linux.git/kernel/time, branch v3.18-rc2

Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu

2014-10-15T05:48:18+00:00

Pull percpu consistent-ops changes from Tejun Heo:
"Way back, before the current percpu allocator was implemented, static
and dynamic percpu memory areas were allocated and handled separately
and had their own accessors. The distinction has been gone for many
years now; however, the now duplicate two sets of accessors remained
with the pointer based ones - this_cpu_*() - evolving various other
operations over time. During the process, we also accumulated other
inconsistent operations.

This pull request contains Christoph's patches to clean up the
duplicate accessor situation. __get_cpu_var() uses are replaced with
with this_cpu_ptr() and __this_cpu_ptr() with raw_cpu_ptr().

Unfortunately, the former sometimes is tricky thanks to C being a bit
messy with the distinction between lvalues and pointers, which led to
a rather ugly solution for cpumask_var_t involving the introduction of
this_cpu_cpumask_var_ptr().

This converts most of the uses but not all. Christoph will follow up
with the remaining conversions in this merge window and hopefully
remove the obsolete accessors"

* 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (38 commits)
irqchip: Properly fetch the per cpu offset
percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t -fix
ia64: sn_nodepda cannot be assigned to after this_cpu conversion. Use __this_cpu_write.
percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t
Revert "powerpc: Replace __get_cpu_var uses"
percpu: Remove __this_cpu_ptr
clocksource: Replace __this_cpu_ptr with raw_cpu_ptr
sparc: Replace __get_cpu_var uses
avr32: Replace __get_cpu_var with __this_cpu_write
blackfin: Replace __get_cpu_var uses
tile: Use this_cpu_ptr() for hardware counters
tile: Replace __get_cpu_var uses
powerpc: Replace __get_cpu_var uses
alpha: Replace __get_cpu_var
ia64: Replace __get_cpu_var uses
s390: cio driver &__get_cpu_var replacements
s390: Replace __get_cpu_var uses
mips: Replace __get_cpu_var uses
MIPS: Replace __get_cpu_var uses in FPU emulator.
arm: Replace __this_cpu_ptr with raw_cpu_ptr
...

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2014-10-14T01:47:00+00:00

Pull s390 updates from Martin Schwidefsky:
 "This patch set contains the main portion of the changes for 3.18 in
  regard to the s390 architecture.  It is a bit bigger than usual,
  mainly because of a new driver and the vector extension patches.

  The interesting bits are:
   - Quite a bit of work on the tracing front.  Uprobes is enabled and
     the ftrace code is reworked to get some of the lost performance
     back if CONFIG_FTRACE is enabled.
   - To improve boot time with CONFIG_DEBIG_PAGEALLOC, support for the
     IPTE range facility is added.
   - The rwlock code is re-factored to improve writer fairness and to be
     able to use the interlocked-access instructions.
   - The kernel part for the support of the vector extension is added.
   - The device driver to access the CD/DVD on the HMC is added, this
     will hopefully come in handy to improve the installation process.
   - Add support for control-unit initiated reconfiguration.
   - The crypto device driver is enhanced to enable the additional AP
     domains and to allow the new crypto hardware to be used.
   - Bug fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (39 commits)
  s390/ftrace: simplify enabling/disabling of ftrace_graph_caller
  s390/ftrace: remove 31 bit ftrace support
  s390/kdump: add support for vector extension
  s390/disassembler: add vector instructions
  s390: add support for vector extension
  s390/zcrypt: Toleration of new crypto hardware
  s390/idle: consolidate idle functions and definitions
  s390/nohz: use a per-cpu flag for arch_needs_cpu
  s390/vtime: do not reset idle data on CPU hotplug
  s390/dasd: add support for control unit initiated reconfiguration
  s390/dasd: fix infinite loop during format
  s390/mm: make use of ipte range facility
  s390/setup: correct 4-level kernel page table detection
  s390/topology: call set_sched_topology early
  s390/uprobes: architecture backend for uprobes
  s390/uprobes: common library for kprobes and uprobes
  s390/rwlock: use the interlocked-access facility 1 instructions
  s390/rwlock: improve writer fairness
  s390/rwlock: remove interrupt-enabling rwlock variant.
  s390/mm: remove change bit override support
  ...

Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2014-10-13T14:23:15+00:00

Pull scheduler updates from Ingo Molnar:
 "The main changes in this cycle were:

   - Optimized support for Intel "Cluster-on-Die" (CoD) topologies (Dave
     Hansen)

   - Various sched/idle refinements for better idle handling (Nicolas
     Pitre, Daniel Lezcano, Chuansheng Liu, Vincent Guittot)

   - sched/numa updates and optimizations (Rik van Riel)

   - sysbench speedup (Vincent Guittot)

   - capacity calculation cleanups/refactoring (Vincent Guittot)

   - Various cleanups to thread group iteration (Oleg Nesterov)

   - Double-rq-lock removal optimization and various refactorings
     (Kirill Tkhai)

   - various sched/deadline fixes

  ... and lots of other changes"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (72 commits)
  sched/dl: Use dl_bw_of() under rcu_read_lock_sched()
  sched/fair: Delete resched_cpu() from idle_balance()
  sched, time: Fix build error with 64 bit cputime_t on 32 bit systems
  sched: Improve sysbench performance by fixing spurious active migration
  sched/x86: Fix up typo in topology detection
  x86, sched: Add new topology for multi-NUMA-node CPUs
  sched/rt: Use resched_curr() in task_tick_rt()
  sched: Use rq->rd in sched_setaffinity() under RCU read lock
  sched: cleanup: Rename 'out_unlock' to 'out_free_new_mask'
  sched: Use dl_bw_of() under RCU read lock
  sched/fair: Remove duplicate code from can_migrate_task()
  sched, mips, ia64: Remove __ARCH_WANT_UNLOCKED_CTXSW
  sched: print_rq(): Don't use tasklist_lock
  sched: normalize_rt_tasks(): Don't use _irqsave for tasklist_lock, use task_rq_lock()
  sched: Fix the task-group check in tg_has_rt_tasks()
  sched/fair: Leverage the idle state info when choosing the "idlest" cpu
  sched: Let the scheduler see CPU idle states
  sched/deadline: Fix inter- exclusive cpusets migrations
  sched/deadline: Clear dl_entity params when setscheduling to different class
  sched/numa: Kill the wrong/dead TASK_DEAD check in task_numa_fault()
  ...

Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2014-10-09T10:35:05+00:00

Pull timer updates from Thomas Gleixner:
 "Nothing really exciting this time:

   - a few fixlets in the NOHZ code

   - a new ARM SoC timer abomination.  One should expect that we have
     enough of them already, but they insist on inventing new ones.

   - the usual bunch of ARM SoC timer updates.  That feels like herding
     cats"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource: arm_arch_timer: Consolidate arch_timer_evtstrm_enable
  clocksource: arm_arch_timer: Enable counter access for 32-bit ARM
  clocksource: arm_arch_timer: Change clocksource name if CP15 unavailable
  clocksource: sirf: Disable counter before re-setting it
  clocksource: cadence_ttc: Add support for 32bit mode
  clocksource: tcb_clksrc: Sanitize IRQ request
  clocksource: arm_arch_timer: Discard unavailable timers correctly
  clocksource: vf_pit_timer: Support shutdown mode
  ARM: meson6: clocksource: Add Meson6 timer support
  ARM: meson: documentation: Add timer documentation
  clocksource: sh_tmu: Document r8a7779 binding
  clocksource: sh_mtu2: Document r7s72100 binding
  clocksource: sh_cmt: Document SoC specific bindings
  timerfd: Remove an always true check
  nohz: Avoid tick's double reprogramming in highres mode
  nohz: Fix spurious periodic tick behaviour in low-res dynticks mode

Merge branch 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2014-10-09T10:30:57+00:00

Pull timer fixes from Ingo Molnar:
 "Main changes:

  - Fix the deadlock reported by Dave Jones et al
  - Clean up and fix nohz_full interaction with arch abilities
  - nohz init code consolidation/cleanup"

* 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  nohz: nohz full depends on irq work self IPI support
  nohz: Consolidate nohz full init code
  arm64: Tell irq work about self IPI support
  arm: Tell irq work about self IPI support
  x86: Tell irq work about self IPI support
  irq_work: Force raised irq work to run on irq work interrupt
  irq_work: Introduce arch_irq_work_has_interrupt()
  nohz: Move nohz full init call to tick init

s390/nohz: use a per-cpu flag for arch_needs_cpu

2014-10-09T07:14:02+00:00

Move the nohz_delay bit from the s390_idle data structure to the
per-cpu flags. Clear the nohz delay flag in __cpu_disable and
remove the cpu hotplug notifier that used to do this.

Signed-off-by: Martin Schwidefsky

sched, cleanup, treewide: Remove set_current_state(TASK_RUNNING) after schedule()

2014-09-19T10:35:17+00:00

schedule(), io_schedule() and schedule_timeout() always return
with TASK_RUNNING state set, so one more setting is unnecessary.

(All places in patch are visible good, only exception is
 kiblnd_scheduler() from:

      drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c

 Its schedule() is one line above standard 3 lines of unified diff)

No places where set_current_state() is used for mb().

Signed-off-by: Kirill Tkhai 
Signed-off-by: Peter Zijlstra (Intel) 
Link: http://lkml.kernel.org/r/1410529254.3569.23.camel@tkhai
Cc: Alasdair Kergon 
Cc: Anil Belur 
Cc: Arnd Bergmann 
Cc: Dave Kleikamp 
Cc: David Airlie 
Cc: David Howells 
Cc: Dmitry Eremin 
Cc: Frank Blaschka 
Cc: Greg Kroah-Hartman 
Cc: Heiko Carstens 
Cc: Helge Deller 
Cc: Isaac Huang 
Cc: James E.J. Bottomley 
Cc: James E.J. Bottomley 
Cc: J. Bruce Fields 
Cc: Jeff Dike 
Cc: Jesper Nilsson 
Cc: Jiri Slaby 
Cc: Laura Abbott 
Cc: Liang Zhen 
Cc: Linus Torvalds 
Cc: Martin Schwidefsky 
Cc: Masaru Nomura 
Cc: Michael Opdenacker 
Cc: Mikael Starvik 
Cc: Mike Snitzer 
Cc: Neil Brown 
Cc: Oleg Drokin 
Cc: Peng Tao 
Cc: Richard Weinberger 
Cc: Robert Love 
Cc: Steven Rostedt 
Cc: Trond Myklebust 
Cc: Ursula Braun 
Cc: Zi Shen Lim 
Cc: devel@driverdev.osuosl.org
Cc: dm-devel@redhat.com
Cc: dri-devel@lists.freedesktop.org
Cc: fcoe-devel@open-fcoe.org
Cc: jfs-discussion@lists.sourceforge.net
Cc: linux390@de.ibm.com
Cc: linux-afs@lists.infradead.org
Cc: linux-cris-kernel@axis.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-nfs@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linux-raid@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: qla2xxx-upstream@qlogic.com
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: user-mode-linux-user@lists.sourceforge.net
Signed-off-by: Ingo Molnar

nohz: nohz full depends on irq work self IPI support

2014-09-13T16:46:41+00:00

The nohz full functionality depends on IRQ work to trigger its own
interrupts. As it's used to restart the tick, we can't rely on the tick
fallback for irq work callbacks, ie: we can't use the tick to restart
the tick itself.

Lets reject the full dynticks initialization if that arch support isn't
available.

As a side effect, this makes sure that nohz kick is never called from
the tick. That otherwise would result in illegal hrtimer self-cancellation
and lockup.

Acked-by: Peter Zijlstra (Intel) 
Cc: Ingo Molnar 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Signed-off-by: Frederic Weisbecker

nohz: Consolidate nohz full init code

2014-09-13T16:46:40+00:00

The supports for CONFIG_NO_HZ_FULL_ALL=y and the nohz_full= kernel
parameter both have their own way to do the same thing: allocate
full dynticks cpumasks, fill them and initialize some state variables.

Lets consolidate that all in the same place.

While at it, convert some regular printk message to warnings when
fundamental allocations fail.

Acked-by: Peter Zijlstra (Intel) 
Cc: Ingo Molnar 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Signed-off-by: Frederic Weisbecker

irq_work: Force raised irq work to run on irq work interrupt

2014-09-13T16:38:15+00:00

The nohz full kick, which restarts the tick when any resource depend
on it, can't be executed anywhere given the operation it does on timers.
If it is called from the scheduler or timers code, chances are that
we run into a deadlock.

This is why we run the nohz full kick from an irq work. That way we make
sure that the kick runs on a virgin context.

However if that's the case when irq work runs in its own dedicated
self-ipi, things are different for the big bunch of archs that don't
support the self triggered way. In order to support them, irq works are
also handled by the timer interrupt as fallback.

Now when irq works run on the timer interrupt, the context isn't blank.
More precisely, they can run in the context of the hrtimer that runs the
tick. But the nohz kick cancels and restarts this hrtimer and cancelling
an hrtimer from itself isn't allowed. This is why we run in an endless
loop:

	Kernel panic - not syncing: Watchdog detected hard LOCKUP on cpu 2
	CPU: 2 PID: 7538 Comm: kworker/u8:8 Not tainted 3.16.0+ #34
	Workqueue: btrfs-endio-write normal_work_helper [btrfs]
	 ffff880244c06c88 000000001b486fe1 ffff880244c06bf0 ffffffff8a7f1e37
	 ffffffff8ac52a18 ffff880244c06c78 ffffffff8a7ef928 0000000000000010
	 ffff880244c06c88 ffff880244c06c20 000000001b486fe1 0000000000000000
	Call Trace:
	 ] dump_stack+0x4e/0x7a
	 [] panic+0xd4/0x207
	 [] watchdog_overflow_callback+0x118/0x120
	 [] __perf_event_overflow+0xae/0x350
	 [] ? perf_event_task_disable+0xa0/0xa0
	 [] ? x86_perf_event_set_period+0xbf/0x150
	 [] perf_event_overflow+0x14/0x20
	 [] intel_pmu_handle_irq+0x206/0x410
	 [] perf_event_nmi_handler+0x2b/0x50
	 [] nmi_handle+0xd2/0x390
	 [] ? nmi_handle+0x5/0x390
	 [] ? match_held_lock+0x8/0x1b0
	 [] default_do_nmi+0x72/0x1c0
	 [] do_nmi+0xb8/0x100
	 [] end_repeat_nmi+0x1e/0x2e
	 [] ? match_held_lock+0x8/0x1b0
	 [] ? match_held_lock+0x8/0x1b0
	 [] ? match_held_lock+0x8/0x1b0
	 <] lock_acquired+0xaf/0x450
	 [] ? lock_hrtimer_base.isra.20+0x25/0x50
	 [] _raw_spin_lock_irqsave+0x78/0x90
	 [] ? lock_hrtimer_base.isra.20+0x25/0x50
	 [] lock_hrtimer_base.isra.20+0x25/0x50
	 [] hrtimer_try_to_cancel+0x33/0x1e0
	 [] hrtimer_cancel+0x1a/0x30
	 [] tick_nohz_restart+0x17/0x90
	 [] __tick_nohz_full_check+0xc3/0x100
	 [] nohz_full_kick_work_func+0xe/0x10
	 [] irq_work_run_list+0x44/0x70
	 [] irq_work_run+0x2a/0x50
	 [] update_process_times+0x5b/0x70
	 [] tick_sched_handle.isra.21+0x25/0x60
	 [] tick_sched_timer+0x41/0x60
	 [] __run_hrtimer+0x72/0x470
	 [] ? tick_sched_do_timer+0xb0/0xb0
	 [] hrtimer_interrupt+0x117/0x270
	 [] local_apic_timer_interrupt+0x37/0x60
	 [] smp_apic_timer_interrupt+0x3f/0x50
	 [] apic_timer_interrupt+0x6f/0x80

To fix this we force non-lazy irq works to run on irq work self-IPIs
when available. That ability of the arch to trigger irq work self IPIs
is available with arch_irq_work_has_interrupt().

Reported-by: Catalin Iacob 
Reported-by: Dave Jones 
Acked-by: Peter Zijlstra (Intel) 
Cc: Ingo Molnar 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Signed-off-by: Frederic Weisbecker