linux/kernel/irq_work.c, branch v4.15

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

2017-11-14T01:33:11Z

Pull irq core updates from Thomas Gleixner: "A rather large update for the interrupt core code and the irq chip drivers: - Add a new bitmap matrix allocator and supporting changes, which is used to replace the x86 vector allocator which comes with separate pull request. This allows to replace the convoluted nested loop allocation function in x86 with a facility which supports the recently added property of managed interrupts proper and allows to switch to a best effort vector reservation scheme, which addresses problems with vector exhaustion. - A large update to the ARM GIC-V3-ITS driver adding support for range selectors. - New interrupt controllers: - Meson and Meson8 GPIO - BCM7271 L2 - Socionext EXIU If you expected that this will stop at some point, I have to disappoint you. There are new ones posted already. Sigh! - STM32 interrupt controller support for new platforms. - A pile of fixes, cleanups and updates to the MIPS GIC driver - The usual small fixes, cleanups and updates all over the place. Most visible one is to move the irq chip drivers Kconfig switches into a separate Kconfig menu" * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits) genirq: Fix type of shifting literal 1 in __setup_irq() irqdomain: Drop pointless NULL check in virq_debug_show_one genirq/proc: Return proper error code when irq_set_affinity() fails irq/work: Use llist_for_each_entry_safe irqchip: mips-gic: Print warning if inherited GIC base is used irqchip/mips-gic: Add pr_fmt and reword pr_* messages irqchip/stm32: Move the wakeup on interrupt mask irqchip/stm32: Fix initial values irqchip/stm32: Add stm32h7 support dt-bindings/interrupt-controllers: Add compatible string for stm32h7 irqchip/stm32: Add multi-bank management irqchip/stm32: Select GENERIC_IRQ_CHIP irqchip/exiu: Add support for Socionext Synquacer EXIU controller dt-bindings: Add description of Socionext EXIU interrupt controller irqchip/gic-v3-its: Fix VPE activate callback return value irqchip: mips-gic: Make IPI bitmaps static irqchip: mips-gic: Share register writes in gic_set_type() irqchip: mips-gic: Remove gic_vpes variable irqchip: mips-gic: Use num_possible_cpus() to reserve IPIs irqchip: mips-gic: Configure EIC when CPUs come online ...

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

2017-11-13T20:38:26Z

Pull core locking updates from Ingo Molnar: "The main changes in this cycle are: - Another attempt at enabling cross-release lockdep dependency tracking (automatically part of CONFIG_PROVE_LOCKING=y), this time with better performance and fewer false positives. (Byungchul Park) - Introduce lockdep_assert_irqs_enabled()/disabled() and convert open-coded equivalents to lockdep variants. (Frederic Weisbecker) - Add down_read_killable() and use it in the VFS's iterate_dir() method. (Kirill Tkhai) - Convert remaining uses of ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE(). Most of the conversion was Coccinelle driven. (Mark Rutland, Paul E. McKenney) - Get rid of lockless_dereference(), by strengthening Alpha atomics, strengthening READ_ONCE() with smp_read_barrier_depends() and thus being able to convert users of lockless_dereference() to READ_ONCE(). (Will Deacon) - Various micro-optimizations: - better PV qspinlocks (Waiman Long), - better x86 barriers (Michael S. Tsirkin) - better x86 refcounts (Kees Cook) - ... plus other fixes and enhancements. (Borislav Petkov, Juergen Gross, Miguel Bernal Marin)" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits) locking/x86: Use LOCK ADD for smp_mb() instead of MFENCE rcu: Use lockdep to assert IRQs are disabled/enabled netpoll: Use lockdep to assert IRQs are disabled/enabled timers/posix-cpu-timers: Use lockdep to assert IRQs are disabled/enabled sched/clock, sched/cputime: Use lockdep to assert IRQs are disabled/enabled irq_work: Use lockdep to assert IRQs are disabled/enabled irq/timings: Use lockdep to assert IRQs are disabled/enabled perf/core: Use lockdep to assert IRQs are disabled/enabled x86: Use lockdep to assert IRQs are disabled/enabled smp/core: Use lockdep to assert IRQs are disabled/enabled timers/hrtimer: Use lockdep to assert IRQs are disabled/enabled timers/nohz: Use lockdep to assert IRQs are disabled/enabled workqueue: Use lockdep to assert IRQs are disabled/enabled irq/softirqs: Use lockdep to assert IRQs are disabled/enabled locking/lockdep: Add IRQs disabled/enabled assertion APIs: lockdep_assert_irqs_enabled()/disabled() locking/pvqspinlock: Implement hybrid PV queued/unfair locks locking/rwlocks: Fix comments x86/paravirt: Set up the virt_spin_lock_key after static keys get initialized block, locking/lockdep: Assign a lock_class per gendisk used for wait_for_completion() workqueue: Remove now redundant lock acquisitions wrt. workqueue flushes ...

irq/work: Use llist_for_each_entry_safe

2017-11-12T12:15:14Z

The llist_for_each_entry() loop in irq_work_run_list() is unsafe because once the works PENDING bit is cleared it can be requeued on another CPU. Use llist_for_each_entry_safe() instead. Fixes: 16c0890dc66d ("irq/work: Don't reinvent the wheel but use existing llist API") Reported-by:Chris Wilson Signed-off-by: Thomas Gleixner Cc: Frederic Weisbecker Cc: Byungchul Park Cc: Peter Zijlstra Cc: Petri Latvala Link: http://lkml.kernel.org/r/151027307351.14762.4611888896020658384@mail.alporthouse.com

irq_work: Use lockdep to assert IRQs are disabled/enabled

2017-11-08T10:13:52Z

Use lockdep to check that IRQs are enabled or disabled as expected. This way the sanity check only shows overhead when concurrency correctness debug code is enabled. Signed-off-by: Frederic Weisbecker Acked-by: Thomas Gleixner Cc: David S . Miller Cc: Lai Jiangshan Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Tejun Heo Link: http://lkml.kernel.org/r/1509980490-4285-11-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar

irq/work: Don't reinvent the wheel but use existing llist API

2017-10-31T09:24:39Z

Use the proper llist APIs instead of open-coded variants of them. Signed-off-by: Byungchul Park Signed-off-by: Frederic Weisbecker Acked-by: Thomas Gleixner Cc: Linus Torvalds Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1509414414-14987-1-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar

irq_work: Map irq_work_on_queue() to irq_work_on() in !SMP

2017-10-09T21:24:14Z

Commit 478850160636 ("irq_work: Implement remote queueing") provides irq_work_on_queue() only for SMP builds. However, providing it simplifies code that submits irq_work to lists of CPUs, eliminating the !SMP special cases. This commit therefore maps irq_work_on_queue() to irq_work_on() in !SMP builds, but validating the specified CPU. Signed-off-by: Paul E. McKenney

treewide: Remove old email address

2015-11-23T08:44:58Z

There were still a number of references to my old Red Hat email address in the kernel source. Remove these while keeping the Red Hat copyright notices intact. Signed-off-by: Peter Zijlstra (Intel) Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver Signed-off-by: Ingo Molnar

percpu: Convert remaining __get_cpu_var uses in 3.18-rcX

2014-10-29T15:18:18Z

During the 3.18 merge period additional __get_cpu_var uses were added. The patch converts these to this_cpu_ptr(). Signed-off-by: Christoph Lameter Acked-by: Will Deacon Acked-by: Thomas Gleixner Signed-off-by: Tejun Heo

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

2014-10-15T05:48:18Z

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 ...

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

2014-09-13T16:38:15Z

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