Commit Graph

21091 Commits

Author SHA1 Message Date
Linus Torvalds
df55793680 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
 "Misc fixes all around the map: an instrumentation fix, a nohz
  usability fix, a lockdep annotation fix and two task group scheduling
  fixes"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/core: Add missing lockdep_unpin() annotations
  sched/deadline: Fix migration of SCHED_DEADLINE tasks
  nohz: Revert "nohz: Set isolcpus when nohz_full is set"
  sched/fair: Update task group's load_avg after task migration
  sched/fair: Fix overly small weight for interactive group entities
  sched, tracing: Stop/start critical timings around the idle=poll idle loop
2015-10-23 22:31:39 +09:00
Linus Torvalds
9f30931a54 Merge branch 'akpm' (patches from Andrew)
Merge fixes from Andrew Morton:
 "9 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  ocfs2/dlm: unlock lockres spinlock before dlm_lockres_put
  fault-inject: fix inverted interval/probability values in printk
  lib/Kconfig.debug: disable -Wframe-larger-than warnings with KASAN=y
  mm: make sendfile(2) killable
  thp: use is_zero_pfn() only after pte_present() check
  mailmap: update Javier Martinez Canillas' email
  MAINTAINERS: add Sergey as zsmalloc reviewer
  mm: cma: fix incorrect type conversion for size during dma allocation
  kmod: don't run async usermode helper as a child of kworker thread
2015-10-23 22:10:51 +09:00
Peter Zijlstra
0aaafaabfc sched/core: Add missing lockdep_unpin() annotations
Luca and Wanpeng reported two missing annotations that led to
false lockdep complaints. Add the missing annotations.

Reported-by: Luca Abeni <luca.abeni@unitn.it>
Reported-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: cbce1a6867 ("sched,lockdep: Employ lock pinning")
Link: http://lkml.kernel.org/r/20151023095008.GY17308@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-23 12:02:10 +02:00
Oleg Nesterov
5211613978 kmod: don't run async usermode helper as a child of kworker thread
call_usermodehelper_exec_sync() does fork() + wait() with "unignored"
SIGCHLD.  What we have missed is that this worker thread can have other
children previously forked by call_usermodehelper_exec_work() without
UMH_WAIT_PROC.  If such a child exits in between it becomes a zombie
because auto-reaping only works if SIGCHLD is ignored, and nobody can
reap it (unless/until this worker thread exits too).

Change the !UMH_WAIT_PROC case to use CLONE_PARENT.

Note: this is only first step.  All PF_KTHREAD tasks, even created by
kernel_thread() should have ->parent == kthreadd by default.

Fixes: bb304a5c6f ("kmod: handle UMH_WAIT_PROC from system unbound workqueue")
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-23 17:55:10 +09:00
Steven Rostedt (Red Hat)
1904be1b6b tracing: Do not allow stack_tracer to record stack in NMI
The code in stack tracer should not be executed within an NMI as it grabs
spinlocks and stack tracing an NMI gives the possibility of causing a
deadlock. Although this is safe on x86_64, because it does not perform stack
traces when the task struct stack is not in use (interrupts and NMIs), it
may be an issue for NMIs on i386 and other archs that use the same stack as
the NMI.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-10-20 21:52:23 -04:00
Steven Rostedt (Red Hat)
a2d7629048 tracing: Have stack tracer force RCU to be watching
The stack tracer was triggering the WARN_ON() in module.c:

 static void module_assert_mutex_or_preempt(void)
 {
 #ifdef CONFIG_LOCKDEP
	if (unlikely(!debug_locks))
		return;

	WARN_ON(!rcu_read_lock_sched_held() &&
		!lockdep_is_held(&module_mutex));
 #endif
 }

The reason is that the stack tracer traces all function calls, and some of
those calls happen while exiting or entering user space and idle. Some of
these functions are called after RCU had already stopped watching, as RCU
does not watch userspace or idle CPUs.

If a max stack is hit, then the save_stack_trace() is called, which will
check module addresses and call module_assert_mutex_or_preempt(), and then
trigger the warning. Sad part is, the warning itself will also do a stack
trace and tigger the same warning. That probably should be fixed.

The warning was added by 0be964be0d "module: Sanitize RCU usage and
locking" but this bug has probably been around longer. But it's unlikely to
cause much harm, but the new warning causes the system to lock up.

Cc: stable@vger.kernel.org # 4.2+
Cc: Peter Zijlstra <peterz@infradead.org>
Cc:"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-10-20 11:38:08 -04:00
Luca Abeni
5aa5050787 sched/deadline: Fix migration of SCHED_DEADLINE tasks
Commit:

  9d51426242 ("sched/deadline: Reduce rq lock contention by eliminating locking of non-feasible target")

broke select_task_rq_dl() and find_lock_later_rq(), because it introduced
a comparison between the local task's deadline and dl.earliest_dl.curr of
the remote queue.

However, if the remote runqueue does not contain any SCHED_DEADLINE
task its earliest_dl.curr is 0 (always smaller than the deadline of
the local task) and the remote runqueue is not selected for pushing.

As a result, if an application creates multiple SCHED_DEADLINE
threads, they will never be pushed to runqueues that do not already
contain SCHED_DEADLINE tasks.

This patch fixes the issue by checking if dl.dl_nr_running == 0.

Signed-off-by: Luca Abeni <luca.abeni@unitn.it>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wanpeng Li <wanpeng.li@linux.intel.com>
Fixes: 9d51426242 ("sched/deadline: Reduce rq lock contention by eliminating locking of non-feasible target")
Link: http://lkml.kernel.org/r/1444982781-15608-1-git-send-email-luca.abeni@unitn.it
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-20 10:13:36 +02:00
Frederic Weisbecker
0baabb385e nohz: Revert "nohz: Set isolcpus when nohz_full is set"
This reverts:

  8cb9764fc8 ("nohz: Set isolcpus when nohz_full is set")

We assumed that full-nohz users always want scheduler isolation on full
dynticks CPUs, therefore we included full-nohz CPUs on cpu_isolated_map.

This means that tasks run by default on CPUs outside the nohz_full range
unless their affinity is explicity overwritten.

This suits pure isolation workloads but when the machine is needed to
run common workloads, the available sets of CPUs to run common tasks
becomes reduced.

We reach an extreme case when CONFIG_NO_HZ_FULL_ALL is enabled as it
leaves only CPU 0 for non-isolation tasks, which makes people think that
their supercomputer regressed to 90's UP - which is true in a sense.

Some full-nohz users appear to be interested in running normal workloads
either before or after an isolation workload. Full-nohz isn't optimized
toward normal workloads but it's still better than UP performance.

We are reaching a limitation in kernel presets here. Lets revert this
cpu_isolated_map inclusion and let userspace do its own scheduler
isolation using cpusets or explicit affinity settings.

Reported-by: Ingo Molnar <mingo@kernel.org>
Reported-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E . McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Link: http://lkml.kernel.org/r/1444663283-30068-1-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-20 10:13:36 +02:00
Yuyang Du
3e386d56ba sched/fair: Update task group's load_avg after task migration
When cfs_rq has cfs_rq->removed_load_avg set (when a task migrates from
this cfs_rq), we need to update its contribution to the group's load_avg.

This should not increase tg's update too much, because in most cases, the
cfs_rq has already decayed its load_avg.

Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Yuyang Du <yuyang.du@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1444699103-20272-2-git-send-email-yuyang.du@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-20 10:13:35 +02:00
Yuyang Du
fde7d22e01 sched/fair: Fix overly small weight for interactive group entities
Commit:

  9d89c257df ("sched/fair: Rewrite runnable load and utilization average tracking")

led to an overly small weight for interactive group entities. The bad case
can be easily reproduced when a number of CPU hogs compete for the CPUs
at the same time (thanks to Mike). This is largly because the task group's
load average tracking cross CPUs lags behind the real changes.

To fix this we accelerate the group share distribution process by using
the load.weight of the cfs_rq. This may increase the entire group's
share, but we have to do so to protect the (fragile) interactive
tasks, especially from CPU hogs.

Reported-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Tested-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Signed-off-by: Yuyang Du <yuyang.du@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1444699103-20272-1-git-send-email-yuyang.du@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-20 10:13:34 +02:00
Linus Torvalds
81429a6dbc Merge branches 'irq-urgent-for-linus' and 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq/timer fixes from Thomas Gleixner:
 "irq: a fix for the new hierarchical MSI interrupt handling which
  unbreaks PCI=n configurations.

  timers: a fix for the new hrtimer clock offset update mechanism to
  ensure that the boot time offset is respected"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq/msi: Do not use pci_msi_[un]mask_irq as default methods

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timekeeping: Increment clock_was_set_seq in timekeeping_init()
2015-10-17 08:47:27 -07:00
Thomas Gleixner
56fd16caba timekeeping: Increment clock_was_set_seq in timekeeping_init()
timekeeping_init() can set the wall time offset, so we need to
increment the clock_was_set_seq counter. That way hrtimers will pick
up the early offset immediately. Otherwise on a machine which does not
set wall time later in the boot process the hrtimer offset is stale at
0 and wall time timers are going to expire with a delay of 45 years.

Fixes: 868a3e915f "hrtimer: Make offset update smarter"
Reported-and-tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Stefan Liebler <stli@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
2015-10-16 15:50:22 +02:00
Marc Zyngier
0701c53e46 genirq/msi: Do not use pci_msi_[un]mask_irq as default methods
When we create a generic MSI domain, that MSI_FLAG_USE_DEF_CHIP_OPS
is set, and that any of .mask or .unmask are NULL in the irq_chip
structure, we set them to pci_msi_[un]mask_irq.

This is a bad idea for at least two reasons:
- PCI_MSI might not be selected, kernel fails to build (yes, this is
  legitimate, at least on arm64!)
- This may not be a PCI/MSI domain at all (platform MSI, for example)

Either way, this looks wrong. Move the overriding of mask/unmask to
the PCI counterpart, and panic is any of these two methods is not
set in the core code (they really should be present).

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Link: http://lkml.kernel.org/r/1444760085-27857-1-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-10-16 12:40:43 +02:00
Linus Torvalds
995e2fe9a4 Merge branch 'for-4.3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue fixlet from Tejun Heo:
 "Single patch to make delayed work always be queued on the local CPU"

This is not actually something we should guarantee, but it's something
we by accident have historically done, and at least one call site has
grown to depend on it.

I'm going to fix that known broken callsite, but in the meantime this
makes the accidental behavior be explicit, just in case there are other
cases that might depend on it.

* 'for-4.3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: make sure delayed work run in local cpu
2015-10-15 12:58:37 -07:00
Daniel Bristot de Oliveira
9babcd7929 sched, tracing: Stop/start critical timings around the idle=poll idle loop
When using idle=poll, the preemptoff tracer is always showing
the idle task as the culprit for long latencies. That happens
because critical timings are not stopped before idle loop. This
patch stops critical timings before entering the idle loop,
starting it again after the idle loop.

This problem does not affect the irqsoff tracer because
interruptions are enabled before entering the idle loop.

Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Reviewed-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/10fc3705874aef11dbe152a068b591a7be1899b4.1444314899.git.bristot@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-12 09:45:25 +02:00
Linus Torvalds
9a78f9c3c6 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fix from Thomas Gleixner:
 "Fix a long standing state race in finish_task_switch()"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/core: Fix TASK_DEAD race in finish_task_switch()
2015-10-11 10:24:32 -07:00
Arnd Bergmann
e3096c9c7c genirq: Fix handle_bad_irq kerneldoc comment
A recent cleanup removed the 'irq' parameter from many functions, but
left the documentation for this in place for at least one function.

This removes it.

Fixes: bd0b9ac405 ("genirq: Remove irq argument from irq flow handlers")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: kbuild-all@01.org
Cc: Austin Schuh <austin@peloton-tech.com>
Cc: Santosh Shilimkar <ssantosh@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/5400000.cD19rmgWjV@wuerfel
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-10-09 17:17:30 +02:00
Arnd Bergmann
9d67dc5da5 genirq: Export handle_bad_irq
A cleanup of the omap gpio driver introduced a use of the
handle_bad_irq() function in a device driver that can be
a loadable module.

This broke the ARM allmodconfig build:

ERROR: "handle_bad_irq" [drivers/gpio/gpio-omap.ko] undefined!

This patch exports the handle_bad_irq symbol in order to
allow the use in modules.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Santosh Shilimkar <ssantosh@kernel.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Austin Schuh <austin@peloton-tech.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/5847725.4IBopItaOr@wuerfel
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-10-09 17:17:30 +02:00
Peter Zijlstra
95913d9791 sched/core: Fix TASK_DEAD race in finish_task_switch()
So the problem this patch is trying to address is as follows:

        CPU0                            CPU1

        context_switch(A, B)
                                        ttwu(A)
                                          LOCK A->pi_lock
                                          A->on_cpu == 0
        finish_task_switch(A)
          prev_state = A->state  <-.
          WMB                      |
          A->on_cpu = 0;           |
          UNLOCK rq0->lock         |
                                   |    context_switch(C, A)
                                   `--  A->state = TASK_DEAD
          prev_state == TASK_DEAD
            put_task_struct(A)
                                        context_switch(A, C)
                                        finish_task_switch(A)
                                          A->state == TASK_DEAD
                                            put_task_struct(A)

The argument being that the WMB will allow the load of A->state on CPU0
to cross over and observe CPU1's store of A->state, which will then
result in a double-drop and use-after-free.

Now the comment states (and this was true once upon a long time ago)
that we need to observe A->state while holding rq->lock because that
will order us against the wakeup; however the wakeup will not in fact
acquire (that) rq->lock; it takes A->pi_lock these days.

We can obviously fix this by upgrading the WMB to an MB, but that is
expensive, so we'd rather avoid that.

The alternative this patch takes is: smp_store_release(&A->on_cpu, 0),
which avoids the MB on some archs, but not important ones like ARM.

Reported-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: <stable@vger.kernel.org> # v3.1+
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Cc: manfred@colorfullife.com
Cc: will.deacon@arm.com
Fixes: e4a52bcb9a ("sched: Remove rq->lock from the first half of ttwu()")
Link: http://lkml.kernel.org/r/20150929124509.GG3816@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-06 17:05:17 +02:00
Linus Torvalds
3e519dde1e Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Thomas Gleixner:
 "This update contains:

   - Fix for a long standing race affecting /proc/irq/NNN

   - One line fix for ARM GICV3-ITS counting the wrong data

   - Warning silencing in ARM GICV3-ITS.  Another GCC trying to be
     overly clever issue"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/gic-v3-its: Count additional LPIs for the aliased devices
  irqchip/gic-v3-its: Silence warning when its_lpi_alloc_chunks gets inlined
  genirq: Fix race in register_irq_proc()
2015-10-04 11:40:09 +01:00
Linus Torvalds
37cc7ab1d2 Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Ingo Molnar:
 "An abs64() fix in the watchdog driver, and two clocksource driver
  NO_IRQ assumption fixes"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource: Fix abs() usage w/ 64bit values
  clocksource/drivers/keystone: Fix bad NO_IRQ usage
  clocksource/drivers/rockchip: Fix bad NO_IRQ usage
2015-10-03 10:51:41 -04:00
John Stultz
67dfae0cd7 clocksource: Fix abs() usage w/ 64bit values
This patch fixes one cases where abs() was being used with 64-bit
nanosecond values, where the result may be capped at 32-bits.

This potentially could cause watchdog false negatives on 32-bit
systems, so this patch addresses the issue by using abs64().

Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1442279124-7309-2-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-10-02 22:53:01 +02:00
Ben Hutchings
95c2b17534 genirq: Fix race in register_irq_proc()
Per-IRQ directories in procfs are created only when a handler is first
added to the irqdesc, not when the irqdesc is created.  In the case of
a shared IRQ, multiple tasks can race to create a directory.  This
race condition seems to have been present forever, but is easier to
hit with async probing.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Link: http://lkml.kernel.org/r/1443266636.2004.2.camel@decadent.org.uk
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
2015-10-01 12:18:13 +02:00
Shaohua Li
874bbfe600 workqueue: make sure delayed work run in local cpu
My system keeps crashing with below message. vmstat_update() schedules a delayed
work in current cpu and expects the work runs in the cpu.
schedule_delayed_work() is expected to make delayed work run in local cpu. The
problem is timer can be migrated with NO_HZ. __queue_work() queues work in
timer handler, which could run in a different cpu other than where the delayed
work is scheduled. The end result is the delayed work runs in different cpu.
The patch makes __queue_delayed_work records local cpu earlier. Where the timer
runs doesn't change where the work runs with the change.

[   28.010131] ------------[ cut here ]------------
[   28.010609] kernel BUG at ../mm/vmstat.c:1392!
[   28.011099] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC KASAN
[   28.011860] Modules linked in:
[   28.012245] CPU: 0 PID: 289 Comm: kworker/0:3 Tainted: G        W4.3.0-rc3+ #634
[   28.013065] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140709_153802- 04/01/2014
[   28.014160] Workqueue: events vmstat_update
[   28.014571] task: ffff880117682580 ti: ffff8800ba428000 task.ti: ffff8800ba428000
[   28.015445] RIP: 0010:[<ffffffff8115f921>]  [<ffffffff8115f921>]vmstat_update+0x31/0x80
[   28.016282] RSP: 0018:ffff8800ba42fd80  EFLAGS: 00010297
[   28.016812] RAX: 0000000000000000 RBX: ffff88011a858dc0 RCX:0000000000000000
[   28.017585] RDX: ffff880117682580 RSI: ffffffff81f14d8c RDI:ffffffff81f4df8d
[   28.018366] RBP: ffff8800ba42fd90 R08: 0000000000000001 R09:0000000000000000
[   28.019169] R10: 0000000000000000 R11: 0000000000000121 R12:ffff8800baa9f640
[   28.019947] R13: ffff88011a81e340 R14: ffff88011a823700 R15:0000000000000000
[   28.020071] FS:  0000000000000000(0000) GS:ffff88011a800000(0000)knlGS:0000000000000000
[   28.020071] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[   28.020071] CR2: 00007ff6144b01d0 CR3: 00000000b8e93000 CR4:00000000000006f0
[   28.020071] Stack:
[   28.020071]  ffff88011a858dc0 ffff8800baa9f640 ffff8800ba42fe00ffffffff8106bd88
[   28.020071]  ffffffff8106bd0b 0000000000000096 0000000000000000ffffffff82f9b1e8
[   28.020071]  ffffffff829f0b10 0000000000000000 ffffffff81f18460ffff88011a81e340
[   28.020071] Call Trace:
[   28.020071]  [<ffffffff8106bd88>] process_one_work+0x1c8/0x540
[   28.020071]  [<ffffffff8106bd0b>] ? process_one_work+0x14b/0x540
[   28.020071]  [<ffffffff8106c214>] worker_thread+0x114/0x460
[   28.020071]  [<ffffffff8106c100>] ? process_one_work+0x540/0x540
[   28.020071]  [<ffffffff81071bf8>] kthread+0xf8/0x110
[   28.020071]  [<ffffffff81071b00>] ?kthread_create_on_node+0x200/0x200
[   28.020071]  [<ffffffff81a6522f>] ret_from_fork+0x3f/0x70
[   28.020071]  [<ffffffff81071b00>] ?kthread_create_on_node+0x200/0x200

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org # v2.6.31+
2015-09-30 13:06:46 -04:00
Linus Torvalds
70c8a00a09 Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU fixes from Ingo Molnar:
 "Two RCU fixes:

   - work around bug with recent GCC versions.

   - fix false positive lockdep splat"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rcu: Suppress lockdep false positive for rcp->exp_funnel_mutex
  rcu: Change _wait_rcu_gp() to work around GCC bug 67055
2015-09-30 13:01:35 -04:00
Ingo Molnar
7c4f1c694b Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/urgent
Pull RCU fixes from Paul E. McKenney, for two regressions
introduced in this merge window:

  - Fix bug with recent GCCs.
  - Fix false positive lockdep splat.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-28 08:03:52 +02:00
Linus Torvalds
e3be4266d3 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner:
 "Another pile of fixes for perf:

   - Plug overflows and races in the core code

   - Sanitize the flow of the perf syscall so we error out before
     handling the more complex and hard to undo setups

   - Improve and fix Broadwell and Skylake hardware support

   - Revert a fix which broke what it tried to fix in perf tools

   - A couple of smaller fixes in various places of perf tools"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf tools: Fix copying of /proc/kcore
  perf intel-pt: Remove no_force_psb from documentation
  perf probe: Use existing routine to look for a kernel module by dso->short_name
  perf/x86: Change test_aperfmperf() and test_intel() to static
  tools lib traceevent: Fix string handling in heterogeneous arch environments
  perf record: Avoid infinite loop at buildid processing with no samples
  perf: Fix races in computing the header sizes
  perf: Fix u16 overflows
  perf: Restructure perf syscall point of no return
  perf/x86/intel: Fix Skylake FRONTEND MSR extrareg mask
  perf/x86/intel/pebs: Add PEBS frontend profiling for Skylake
  perf/x86/intel: Make the CYCLE_ACTIVITY.* constraint on Broadwell more specific
  perf tools: Bool functions shouldn't return -1
  tools build: Add test for presence of __get_cpuid() gcc builtin
  tools build: Add test for presence of numa_num_possible_cpus() in libnuma
  Revert "perf symbols: Fix mismatched declarations for elf_getphdrnum"
  perf stat: Fix per-pkg event reporting bug
2015-09-27 12:51:39 -04:00
Linus Torvalds
73f479b243 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fix from Thomas Gleixner:
 "A single bug fix for the scheduler to prevent dequeueing of the idle
  task when setting the cpus allowed mask"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Fix crash trying to dequeue/enqueue the idle thread
2015-09-27 12:50:27 -04:00
Linus Torvalds
fc11a9c5da Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fix from Thomas Gleixner:
 "A single bugfix for lockdep to preserve the pinning counter when
  rebuilding the lock stack"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/lockdep: Fix hlock->pin_count reset on lock stack rebuilds
2015-09-27 12:47:20 -04:00
Peter Zijlstra
21199f27b4 locking/lockdep: Fix hlock->pin_count reset on lock stack rebuilds
Various people reported hitting the "unpinning an unpinned lock"
warning. As it turns out there are 2 places where we take a lock out
of the middle of a stack, and in those cases it would fail to preserve
the pin_count when rebuilding the lock stack.

Reported-by: Sasha Levin <sasha.levin@oracle.com>
Reported-by: Tim Spriggs <tspriggs@apple.com>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: davej@codemonkey.org.uk
Link: http://lkml.kernel.org/r/20150916141040.GA11639@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-23 09:48:53 +02:00
Andrea Arcangeli
ac5be6b47e userfaultfd: revert "userfaultfd: waitqueue: add nr wake parameter to __wake_up_locked_key"
This reverts commit 51360155ec and adapts
fs/userfaultfd.c to use the old version of that function.

It didn't look robust to call __wake_up_common with "nr == 1" when we
absolutely require wakeall semantics, but we've full control of what we
insert in the two waitqueue heads of the blocked userfaults.  No
exclusive waitqueue risks to be inserted into those two waitqueue heads
so we can as well stick to "nr == 1" of the old code and we can rely
purely on the fact no waitqueue inserted in one of the two waitqueue
heads we must enforce as wakeall, has wait->flags WQ_FLAG_EXCLUSIVE set.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Thierry Reding <treding@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-22 15:09:53 -07:00
Linus Torvalds
bcee19f424 Merge branch 'for-4.3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
 "The threadgroup locking changes which went in during 4.2 devel cycle
  added write locking of a percpu_rwsem in cgroup task migration path;
  unfortunately, that involved expedited rcu syncing which turned out to
  be too slow and heavy for certain workloads.  The patchset which is
  dependent on this one didn't get committed during that devel cycle, so
  these two patches can be reverted safely.

  Oleg reworked percpu_rwsem for 4.4 so that the writer path is a lot
  lighter.  The reported issue goes away with Oleg's reworked
  percpu_rwsem and I'll reapply these patches on the for-4.4 branch so
  that they can land together with Oleg's changes"

* 'for-4.3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  Revert "sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem"
  Revert "cgroup: simplify threadgroup locking"
2015-09-21 18:26:54 -07:00
Paul E. McKenney
19a5ecde08 rcu: Suppress lockdep false positive for rcp->exp_funnel_mutex
In kernels built with CONFIG_PREEMPT=y, synchronize_rcu_expedited()
invokes synchronize_sched_expedited() while holding RCU-preempt's
root rcu_node structure's ->exp_funnel_mutex, which is acquired after
the rcu_data structure's ->exp_funnel_mutex.  The first thing that
synchronize_sched_expedited() will do is acquire RCU-sched's rcu_data
structure's ->exp_funnel_mutex.   There is no danger of an actual deadlock
because the locking order is always from RCU-preempt's expedited mutexes
to those of RCU-sched.  Unfortunately, lockdep considers both rcu_data
structures' ->exp_funnel_mutex to be in the same lock class and therefore
reports a deadlock cycle.

This commit silences this false positive by placing RCU-sched's rcu_data
structures' ->exp_funnel_mutex locks into their own lock class.

Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-09-20 21:01:22 -07:00
Linus Torvalds
3ae839454e Mostly stable material, a lot of ARM fixes.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM fixes from Paolo Bonzini:
 "Mostly stable material, a lot of ARM fixes"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (22 commits)
  sched: access local runqueue directly in single_task_running
  arm/arm64: KVM: Remove 'config KVM_ARM_MAX_VCPUS'
  arm64: KVM: Remove all traces of the ThumbEE registers
  arm: KVM: Disable virtual timer even if the guest is not using it
  arm64: KVM: Disable virtual timer even if the guest is not using it
  arm/arm64: KVM: vgic: Check for !irqchip_in_kernel() when mapping resources
  KVM: s390: Replace incorrect atomic_or with atomic_andnot
  arm: KVM: Fix incorrect device to IPA mapping
  arm64: KVM: Fix user access for debug registers
  KVM: vmx: fix VPID is 0000H in non-root operation
  KVM: add halt_attempted_poll to VCPU stats
  kvm: fix zero length mmio searching
  kvm: fix double free for fast mmio eventfd
  kvm: factor out core eventfd assign/deassign logic
  kvm: don't try to register to KVM_FAST_MMIO_BUS for non mmio eventfd
  KVM: make the declaration of functions within 80 characters
  KVM: arm64: add workaround for Cortex-A57 erratum #852523
  KVM: fix polling for guest halt continued even if disable it
  arm/arm64: KVM: Fix PSCI affinity info return value for non valid cores
  arm64: KVM: set {v,}TCR_EL2 RES1 bits
  ...
2015-09-18 09:23:08 -07:00
Linus Torvalds
fadb97b089 Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq updates from Thomas Gleixner:
 "This is a rather large update post rc1 due to the final steps of
  cleanups and API changes which had to wait for the preparatory patches
  to hit your tree.

   - Regression fixes for ARM GIC irqchips

   - Regression fixes and lockdep anotations for renesas irq chips

   - The leftovers of the cleanup and preparatory patches which have
     been ignored by maintainers

   - Final conversions of the newly merged users of obsolete APIs

   - Final removal of obsolete APIs

   - Final removal of ARM artifacts which had been introduced during the
     conversion of ARM to the generic interrupt code.

   - Final split of the irq_data into chip specific and common data to
     reflect the needs of hierarchical irq domains.

   - Treewide removal of the first argument of interrupt flow handlers,
     i.e. the irq number, which is not used by the majority of handlers
     and simple to retrieve from the other argument the irq descriptor.

   - A few comment updates and build warning fixes"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
  arm64: Remove ununsed set_irq_flags
  ARM: Remove ununsed set_irq_flags
  sh: Kill off set_irq_flags usage
  irqchip: Kill off set_irq_flags usage
  gpu/drm: Kill off set_irq_flags usage
  genirq: Remove irq argument from irq flow handlers
  genirq: Move field 'msi_desc' from irq_data into irq_common_data
  genirq: Move field 'affinity' from irq_data into irq_common_data
  genirq: Move field 'handler_data' from irq_data into irq_common_data
  genirq: Move field 'node' from irq_data into irq_common_data
  irqchip/gic-v3: Use IRQD_FORWARDED_TO_VCPU flag
  irqchip/gic: Use IRQD_FORWARDED_TO_VCPU flag
  genirq: Provide IRQD_FORWARDED_TO_VCPU status flag
  genirq: Simplify irq_data_to_desc()
  genirq: Remove __irq_set_handler_locked()
  pinctrl/pistachio: Use irq_set_handler_locked
  gpio: vf610: Use irq_set_handler_locked
  powerpc/mpc8xx: Use irq_set_handler_locked()
  powerpc/ipic: Use irq_set_handler_locked()
  powerpc/cpm2: Use irq_set_handler_locked()
  ...
2015-09-18 08:11:42 -07:00
Dominik Dingel
00cc163381 sched: access local runqueue directly in single_task_running
Commit 2ee507c472 ("sched: Add function single_task_running to let a task
check if it is the only task running on a cpu") referenced the current
runqueue with the smp_processor_id.  When CONFIG_DEBUG_PREEMPT is enabled,
that is only allowed if preemption is disabled or the currrent task is
bound to the local cpu (e.g. kernel worker).

With commit f781951299 ("kvm: add halt_poll_ns module parameter") KVM
calls single_task_running. If CONFIG_DEBUG_PREEMPT is enabled that
generates a lot of kernel messages.

To avoid adding preemption in that cases, as it would limit the usefulness,
we change single_task_running to access directly the cpu local runqueue.

Cc: Tim Chen <tim.c.chen@linux.intel.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Fixes: 2ee507c472
Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-09-18 13:47:59 +02:00
Peter Zijlstra
f73e22ab45 perf: Fix races in computing the header sizes
There are two races with the current code:

 - Another event can join the group and compute a larger header_size
   concurrently, if the smaller store wins we'll have an incorrect
   header_size set.

 - We compute the header_size after the event becomes active,
   therefore its possible to use the size before its computed.

Remedy the first by moving the computation inside the ctx::mutex lock,
and the second by placing it _before_ perf_install_in_context().

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.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>
2015-09-18 09:20:26 +02:00
Peter Zijlstra
a723968c0e perf: Fix u16 overflows
Vince reported that its possible to overflow the various size fields
and get weird stuff if you stick too many events in a group.

Put a lid on this by requiring the fixed record size not exceed 16k.
This is still a fair amount of events (silly amount really) and leaves
plenty room for callchains and stack dwarves while also avoiding
overflowing the u16 variables.

Reported-by: Vince Weaver <vincent.weaver@maine.edu>
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>
2015-09-18 09:20:25 +02:00
Peter Zijlstra
f55fc2a57c perf: Restructure perf syscall point of no return
The exclusive_event_installable() stuff only works because its
exclusive with the grouping bits.

Rework the code such that there is a sane place to error out before we
go do things we cannot undo.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
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>
2015-09-18 09:20:24 +02:00
Peter Zijlstra
de9b8f5dcb sched: Fix crash trying to dequeue/enqueue the idle thread
Sasha reports that his virtual machine tries to schedule the idle
thread since commit 6c37067e27 ("sched: Change the
sched_class::set_cpus_allowed() calling context").

Hit trace shows this happening from idle_thread_get()->init_idle(),
which is the _second_ init_idle() invocation on that task_struct, the
first being done through idle_init()->fork_idle(). (this code is
insane...)

Because we call init_idle() twice in a row, its ->sched_class ==
&idle_sched_class and ->on_rq = TASK_ON_RQ_QUEUED. This means
do_set_cpus_allowed() think we're queued and will call dequeue_task(),
which is implemented with BUG() for the idle class, seeing how
dequeueing the idle task is a daft thing.

Aside of the whole insanity of calling init_idle() _twice_, change the
code to call set_cpus_allowed_common() instead as this is 'obviously'
before the idle task gets ran etc..

Reported-by: Sasha Levin <sasha.levin@oracle.com>
Tested-by: Sasha Levin <sasha.levin@oracle.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>
Fixes: 6c37067e27 ("sched: Change the sched_class::set_cpus_allowed() calling context")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-18 09:17:50 +02:00
Linus Torvalds
1345df21ac Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Ingo Molnar:
 "A fix for an abs()/abs64() bug that caused too slow NTP convergence on
  32-bit kernels, plus a removal of an obsolete clockevents driver
  facility after all users got converted during the merge window"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clockevents: Remove unused set_mode() callback
  time: Fix timekeeping_freqadjust()'s incorrect use of abs() instead of abs64()
2015-09-17 10:55:25 -07:00
Linus Torvalds
c2ea72fd86 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
 "A migrate_tasks() locking fix, and a late-coming nohz change plus a
  nohz debug check"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: 'Annotate' migrate_tasks()
  nohz: Assert existing housekeepers when nohz full enabled
  nohz: Affine unpinned timers to housekeepers
2015-09-17 10:49:42 -07:00
Linus Torvalds
9786cff38a Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Ingo Molnar:
 "Spinlock performance regression fix, plus documentation fixes"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/static_keys: Fix up the static keys documentation
  locking/qspinlock/x86: Only emit the test-and-set fallback when building guest support
  locking/qspinlock/x86: Fix performance regression under unaccelerated VMs
  locking/static_keys: Fix a silly typo
2015-09-17 08:45:23 -07:00
Tejun Heo
0c986253b9 Revert "sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem"
This reverts commit d59cfc09c3.

d59cfc09c3 ("sched, cgroup: replace signal_struct->group_rwsem with
a global percpu_rwsem") and b5ba75b5fc ("cgroup: simplify
threadgroup locking") changed how cgroup synchronizes against task
fork and exits so that it uses global percpu_rwsem instead of
per-process rwsem; unfortunately, the write [un]lock paths of
percpu_rwsem always involve synchronize_rcu_expedited() which turned
out to be too expensive.

Improvements for percpu_rwsem are scheduled to be merged in the coming
v4.4-rc1 merge window which alleviates this issue.  For now, revert
the two commits to restore per-process rwsem.  They will be re-applied
for the v4.4-rc1 merge window.

Signed-off-by: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/g/55F8097A.7000206@de.ibm.com
Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: stable@vger.kernel.org # v4.2+
2015-09-16 11:51:12 -04:00
Tejun Heo
f9f9e7b776 Revert "cgroup: simplify threadgroup locking"
This reverts commit b5ba75b5fc.

d59cfc09c3 ("sched, cgroup: replace signal_struct->group_rwsem with
a global percpu_rwsem") and b5ba75b5fc ("cgroup: simplify
threadgroup locking") changed how cgroup synchronizes against task
fork and exits so that it uses global percpu_rwsem instead of
per-process rwsem; unfortunately, the write [un]lock paths of
percpu_rwsem always involve synchronize_rcu_expedited() which turned
out to be too expensive.

Improvements for percpu_rwsem are scheduled to be merged in the coming
v4.4-rc1 merge window which alleviates this issue.  For now, revert
the two commits to restore per-process rwsem.  They will be re-applied
for the v4.4-rc1 merge window.

Signed-off-by: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/g/55F8097A.7000206@de.ibm.com
Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: stable@vger.kernel.org # v4.2+
2015-09-16 11:51:12 -04:00
Thomas Gleixner
bd0b9ac405 genirq: Remove irq argument from irq flow handlers
Most interrupt flow handlers do not use the irq argument. Those few
which use it can retrieve the irq number from the irq descriptor.

Remove the argument.

Search and replace was done with coccinelle and some extra helper
scripts around it. Thanks to Julia for her help!

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
2015-09-16 15:47:51 +02:00
Jiang Liu
b237721c5d genirq: Move field 'msi_desc' from irq_data into irq_common_data
MSI descriptors are per-irq instead of per irqchip, so move it into
struct irq_common_data.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: http://lkml.kernel.org/r/1433145945-789-35-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-09-16 15:46:49 +02:00
Jiang Liu
9df872faa7 genirq: Move field 'affinity' from irq_data into irq_common_data
Irq affinity mask is per-irq instead of per irqchip, so move it into
struct irq_common_data.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Link: http://lkml.kernel.org/r/1433303281-27688-1-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-09-16 15:46:49 +02:00
Jiang Liu
af7080e040 genirq: Move field 'handler_data' from irq_data into irq_common_data
Handler data (handler_data) is per-irq instead of per irqchip, so move
it into struct irq_common_data.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: http://lkml.kernel.org/r/1433145945-789-13-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-09-16 15:46:49 +02:00
Jiang Liu
449e9cae58 genirq: Move field 'node' from irq_data into irq_common_data
NUMA node information is per-irq instead of per-irqchip, so move it into
struct irq_common_data. Also use CONFIG_NUMA to guard irq_common_data.node.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Link: http://lkml.kernel.org/r/1433145945-789-8-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-09-16 15:46:49 +02:00