Dear RT Folks, I'm pleased to announce the 3.14.39-rt38 stable release. You can get this release via the git tree at: git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git branch: v3.14-rt Head SHA1: 7189db6fab1e3be351479097e6a043191e0f2c87 Or to build 3.14.39-rt38 directly, the following patches should be applied: http://www.kernel.org/pub/linux/kernel/v3.x/linux-3.14.tar.xz http://www.kernel.org/pub/linux/kernel/v3.x/patch-3.14.39.xz http://www.kernel.org/pub/linux/kernel/projects/rt/3.14/patch-3.14.39-rt38.patch.xz You can also build from 3.14.39-rt37 by applying the incremental patch: http://www.kernel.org/pub/linux/kernel/projects/rt/3.14/incr/patch-3.14.39-rt37-rt38.patch.xz Enjoy, -- Steve Changes from v3.14.39-rt37: --- Marcelo Tosatti (2): KVM: lapic: mark LAPIC timer handler as irqsafe KVM: use simple waitqueue for vcpu->wq Mike Galbraith (2): hotplug: Use set_cpus_allowed_ptr() in sync_unplug_thread() rt, nohz_full: fix nohz_full for PREEMPT_RT_FULL Sebastian Andrzej Siewior (1): kernel/irq_work: fix no_hz deadlock Steven Rostedt (Red Hat) (1): Linux 3.14.39-rt38 ---- arch/arm/kernel/smp.c | 2 -- arch/arm/kvm/arm.c | 4 ++-- arch/arm/kvm/psci.c | 4 ++-- arch/powerpc/include/asm/kvm_host.h | 4 ++-- arch/powerpc/kernel/time.c | 2 +- arch/powerpc/kvm/book3s_hv.c | 20 ++++++++-------- arch/s390/include/asm/kvm_host.h | 2 +- arch/sparc/kernel/pcr.c | 2 -- arch/x86/kernel/irq_work.c | 2 -- arch/x86/kvm/lapic.c | 48 ++++++++++++++++++++++++++++++++----- include/linux/kvm_host.h | 4 ++-- kernel/cpu.c | 2 +- kernel/irq_work.c | 5 +--- kernel/sched/core.c | 29 +++++++++++++++++----- kernel/time/tick-sched.c | 10 ++++++++ kernel/timer.c | 2 +- localversion-rt | 2 +- virt/kvm/async_pf.c | 4 ++-- virt/kvm/kvm_main.c | 16 ++++++------- 19 files changed, 109 insertions(+), 55 deletions(-) --------------------------- diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 686f1d1eb32e..8cd3724714fe 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -463,14 +463,12 @@ void arch_send_call_function_single_ipi(int cpu) } #ifdef CONFIG_IRQ_WORK -#ifndef CONFIG_PREEMPT_RT_FULL void arch_irq_work_raise(void) { if (is_smp()) smp_cross_call(cpumask_of(smp_processor_id()), IPI_IRQ_WORK); } #endif -#endif static const char *ipi_types[NR_IPI] = { #define S(x,s) [x] = s diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index bd18bb8b2770..9100f8a609a2 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -495,9 +495,9 @@ static int kvm_vcpu_first_run_init(struct kvm_vcpu *vcpu) static void vcpu_pause(struct kvm_vcpu *vcpu) { - wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu); + struct swait_head *wq = kvm_arch_vcpu_wq(vcpu); - wait_event_interruptible(*wq, !vcpu->arch.pause); + swait_event_interruptible(*wq, !vcpu->arch.pause); } static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu) diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index 448f60e8d23c..19c6c9c2118c 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -36,7 +36,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) { struct kvm *kvm = source_vcpu->kvm; struct kvm_vcpu *vcpu = NULL, *tmp; - wait_queue_head_t *wq; + struct swait_head *wq; unsigned long cpu_id; unsigned long mpidr; phys_addr_t target_pc; @@ -80,7 +80,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) smp_mb(); /* Make sure the above is visible */ wq = kvm_arch_vcpu_wq(vcpu); - wake_up_interruptible(wq); + swait_wake_interruptible(wq); return KVM_PSCI_RET_SUCCESS; } diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index 1eaea2dea174..dfaf2c2d8e7f 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -295,7 +295,7 @@ struct kvmppc_vcore { u8 in_guest; struct list_head runnable_threads; spinlock_t lock; - wait_queue_head_t wq; + struct swait_head wq; u64 stolen_tb; u64 preempt_tb; struct kvm_vcpu *runner; @@ -612,7 +612,7 @@ struct kvm_vcpu_arch { u8 prodded; u32 last_inst; - wait_queue_head_t *wqp; + struct swait_head *wqp; struct kvmppc_vcore *vcore; int ret; int trap; diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 6d37d7603a8f..5bec5fd82a7e 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -423,7 +423,7 @@ unsigned long profile_pc(struct pt_regs *regs) EXPORT_SYMBOL(profile_pc); #endif -#if defined(CONFIG_IRQ_WORK) && !defined(CONFIG_PREEMPT_RT_FULL) +#if defined(CONFIG_IRQ_WORK) /* * 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable... diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 7a25d9218a05..0019281510da 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -74,11 +74,11 @@ static void kvmppc_fast_vcpu_kick_hv(struct kvm_vcpu *vcpu) { int me; int cpu = vcpu->cpu; - wait_queue_head_t *wqp; + struct swait_head *wqp; wqp = kvm_arch_vcpu_wq(vcpu); - if (waitqueue_active(wqp)) { - wake_up_interruptible(wqp); + if (swaitqueue_active(wqp)) { + swait_wake_interruptible(wqp); ++vcpu->stat.halt_wakeup; } @@ -583,8 +583,8 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu) tvcpu->arch.prodded = 1; smp_mb(); if (vcpu->arch.ceded) { - if (waitqueue_active(&vcpu->wq)) { - wake_up_interruptible(&vcpu->wq); + if (swaitqueue_active(&vcpu->wq)) { + swait_wake_interruptible(&vcpu->wq); vcpu->stat.halt_wakeup++; } } @@ -1199,7 +1199,7 @@ static struct kvm_vcpu *kvmppc_core_vcpu_create_hv(struct kvm *kvm, if (vcore) { INIT_LIST_HEAD(&vcore->runnable_threads); spin_lock_init(&vcore->lock); - init_waitqueue_head(&vcore->wq); + init_swait_head(&vcore->wq); vcore->preempt_tb = TB_NIL; vcore->lpcr = kvm->arch.lpcr; vcore->first_vcpuid = core * threads_per_core; @@ -1566,13 +1566,13 @@ static void kvmppc_wait_for_exec(struct kvm_vcpu *vcpu, int wait_state) */ static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc) { - DEFINE_WAIT(wait); + DEFINE_SWAITER(wait); - prepare_to_wait(&vc->wq, &wait, TASK_INTERRUPTIBLE); + swait_prepare(&vc->wq, &wait, TASK_INTERRUPTIBLE); vc->vcore_state = VCORE_SLEEPING; spin_unlock(&vc->lock); schedule(); - finish_wait(&vc->wq, &wait); + swait_finish(&vc->wq, &wait); spin_lock(&vc->lock); vc->vcore_state = VCORE_INACTIVE; } @@ -1613,7 +1613,7 @@ static int kvmppc_run_vcpu(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu) kvmppc_create_dtl_entry(vcpu, vc); kvmppc_start_thread(vcpu); } else if (vc->vcore_state == VCORE_SLEEPING) { - wake_up(&vc->wq); + swait_wake(&vc->wq); } } diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index eef3dd3fd9a9..65402d300a26 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -233,7 +233,7 @@ struct kvm_s390_local_interrupt { atomic_t active; struct kvm_s390_float_interrupt *float_int; int timer_due; /* event indicator for waitqueue below */ - wait_queue_head_t *wq; + struct swait_head *wq; atomic_t *cpuflags; unsigned int action_bits; }; diff --git a/arch/sparc/kernel/pcr.c b/arch/sparc/kernel/pcr.c index 927d9c5e50f5..7e967c8018c8 100644 --- a/arch/sparc/kernel/pcr.c +++ b/arch/sparc/kernel/pcr.c @@ -43,12 +43,10 @@ void __irq_entry deferred_pcr_work_irq(int irq, struct pt_regs *regs) set_irq_regs(old_regs); } -#ifndef CONFIG_PREEMPT_RT_FULL void arch_irq_work_raise(void) { set_softint(1 << PIL_DEFERRED_PCR_WORK); } -#endif const struct pcr_ops *pcr_ops; EXPORT_SYMBOL_GPL(pcr_ops); diff --git a/arch/x86/kernel/irq_work.c b/arch/x86/kernel/irq_work.c index 3d21f7bd7b42..1de84e3ab4e0 100644 --- a/arch/x86/kernel/irq_work.c +++ b/arch/x86/kernel/irq_work.c @@ -38,7 +38,6 @@ __visible void smp_trace_irq_work_interrupt(struct pt_regs *regs) exiting_irq(); } -#ifndef CONFIG_PREEMPT_RT_FULL void arch_irq_work_raise(void) { #ifdef CONFIG_X86_LOCAL_APIC @@ -49,4 +48,3 @@ void arch_irq_work_raise(void) apic_wait_icr_idle(); #endif } -#endif diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 453e5fbbb7ae..8b25d010d5e4 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -1031,8 +1031,38 @@ static void update_divide_count(struct kvm_lapic *apic) apic->divide_count); } + +static enum hrtimer_restart apic_timer_fn(struct hrtimer *data); + +static void apic_timer_expired(struct hrtimer *data) +{ + int ret, i = 0; + enum hrtimer_restart r; + struct kvm_timer *ktimer = container_of(data, struct kvm_timer, timer); + + r = apic_timer_fn(data); + + if (r == HRTIMER_RESTART) { + do { + ret = hrtimer_start_expires(data, HRTIMER_MODE_ABS); + if (ret == -ETIME) + hrtimer_add_expires_ns(&ktimer->timer, + ktimer->period); + i++; + } while (ret == -ETIME && i < 10); + + if (ret == -ETIME) { + printk_once(KERN_ERR "%s: failed to reprogram timer\n", + __func__); + WARN_ON_ONCE(1); + } + } +} + + static void start_apic_timer(struct kvm_lapic *apic) { + int ret; ktime_t now; atomic_set(&apic->lapic_timer.pending, 0); @@ -1062,9 +1092,11 @@ static void start_apic_timer(struct kvm_lapic *apic) } } - hrtimer_start(&apic->lapic_timer.timer, + ret = hrtimer_start(&apic->lapic_timer.timer, ktime_add_ns(now, apic->lapic_timer.period), HRTIMER_MODE_ABS); + if (ret == -ETIME) + apic_timer_expired(&apic->lapic_timer.timer); apic_debug("%s: bus cycle is %" PRId64 "ns, now 0x%016" PRIx64 ", " @@ -1094,8 +1126,10 @@ static void start_apic_timer(struct kvm_lapic *apic) ns = (tscdeadline - guest_tsc) * 1000000ULL; do_div(ns, this_tsc_khz); } - hrtimer_start(&apic->lapic_timer.timer, + ret = hrtimer_start(&apic->lapic_timer.timer, ktime_add_ns(now, ns), HRTIMER_MODE_ABS); + if (ret == -ETIME) + apic_timer_expired(&apic->lapic_timer.timer); local_irq_restore(flags); } @@ -1533,7 +1567,7 @@ static enum hrtimer_restart apic_timer_fn(struct hrtimer *data) struct kvm_timer *ktimer = container_of(data, struct kvm_timer, timer); struct kvm_lapic *apic = container_of(ktimer, struct kvm_lapic, lapic_timer); struct kvm_vcpu *vcpu = apic->vcpu; - wait_queue_head_t *q = &vcpu->wq; + struct swait_head *q = &vcpu->wq; /* * There is a race window between reading and incrementing, but we do @@ -1547,8 +1581,8 @@ static enum hrtimer_restart apic_timer_fn(struct hrtimer *data) kvm_make_request(KVM_REQ_PENDING_TIMER, vcpu); } - if (waitqueue_active(q)) - wake_up_interruptible(q); + if (swaitqueue_active(q)) + swait_wake_interruptible(q); if (lapic_is_periodic(apic)) { hrtimer_add_expires_ns(&ktimer->timer, ktimer->period); @@ -1581,6 +1615,7 @@ int kvm_create_lapic(struct kvm_vcpu *vcpu) hrtimer_init(&apic->lapic_timer.timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); apic->lapic_timer.timer.function = apic_timer_fn; + apic->lapic_timer.timer.irqsafe = 1; /* * APIC is created enabled. This will prevent kvm_lapic_set_base from @@ -1699,7 +1734,8 @@ void __kvm_migrate_apic_timer(struct kvm_vcpu *vcpu) timer = &vcpu->arch.apic->lapic_timer.timer; if (hrtimer_cancel(timer)) - hrtimer_start_expires(timer, HRTIMER_MODE_ABS); + if (hrtimer_start_expires(timer, HRTIMER_MODE_ABS) == -ETIME) + apic_timer_expired(timer); } /* diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index b8e9a43e501a..aebf20c9bfab 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -231,7 +231,7 @@ struct kvm_vcpu { int fpu_active; int guest_fpu_loaded, guest_xcr0_loaded; - wait_queue_head_t wq; + struct swait_head wq; struct pid *pid; int sigset_active; sigset_t sigset; @@ -677,7 +677,7 @@ static inline bool kvm_arch_has_noncoherent_dma(struct kvm *kvm) } #endif -static inline wait_queue_head_t *kvm_arch_vcpu_wq(struct kvm_vcpu *vcpu) +static inline struct swait_head *kvm_arch_vcpu_wq(struct kvm_vcpu *vcpu) { #ifdef __KVM_HAVE_ARCH_WQP return vcpu->arch.wqp; diff --git a/kernel/cpu.c b/kernel/cpu.c index 285e18b2c420..a3890754e407 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -242,7 +242,7 @@ static int sync_unplug_thread(void *data) * we don't want any more work on this CPU. */ current->flags &= ~PF_NO_SETAFFINITY; - do_set_cpus_allowed(current, cpu_present_mask); + set_cpus_allowed_ptr(current, cpu_present_mask); migrate_me(); return 0; } diff --git a/kernel/irq_work.c b/kernel/irq_work.c index 35d21f93bbe8..5f7d93d89c7f 100644 --- a/kernel/irq_work.c +++ b/kernel/irq_work.c @@ -16,6 +16,7 @@ #include <linux/tick.h> #include <linux/cpu.h> #include <linux/notifier.h> +#include <linux/interrupt.h> #include <asm/processor.h> @@ -51,11 +52,7 @@ static bool irq_work_claim(struct irq_work *work) return true; } -#ifdef CONFIG_PREEMPT_RT_FULL -void arch_irq_work_raise(void) -#else void __weak arch_irq_work_raise(void) -#endif { /* * Lame architectures will get the timer tick callback diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 883669d3e293..71c0bb1cdeb0 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -696,17 +696,34 @@ static inline bool got_nohz_idle_kick(void) #endif /* CONFIG_NO_HZ_COMMON */ #ifdef CONFIG_NO_HZ_FULL + +static int ksoftirqd_running(void) +{ + struct task_struct *softirqd; + + if (!IS_ENABLED(CONFIG_PREEMPT_RT_FULL)) + return 0; + softirqd = this_cpu_ksoftirqd(); + if (softirqd && softirqd->on_rq) + return 1; + return 0; +} + bool sched_can_stop_tick(void) { - struct rq *rq; + struct rq *rq; - rq = this_rq(); + rq = this_rq(); - /* Make sure rq->nr_running update is visible after the IPI */ - smp_rmb(); + /* Make sure rq->nr_running update is visible after the IPI */ + smp_rmb(); - /* More than one running task need preemption */ - if (rq->nr_running > 1) + /* + * More than one running task need preemption + * + * NOTE, RT: if ksoftirqd is awake, subtract it. + */ + if (rq->nr_running - ksoftirqd_running() > 1) return false; return true; diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index ab32130964b6..57d5bb1b3919 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -180,6 +180,11 @@ static bool can_stop_full_tick(void) return false; } + if (!arch_irq_work_has_interrupt()) { + trace_tick_stop(0, "missing irq work interrupt\n"); + return false; + } + /* sched_clock_tick() needs us? */ #ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK /* @@ -221,7 +226,12 @@ void __tick_nohz_full_check(void) static void nohz_full_kick_work_func(struct irq_work *work) { + unsigned long flags; + + /* ksoftirqd processes sirqs with interrupts enabled */ + local_irq_save(flags); __tick_nohz_full_check(); + local_irq_restore(flags); } static DEFINE_PER_CPU(struct irq_work, nohz_full_kick_work) = { diff --git a/kernel/timer.c b/kernel/timer.c index 34fd2dbba3e3..36b9f10bb3c7 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -1450,7 +1450,7 @@ void update_process_times(int user_tick) scheduler_tick(); run_local_timers(); rcu_check_callbacks(cpu, user_tick); -#if defined(CONFIG_IRQ_WORK) +#if defined(CONFIG_IRQ_WORK) && !defined(CONFIG_PREEMPT_RT_FULL) if (in_irq()) irq_work_run(); #endif diff --git a/localversion-rt b/localversion-rt index a3b2408c1da6..49bae8d6aa67 100644 --- a/localversion-rt +++ b/localversion-rt @@ -1 +1 @@ --rt37 +-rt38 diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c index f2c80d5451c3..10634baf3b08 100644 --- a/virt/kvm/async_pf.c +++ b/virt/kvm/async_pf.c @@ -82,8 +82,8 @@ static void async_pf_execute(struct work_struct *work) trace_kvm_async_pf_completed(addr, gva); - if (waitqueue_active(&vcpu->wq)) - wake_up_interruptible(&vcpu->wq); + if (swaitqueue_active(&vcpu->wq)) + swait_wake_interruptible(&vcpu->wq); mmput(mm); kvm_put_kvm(vcpu->kvm); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 66112533b1e9..38a0d7a5ce74 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -219,7 +219,7 @@ int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id) vcpu->kvm = kvm; vcpu->vcpu_id = id; vcpu->pid = NULL; - init_waitqueue_head(&vcpu->wq); + init_swait_head(&vcpu->wq); kvm_async_pf_vcpu_init(vcpu); page = alloc_page(GFP_KERNEL | __GFP_ZERO); @@ -1675,10 +1675,10 @@ EXPORT_SYMBOL_GPL(mark_page_dirty); */ void kvm_vcpu_block(struct kvm_vcpu *vcpu) { - DEFINE_WAIT(wait); + DEFINE_SWAITER(wait); for (;;) { - prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE); + swait_prepare(&vcpu->wq, &wait, TASK_INTERRUPTIBLE); if (kvm_arch_vcpu_runnable(vcpu)) { kvm_make_request(KVM_REQ_UNHALT, vcpu); @@ -1692,7 +1692,7 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu) schedule(); } - finish_wait(&vcpu->wq, &wait); + swait_finish(&vcpu->wq, &wait); } EXPORT_SYMBOL_GPL(kvm_vcpu_block); @@ -1704,11 +1704,11 @@ void kvm_vcpu_kick(struct kvm_vcpu *vcpu) { int me; int cpu = vcpu->cpu; - wait_queue_head_t *wqp; + struct swait_head *wqp; wqp = kvm_arch_vcpu_wq(vcpu); - if (waitqueue_active(wqp)) { - wake_up_interruptible(wqp); + if (swaitqueue_active(wqp)) { + swait_wake_interruptible(wqp); ++vcpu->stat.halt_wakeup; } @@ -1814,7 +1814,7 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me) continue; if (vcpu == me) continue; - if (waitqueue_active(&vcpu->wq)) + if (swaitqueue_active(&vcpu->wq)) continue; if (!kvm_vcpu_eligible_for_directed_yield(vcpu)) continue; -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
