: linux-mm@kvack.org
Cc: gorcunov@openvz.org
Cc: xemul@virtuozzo.com
Link: http://lkml.kernel.org/r/20160905133308.28234-7-dsafonov@virtuozzo.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
- ACPI IORT core code
- IORT support for the GICv3 ITS
- A few of GIC cleanups
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=Xhg0
-----END PGP SIGNATURE-----
Merge tag 'irqchip-4.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core
Merge the first drop of irqchip updates for 4.9 from Marc Zyngier:
- ACPI IORT core code
- IORT support for the GICv3 ITS
- A few of GIC cleanups
Information about interrupts is exposed via /proc/interrupts, but the
format of that file has changed over kernel versions and differs across
architectures. It also has varying column numbers depending on hardware.
That all makes it hard for tools to parse.
To solve this, expose the information through sysfs so each irq attribute
is in a separate file in a consistent, machine parsable way.
This feature is only available when both CONFIG_SPARSE_IRQ and
CONFIG_SYSFS are enabled.
Examples:
/sys/kernel/irq/18/actions: i801_smbus,ehci_hcd:usb1,uhci_hcd:usb7
/sys/kernel/irq/18/chip_name: IR-IO-APIC
/sys/kernel/irq/18/hwirq: 18
/sys/kernel/irq/18/name: fasteoi
/sys/kernel/irq/18/per_cpu_count: 0,0
/sys/kernel/irq/18/type: level
/sys/kernel/irq/25/actions: ahci0
/sys/kernel/irq/25/chip_name: IR-PCI-MSI
/sys/kernel/irq/25/hwirq: 512000
/sys/kernel/irq/25/name: edge
/sys/kernel/irq/25/per_cpu_count: 29036,0
/sys/kernel/irq/25/type: edge
[ tglx: Moved kobject_del() under sparse_irq_lock, massaged code comments
and changelog ]
Signed-off-by: Craig Gallek <kraig@google.com>
Cc: David Decotigny <decot@google.com>
Link: http://lkml.kernel.org/r/1473783291-122873-1-git-send-email-kraigatgoog@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Modify the schedutil cpufreq governor to boost the CPU
frequency if the SCHED_CPUFREQ_IOWAIT flag is passed to
it via cpufreq_update_util().
If that happens, the frequency is set to the maximum during
the first update after receiving the SCHED_CPUFREQ_IOWAIT flag
and then the boost is reduced by half during each following update.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Looks-good-to: Steve Muckle <smuckle@linaro.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Testing indicates that it is possible to improve performace
significantly without increasing energy consumption too much by
teaching cpufreq governors to bump up the CPU performance level if
the in_iowait flag is set for the task in enqueue_task_fair().
For this purpose, define a new cpufreq_update_util() flag
SCHED_CPUFREQ_IOWAIT and modify enqueue_task_fair() to pass that
flag to cpufreq_update_util() in the in_iowait case. That generally
requires cpufreq_update_util() to be called directly from there,
because update_load_avg() may not be invoked in that case.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Looks-good-to: Steve Muckle <smuckle@linaro.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Pull scheduler fix from Ingo Molnar:
"A try_to_wake_up() memory ordering race fix causing a busy-loop in
ttwu()"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/core: Fix a race between try_to_wake_up() and a woken up task
Pull perf fixes from Ingo Molnar:
"This contains:
- a set of fixes found by directed-random perf fuzzing efforts by
Vince Weaver, Alexander Shishkin and Peter Zijlstra
- a cqm driver crash fix
- an AMD uncore driver use after free fix"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel: Fix PEBSv3 record drain
perf/x86/intel/bts: Kill a silly warning
perf/x86/intel/bts: Fix BTS PMI detection
perf/x86/intel/bts: Fix confused ordering of PMU callbacks
perf/core: Fix aux_mmap_count vs aux_refcount order
perf/core: Fix a race between mmap_close() and set_output() of AUX events
perf/x86/amd/uncore: Prevent use after free
perf/x86/intel/cqm: Check cqm/mbm enabled state in event init
perf/core: Remove WARN from perf_event_read()
can_stop_full_tick() has no check for offline cpus. So it allows to stop
the tick on an offline cpu from the interrupt return path, which is wrong
and subsequently makes irq_work_needs_cpu() warn about being called for an
offline cpu.
Commit f7ea0fd639 ("tick: Don't invoke tick_nohz_stop_sched_tick() if
the cpu is offline") added prevention for can_stop_idle_tick(), but forgot
to do the same in can_stop_full_tick(). Add it.
[ tglx: Massaged changelog ]
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1473245473-4463-1-git-send-email-wanpeng.li@hotmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
A discrepancy between cpu_online_mask and cpuset's effective_cpus
mask is inevitable during hotplug since cpuset defers updating of
effective_cpus mask using a workqueue, during which time nothing
prevents the system from more hotplug operations. For that reason
guarantee_online_cpus() walks up the cpuset hierarchy until it finds
an intersection under the assumption that top cpuset's effective_cpus
mask intersects with cpu_online_mask even with such a race occurring.
However a sequence of CPU hotplugs can open a time window, during which
none of the effective CPUs in the top cpuset intersect with
cpu_online_mask.
For example when there are 4 possible CPUs 0-3 and only CPU0 is online:
======================== ===========================
cpu_online_mask top_cpuset.effective_cpus
======================== ===========================
echo 1 > cpu2/online.
CPU hotplug notifier woke up hotplug work but not yet scheduled.
[0,2] [0]
echo 0 > cpu0/online.
The workqueue is still runnable.
[2] [0]
======================== ===========================
Now there is no intersection between cpu_online_mask and
top_cpuset.effective_cpus. Thus invoking sys_sched_setaffinity() at
this moment can cause following:
Unable to handle kernel NULL pointer dereference at virtual address 000000d0
------------[ cut here ]------------
Kernel BUG at ffffffc0001389b0 [verbose debug info unavailable]
Internal error: Oops - BUG: 96000005 [#1] PREEMPT SMP
Modules linked in:
CPU: 2 PID: 1420 Comm: taskset Tainted: G W 4.4.8+ #98
task: ffffffc06a5c4880 ti: ffffffc06e124000 task.ti: ffffffc06e124000
PC is at guarantee_online_cpus+0x2c/0x58
LR is at cpuset_cpus_allowed+0x4c/0x6c
<snip>
Process taskset (pid: 1420, stack limit = 0xffffffc06e124020)
Call trace:
[<ffffffc0001389b0>] guarantee_online_cpus+0x2c/0x58
[<ffffffc00013b208>] cpuset_cpus_allowed+0x4c/0x6c
[<ffffffc0000d61f0>] sched_setaffinity+0xc0/0x1ac
[<ffffffc0000d6374>] SyS_sched_setaffinity+0x98/0xac
[<ffffffc000085cb0>] el0_svc_naked+0x24/0x28
The top cpuset's effective_cpus are guaranteed to be identical to
cpu_online_mask eventually. Hence fall back to cpu_online_mask when
there is no intersection between top cpuset's effective_cpus and
cpu_online_mask.
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: cgroups@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: <stable@vger.kernel.org> # 3.17+
Signed-off-by: Tejun Heo <tj@kernel.org>
PAGE_POISONING_ZERO disables zeroing new pages on alloc, they are
poisoned (zeroed) as they become available.
In the hibernate use case, free pages will appear in the system without
being cleared, left there by the loading kernel.
This patch will make sure free pages are cleared on resume when
PAGE_POISONING_ZERO is enabled. We free the pages just after resume
because we can't do it later: going through any device resume code might
allocate some memory and invalidate the free pages bitmap.
Thus we don't need to disable hibernation when PAGE_POISONING_ZERO is
enabled.
Signed-off-by: Anisse Astier <anisse@astier.eu>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Suspend-to-idle (aka the "freeze" sleep state) is a system sleep state
in which all of the processors enter deepest possible idle state and
wait for interrupts right after suspending all the devices.
There is no hard requirement for a platform to support and register
platform specific suspend_ops to enter suspend-to-idle/freeze state.
Only deeper system sleep states like PM_SUSPEND_STANDBY and
PM_SUSPEND_MEM rely on such low level support/implementation.
suspend-to-idle can be entered as along as all the devices can be
suspended. This patch enables the support for suspend-to-idle even on
systems that don't have any low level support for deeper system sleep
states and/or don't register any platform specific suspend_ops.
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Recently we have a new report that, the harddisk can not
resume on time due to firmware issues, and got a kernel
panic because of DPM watchdog timeout. So adjust the
default timeout from 60 to 120 to survive on this platform,
and make DPM_WATCHDOG depending on EXPERT.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=117971
Suggested-by: Pavel Machek <pavel@ucw.cz>
Suggested-by: Rafael J. Wysocki <rafael@kernel.org>
Reported-by: Higuita <higuita@gmx.net>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull libnvdimm fixes from Dan Williams:
"nvdimm fixes for v4.8, two of them are tagged for -stable:
- Fix devm_memremap_pages() to use track_pfn_insert(). Otherwise,
DAX pmd mappings end up with an uncached pgprot, and unusable
performance for the device-dax interface. The device-dax interface
appeared in 4.7 so this is tagged for -stable.
- Fix a couple VM_BUG_ON() checks in the show_smaps() path to
understand DAX pmd entries. This fix is tagged for -stable.
- Fix a mis-merge of the nfit machine-check handler to flip the
polarity of an if() to match the final version of the patch that
Vishal sent for 4.8-rc1. Without this the nfit machine check
handler never detects / inserts new 'badblocks' entries which
applications use to identify lost portions of files.
- For test purposes, fix the nvdimm_clear_poison() path to operate on
legacy / simulated nvdimm memory ranges. Without this fix a test
can set badblocks, but never clear them on these ranges.
- Fix the range checking done by dax_dev_pmd_fault(). This is not
tagged for -stable since this problem is mitigated by specifying
aligned resources at device-dax setup time.
These patches have appeared in a next release over the past week. The
recent rebase you can see in the timestamps was to drop an invalid fix
as identified by the updated device-dax unit tests [1]. The -mm
touches have an ack from Andrew"
[1]: "[ndctl PATCH 0/3] device-dax test for recent kernel bugs"
https://lists.01.org/pipermail/linux-nvdimm/2016-September/006855.html
* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
libnvdimm: allow legacy (e820) pmem region to clear bad blocks
nfit, mce: Fix SPA matching logic in MCE handler
mm: fix cache mode of dax pmd mappings
mm: fix show_smap() for zone_device-pmd ranges
dax: fix mapping size check
There's a bug in this commit:
97a7142f15 ("sched/fair: Make update_min_vruntime() more readable")
... when !rb_leftmost && curr we fail to advance min_vruntime.
So revert it.
Reported-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The order of accesses to ring buffer's aux_mmap_count and aux_refcount
has to be preserved across the users, namely perf_mmap_close() and
perf_aux_output_begin(), otherwise the inversion can result in the latter
holding the last reference to the aux buffer and subsequently free'ing
it in atomic context, triggering a warning.
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 257 at kernel/events/ring_buffer.c:541 __rb_free_aux+0x11a/0x130
> CPU: 0 PID: 257 Comm: stopbug Not tainted 4.8.0-rc1+ #2596
> Call Trace:
> [<ffffffff810f3e0b>] __warn+0xcb/0xf0
> [<ffffffff810f3f3d>] warn_slowpath_null+0x1d/0x20
> [<ffffffff8121182a>] __rb_free_aux+0x11a/0x130
> [<ffffffff812127a8>] rb_free_aux+0x18/0x20
> [<ffffffff81212913>] perf_aux_output_begin+0x163/0x1e0
> [<ffffffff8100c33a>] bts_event_start+0x3a/0xd0
> [<ffffffff8100c42d>] bts_event_add+0x5d/0x80
> [<ffffffff81203646>] event_sched_in.isra.104+0xf6/0x2f0
> [<ffffffff8120652e>] group_sched_in+0x6e/0x190
> [<ffffffff8120694e>] ctx_sched_in+0x2fe/0x5f0
> [<ffffffff81206ca0>] perf_event_sched_in+0x60/0x80
> [<ffffffff81206d1b>] ctx_resched+0x5b/0x90
> [<ffffffff81207281>] __perf_event_enable+0x1e1/0x240
> [<ffffffff81200639>] event_function+0xa9/0x180
> [<ffffffff81202000>] ? perf_cgroup_attach+0x70/0x70
> [<ffffffff8120203f>] remote_function+0x3f/0x50
> [<ffffffff811971f3>] flush_smp_call_function_queue+0x83/0x150
> [<ffffffff81197bd3>] generic_smp_call_function_single_interrupt+0x13/0x60
> [<ffffffff810a6477>] smp_call_function_single_interrupt+0x27/0x40
> [<ffffffff81a26ea9>] call_function_single_interrupt+0x89/0x90
> [<ffffffff81120056>] finish_task_switch+0xa6/0x210
> [<ffffffff81120017>] ? finish_task_switch+0x67/0x210
> [<ffffffff81a1e83d>] __schedule+0x3dd/0xb50
> [<ffffffff81a1efe5>] schedule+0x35/0x80
> [<ffffffff81128031>] sys_sched_yield+0x61/0x70
> [<ffffffff81a25be5>] entry_SYSCALL_64_fastpath+0x18/0xa8
> ---[ end trace 6235f556f5ea83a9 ]---
This patch puts the checks in perf_aux_output_begin() in the same order
as that of perf_mmap_close().
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160906132353.19887-3-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In the mmap_close() path we need to stop all the AUX events that are
writing data to the AUX area that we are unmapping, before we can
safely free the pages. To determine if an event needs to be stopped,
we're comparing its ->rb against the one that's getting unmapped.
However, a SET_OUTPUT ioctl may turn up inside an AUX transaction
and swizzle event::rb to some other ring buffer, but the transaction
will keep writing data to the old ring buffer until the event gets
scheduled out. At this point, mmap_close() will skip over such an
event and will proceed to free the AUX area, while it's still being
used by this event, which will set off a warning in the mmap_close()
path and cause a memory corruption.
To avoid this, always stop an AUX event before its ->rb is updated;
this will release the (potentially) last reference on the AUX area
of the buffer. If the event gets restarted, its new ring buffer will
be used. If another SET_OUTPUT comes and switches it back to the
old ring buffer that's getting unmapped, it's also fine: this
ring buffer's aux_mmap_count will be zero and AUX transactions won't
start any more.
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160906132353.19887-2-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
track_pfn_insert() in vmf_insert_pfn_pmd() is marking dax mappings as
uncacheable rendering them impractical for application usage. DAX-pte
mappings are cached and the goal of establishing DAX-pmd mappings is to
attain more performance, not dramatically less (3 orders of magnitude).
track_pfn_insert() relies on a previous call to reserve_memtype() to
establish the expected page_cache_mode for the range. While memremap()
arranges for reserve_memtype() to be called, devm_memremap_pages() does
not. So, teach track_pfn_insert() and untrack_pfn() how to handle
tracking without a vma, and arrange for devm_memremap_pages() to
establish the write-back-cache reservation in the memtype tree.
Cc: <stable@vger.kernel.org>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Nilesh Choudhury <nilesh.choudhury@oracle.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Toshi Kani <toshi.kani@hpe.com>
Reported-by: Kai Zhang <kai.ka.zhang@oracle.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
