Dear RT Folks, I'm pleased to announce the 3.12.54-rt73 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: v3.12-rt Head SHA1: ca4a3e96670bf4ad6a49a9020513f7bb99ded08b Or to build 3.12.54-rt73 directly, the following patches should be applied: http://www.kernel.org/pub/linux/kernel/v3.x/linux-3.12.tar.xz http://www.kernel.org/pub/linux/kernel/v3.x/patch-3.12.54.xz http://www.kernel.org/pub/linux/kernel/projects/rt/3.12/patch-3.12.54-rt73.patch.xz You can also build from 3.12.54-rt72 by applying the incremental patch: http://www.kernel.org/pub/linux/kernel/projects/rt/3.12/incr/patch-3.12.54-rt72-rt73.patch.xz Enjoy, -- Steve Changes from v3.12.54-rt72: --- Grygorii Strashko (2): ARM: smp: Move clear_tasks_mm_cpumask() call to __cpu_die() net/core/cpuhotplug: Drain input_pkt_queue lockless Josh Cartwright (1): net: Make synchronize_rcu_expedited() conditional on !RT_FULL Peter Zijlstra (1): sched: Introduce the trace_sched_waking tracepoint Sebastian Andrzej Siewior (2): cpufreq: Remove cpufreq_rwsem dump stack: don't disable preemption during trace Steven Rostedt (Red Hat) (1): Linux 3.12.54-rt73 Thomas Gleixner (2): rtmutex: Handle non enqueued waiters gracefully irqwork: Move irq safe work to irq context bmouring@xxxxxx (1): rtmutex: Use chainwalking control enum ---- arch/arm/kernel/smp.c | 5 ++-- arch/x86/kernel/dumpstack_64.c | 8 +++---- drivers/cpufreq/cpufreq.c | 49 ++++++--------------------------------- include/linux/irq_work.h | 6 +++++ include/trace/events/sched.h | 30 +++++++++++++++++------- kernel/irq_work.c | 9 +++++++ kernel/rtmutex.c | 4 ++-- kernel/sched/core.c | 8 ++++--- kernel/timer.c | 6 ++--- kernel/trace/trace_sched_switch.c | 2 +- kernel/trace/trace_sched_wakeup.c | 2 +- lib/dump_stack.c | 4 ++-- localversion-rt | 2 +- net/core/dev.c | 4 ++-- 14 files changed, 66 insertions(+), 73 deletions(-) --------------------------- diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index bd1b9e633356..2f7325963bf5 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -207,8 +207,6 @@ int __cpu_disable(void) flush_cache_louis(); local_flush_tlb_all(); - clear_tasks_mm_cpumask(cpu); - return 0; } @@ -224,6 +222,9 @@ void __cpu_die(unsigned int cpu) pr_err("CPU%u: cpu didn't die\n", cpu); return; } + + clear_tasks_mm_cpumask(cpu); + printk(KERN_NOTICE "CPU%u: shutdown\n", cpu); /* diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c index 66e274a3d968..37aee503a7ba 100644 --- a/arch/x86/kernel/dumpstack_64.c +++ b/arch/x86/kernel/dumpstack_64.c @@ -114,7 +114,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs, unsigned long *stack, unsigned long bp, const struct stacktrace_ops *ops, void *data) { - const unsigned cpu = get_cpu(); + const unsigned cpu = get_cpu_light(); unsigned long *irq_stack_end = (unsigned long *)per_cpu(irq_stack_ptr, cpu); unsigned used = 0; @@ -191,7 +191,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs, * This handles the process stack: */ bp = ops->walk_stack(tinfo, stack, bp, ops, data, NULL, &graph); - put_cpu(); + put_cpu_light(); } EXPORT_SYMBOL(dump_trace); @@ -205,7 +205,7 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs, int cpu; int i; - preempt_disable(); + migrate_disable(); cpu = smp_processor_id(); irq_stack_end = (unsigned long *)(per_cpu(irq_stack_ptr, cpu)); @@ -238,7 +238,7 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs, pr_cont(" %016lx", *stack++); touch_nmi_watchdog(); } - preempt_enable(); + migrate_enable(); pr_cont("\n"); show_trace_log_lvl(task, regs, sp, bp, log_lvl); diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 8356b481e339..012d5169eee2 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -90,12 +90,6 @@ static void unlock_policy_rwsem_##mode(int cpu) \ unlock_policy_rwsem(read, cpu); unlock_policy_rwsem(write, cpu); -/* - * rwsem to guarantee that cpufreq driver module doesn't unload during critical - * sections - */ -static DECLARE_RWSEM(cpufreq_rwsem); - /* internal prototypes */ static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event); @@ -191,9 +185,6 @@ struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) if (cpufreq_disabled() || (cpu >= nr_cpu_ids)) return NULL; - if (!down_read_trylock(&cpufreq_rwsem)) - return NULL; - /* get the cpufreq driver */ read_lock_irqsave(&cpufreq_driver_lock, flags); @@ -206,9 +197,6 @@ struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) read_unlock_irqrestore(&cpufreq_driver_lock, flags); - if (!policy) - up_read(&cpufreq_rwsem); - return policy; } EXPORT_SYMBOL_GPL(cpufreq_cpu_get); @@ -219,7 +207,6 @@ void cpufreq_cpu_put(struct cpufreq_policy *policy) return; kobject_put(&policy->kobj); - up_read(&cpufreq_rwsem); } EXPORT_SYMBOL_GPL(cpufreq_cpu_put); @@ -664,13 +651,10 @@ static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) { struct cpufreq_policy *policy = to_policy(kobj); struct freq_attr *fattr = to_attr(attr); - ssize_t ret = -EINVAL; - - if (!down_read_trylock(&cpufreq_rwsem)) - goto exit; + ssize_t ret; if (lock_policy_rwsem_read(policy->cpu) < 0) - goto up_read; + return -EINVAL; if (fattr->show) ret = fattr->show(policy, buf); @@ -679,9 +663,6 @@ static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) unlock_policy_rwsem_read(policy->cpu); -up_read: - up_read(&cpufreq_rwsem); -exit: return ret; } @@ -697,11 +678,8 @@ static ssize_t store(struct kobject *kobj, struct attribute *attr, if (!cpu_online(policy->cpu)) goto unlock; - if (!down_read_trylock(&cpufreq_rwsem)) - goto unlock; - if (lock_policy_rwsem_write(policy->cpu) < 0) - goto up_read; + goto unlock; if (fattr->store) ret = fattr->store(policy, buf, count); @@ -710,8 +688,6 @@ static ssize_t store(struct kobject *kobj, struct attribute *attr, unlock_policy_rwsem_write(policy->cpu); -up_read: - up_read(&cpufreq_rwsem); unlock: put_online_cpus(); @@ -1011,9 +987,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, } #endif - if (!down_read_trylock(&cpufreq_rwsem)) - return 0; - #ifdef CONFIG_HOTPLUG_CPU /* Check if this cpu was hot-unplugged earlier and has siblings */ read_lock_irqsave(&cpufreq_driver_lock, flags); @@ -1021,7 +994,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, if (cpumask_test_cpu(cpu, tpolicy->related_cpus)) { read_unlock_irqrestore(&cpufreq_driver_lock, flags); ret = cpufreq_add_policy_cpu(tpolicy, cpu, dev, frozen); - up_read(&cpufreq_rwsem); return ret; } } @@ -1035,7 +1007,7 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, policy = cpufreq_policy_alloc(); if (!policy) - goto nomem_out; + return ret; /* @@ -1106,7 +1078,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, cpufreq_init_policy(policy); kobject_uevent(&policy->kobj, KOBJ_ADD); - up_read(&cpufreq_rwsem); pr_debug("initialization complete\n"); @@ -1120,8 +1091,6 @@ err_out_unregister: err_set_policy_cpu: cpufreq_policy_free(policy); -nomem_out: - up_read(&cpufreq_rwsem); return ret; } @@ -1474,9 +1443,6 @@ unsigned int cpufreq_get(unsigned int cpu) if (cpufreq_disabled() || !cpufreq_driver) return -ENOENT; - if (!down_read_trylock(&cpufreq_rwsem)) - return 0; - if (unlikely(lock_policy_rwsem_read(cpu))) goto out_policy; @@ -1485,8 +1451,6 @@ unsigned int cpufreq_get(unsigned int cpu) unlock_policy_rwsem_read(cpu); out_policy: - up_read(&cpufreq_rwsem); - return ret_freq; } EXPORT_SYMBOL(cpufreq_get); @@ -2184,16 +2148,17 @@ int cpufreq_unregister_driver(struct cpufreq_driver *driver) pr_debug("unregistering driver %s\n", driver->name); + /* Protect against concurrent cpu hotplug */ + get_online_cpus(); subsys_interface_unregister(&cpufreq_interface); unregister_hotcpu_notifier(&cpufreq_cpu_notifier); - down_write(&cpufreq_rwsem); write_lock_irqsave(&cpufreq_driver_lock, flags); cpufreq_driver = NULL; write_unlock_irqrestore(&cpufreq_driver_lock, flags); - up_write(&cpufreq_rwsem); + put_online_cpus(); return 0; } diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h index 4a8c7a2df480..ccd736ebee9e 100644 --- a/include/linux/irq_work.h +++ b/include/linux/irq_work.h @@ -44,4 +44,10 @@ bool irq_work_needs_cpu(void); static inline bool irq_work_needs_cpu(void) { return false; } #endif +#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL) +void irq_work_tick_soft(void); +#else +static inline void irq_work_tick_soft(void) { } +#endif + #endif /* _LINUX_IRQ_WORK_H */ diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h index 2e7d9947a10d..004eb037865c 100644 --- a/include/trace/events/sched.h +++ b/include/trace/events/sched.h @@ -55,9 +55,9 @@ TRACE_EVENT(sched_kthread_stop_ret, */ DECLARE_EVENT_CLASS(sched_wakeup_template, - TP_PROTO(struct task_struct *p, int success), + TP_PROTO(struct task_struct *p), - TP_ARGS(__perf_task(p), success), + TP_ARGS(__perf_task(p)), TP_STRUCT__entry( __array( char, comm, TASK_COMM_LEN ) @@ -71,25 +71,37 @@ DECLARE_EVENT_CLASS(sched_wakeup_template, memcpy(__entry->comm, p->comm, TASK_COMM_LEN); __entry->pid = p->pid; __entry->prio = p->prio; - __entry->success = success; + __entry->success = 1; /* rudiment, kill when possible */ __entry->target_cpu = task_cpu(p); ), - TP_printk("comm=%s pid=%d prio=%d success=%d target_cpu=%03d", + TP_printk("comm=%s pid=%d prio=%d target_cpu=%03d", __entry->comm, __entry->pid, __entry->prio, - __entry->success, __entry->target_cpu) + __entry->target_cpu) ); +/* + * Tracepoint called when waking a task; this tracepoint is guaranteed to be + * called from the waking context. + */ +DEFINE_EVENT(sched_wakeup_template, sched_waking, + TP_PROTO(struct task_struct *p), + TP_ARGS(p)); + +/* + * Tracepoint called when the task is actually woken; p->state == TASK_RUNNNG. + * It it not always called from the waking context. + */ DEFINE_EVENT(sched_wakeup_template, sched_wakeup, - TP_PROTO(struct task_struct *p, int success), - TP_ARGS(p, success)); + TP_PROTO(struct task_struct *p), + TP_ARGS(p)); /* * Tracepoint for waking up a new task: */ DEFINE_EVENT(sched_wakeup_template, sched_wakeup_new, - TP_PROTO(struct task_struct *p, int success), - TP_ARGS(p, success)); + TP_PROTO(struct task_struct *p), + TP_ARGS(p)); #ifdef CREATE_TRACE_POINTS static inline long __trace_sched_switch_state(struct task_struct *p) diff --git a/kernel/irq_work.c b/kernel/irq_work.c index af8ceafc94e4..883bb73698b9 100644 --- a/kernel/irq_work.c +++ b/kernel/irq_work.c @@ -163,8 +163,17 @@ void irq_work_tick(void) if (!llist_empty(raised) && !arch_irq_work_has_interrupt()) irq_work_run_list(raised); + + if (!IS_ENABLED(CONFIG_PREEMPT_RT_FULL)) + irq_work_run_list(this_cpu_ptr(&lazy_list)); +} + +#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL) +void irq_work_tick_soft(void) +{ irq_work_run_list(this_cpu_ptr(&lazy_list)); } +#endif /* * Synchronize against the irq_work @entry, ensures the entry is not diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c index 7601c1332a88..8061201b3163 100644 --- a/kernel/rtmutex.c +++ b/kernel/rtmutex.c @@ -1182,7 +1182,7 @@ static void noinline __sched rt_spin_lock_slowlock(struct rt_mutex *lock) __set_current_state(TASK_UNINTERRUPTIBLE); pi_unlock(&self->pi_lock); - ret = task_blocks_on_rt_mutex(lock, &waiter, self, 0); + ret = task_blocks_on_rt_mutex(lock, &waiter, self, RT_MUTEX_MIN_CHAINWALK); BUG_ON(ret); for (;;) { @@ -2065,7 +2065,7 @@ int rt_mutex_start_proxy_lock(struct rt_mutex *lock, ret = 0; } - if (unlikely(ret)) + if (ret && rt_mutex_has_waiters(lock)) remove_waiter(lock, waiter); raw_spin_unlock(&lock->wait_lock); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 3e8b790e5c17..14b5ba66fa72 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1394,9 +1394,9 @@ static void ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags) { check_preempt_curr(rq, p, wake_flags); - trace_sched_wakeup(p, true); - p->state = TASK_RUNNING; + trace_sched_wakeup(p); + #ifdef CONFIG_SMP if (p->sched_class->task_woken) p->sched_class->task_woken(rq, p); @@ -1581,6 +1581,8 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) if (!(wake_flags & WF_LOCK_SLEEPER)) p->saved_state = TASK_RUNNING; + trace_sched_waking(p); + success = 1; /* we're going to change ->state */ cpu = task_cpu(p); @@ -1826,7 +1828,7 @@ void wake_up_new_task(struct task_struct *p) rq = __task_rq_lock(p); activate_task(rq, p, 0); p->on_rq = 1; - trace_sched_wakeup_new(p, true); + trace_sched_wakeup_new(p); check_preempt_curr(rq, p, WF_FORK); #ifdef CONFIG_SMP if (p->sched_class->task_woken) diff --git a/kernel/timer.c b/kernel/timer.c index bf1277c2203b..400ef0bde253 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) && !defined(CONFIG_PREEMPT_RT_FULL) +#if defined(CONFIG_IRQ_WORK) if (in_irq()) irq_work_run(); #endif @@ -1466,9 +1466,7 @@ static void run_timer_softirq(struct softirq_action *h) hrtimer_run_pending(); -#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL) - irq_work_tick(); -#endif + irq_work_tick_soft(); if (time_after_eq(jiffies, base->timer_jiffies)) __run_timers(base); diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index 4e98e3b257a3..82fe794af532 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -106,7 +106,7 @@ tracing_sched_wakeup_trace(struct trace_array *tr, } static void -probe_sched_wakeup(void *ignore, struct task_struct *wakee, int success) +probe_sched_wakeup(void *ignore, struct task_struct *wakee) { struct trace_array_cpu *data; unsigned long flags; diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index fee77e15d815..8e967ca56006 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -458,7 +458,7 @@ static void wakeup_reset(struct trace_array *tr) } static void -probe_wakeup(void *ignore, struct task_struct *p, int success) +probe_wakeup(void *ignore, struct task_struct *p) { struct trace_array_cpu *data; int cpu = smp_processor_id(); diff --git a/lib/dump_stack.c b/lib/dump_stack.c index f23b63f0a1c3..b39c60b1f12c 100644 --- a/lib/dump_stack.c +++ b/lib/dump_stack.c @@ -33,7 +33,7 @@ asmlinkage void dump_stack(void) * Permit this cpu to perform nested stack dumps while serialising * against other CPUs */ - preempt_disable(); + migrate_disable(); retry: cpu = smp_processor_id(); @@ -52,7 +52,7 @@ retry: if (!was_locked) atomic_set(&dump_lock, -1); - preempt_enable(); + migrate_enable(); } #else asmlinkage void dump_stack(void) diff --git a/localversion-rt b/localversion-rt index 2c95a3cdbcb8..e8ada8cdb471 100644 --- a/localversion-rt +++ b/localversion-rt @@ -1 +1 @@ --rt72 +-rt73 diff --git a/net/core/dev.c b/net/core/dev.c index 30fd8898bcfb..cfec8a542d35 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6231,7 +6231,7 @@ EXPORT_SYMBOL(free_netdev); void synchronize_net(void) { might_sleep(); - if (rtnl_is_locked()) + if (rtnl_is_locked() && !IS_ENABLED(CONFIG_PREEMPT_RT_FULL)) synchronize_rcu_expedited(); else synchronize_rcu(); @@ -6481,7 +6481,7 @@ static int dev_cpu_callback(struct notifier_block *nfb, netif_rx(skb); input_queue_head_incr(oldsd); } - while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) { + while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) { netif_rx(skb); input_queue_head_incr(oldsd); } -- 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
