[ANNOUNCE] 3.18.27-rt26

From: Steven Rostedt
Date: Mon Feb 29 2016 - 12:05:26 EST



Dear RT Folks,

I'm pleased to announce the 3.18.27-rt26 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: v3.18-rt
Head SHA1: 9df6942317afb556a87b905a0c1137c06d6b53a3


Or to build 3.18.27-rt26 directly, the following patches should be applied:

http://www.kernel.org/pub/linux/kernel/v3.x/linux-3.18.tar.xz

http://www.kernel.org/pub/linux/kernel/v3.x/patch-3.18.27.xz

http://www.kernel.org/pub/linux/kernel/projects/rt/3.18/patch-3.18.27-rt26.patch.xz



You can also build from 3.18.27-rt25 by applying the incremental patch:

http://www.kernel.org/pub/linux/kernel/projects/rt/3.18/incr/patch-3.18.27-rt25-rt26.patch.xz



Enjoy,

-- Steve


Changes from v3.18.27-rt25:

---

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 3.18.27-rt26

Thomas Gleixner (3):
genirq: Handle force threading of interrupts with primary and thread handler
rtmutex: Handle non enqueued waiters gracefully
irqwork: Move irq safe work to irq context

Wolfgang M. Reimer (1):
locking: locktorture: Do NOT include rwlock.h directly

bmouring@xxxxxx (1):
rtmutex: Use chainwalking control enum

----
arch/arm/kernel/smp.c | 5 +-
arch/x86/kernel/dumpstack_32.c | 4 +-
arch/x86/kernel/dumpstack_64.c | 8 +-
drivers/cpufreq/cpufreq.c | 34 +-------
include/linux/interrupt.h | 2 +
include/linux/irq_work.h | 6 ++
include/trace/events/sched.h | 30 +++++---
kernel/irq/manage.c | 158 ++++++++++++++++++++++++++++----------
kernel/irq_work.c | 9 +++
kernel/locking/locktorture.c | 1 -
kernel/locking/rtmutex.c | 4 +-
kernel/sched/core.c | 8 +-
kernel/time/timer.c | 6 +-
kernel/trace/trace_sched_switch.c | 2 +-
kernel/trace/trace_sched_wakeup.c | 2 +-
lib/dump_stack.c | 6 +-
localversion-rt | 2 +-
net/core/dev.c | 4 +-
18 files changed, 183 insertions(+), 108 deletions(-)
---------------------------
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index a8e32aaf0383..6e9b81666a23 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -208,8 +208,6 @@ int __cpu_disable(void)
flush_cache_louis();
local_flush_tlb_all();

- clear_tasks_mm_cpumask(cpu);
-
return 0;
}

@@ -225,6 +223,9 @@ 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_32.c b/arch/x86/kernel/dumpstack_32.c
index 5abd4cd4230c..1282817bb4c3 100644
--- a/arch/x86/kernel/dumpstack_32.c
+++ b/arch/x86/kernel/dumpstack_32.c
@@ -42,7 +42,7 @@ 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();
int graph = 0;
u32 *prev_esp;

@@ -86,7 +86,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
break;
touch_nmi_watchdog();
}
- put_cpu();
+ put_cpu_light();
}
EXPORT_SYMBOL(dump_trace);

diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index ff86f19b5758..4821f291890f 100644
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -152,7 +152,7 @@ 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();
struct thread_info *tinfo;
unsigned long *irq_stack = (unsigned long *)per_cpu(irq_stack_ptr, cpu);
unsigned long dummy;
@@ -241,7 +241,7 @@ 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);

@@ -255,7 +255,7 @@ 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));
@@ -288,7 +288,7 @@ 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 90e8deb6c15e..7a9c1a7ecfe5 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -53,12 +53,6 @@ static inline bool has_target(void)
return cpufreq_driver->target_index || cpufreq_driver->target;
}

-/*
- * 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);
@@ -205,9 +199,6 @@ 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);

@@ -220,9 +211,6 @@ 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);
@@ -233,7 +221,6 @@ void cpufreq_cpu_put(struct cpufreq_policy *policy)
return;

kobject_put(&policy->kobj);
- up_read(&cpufreq_rwsem);
}
EXPORT_SYMBOL_GPL(cpufreq_cpu_put);

@@ -762,9 +749,6 @@ static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
struct freq_attr *fattr = to_attr(attr);
ssize_t ret;

- if (!down_read_trylock(&cpufreq_rwsem))
- return -EINVAL;
-
down_read(&policy->rwsem);

if (fattr->show)
@@ -773,7 +757,6 @@ static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
ret = -EIO;

up_read(&policy->rwsem);
- up_read(&cpufreq_rwsem);

return ret;
}
@@ -790,9 +773,6 @@ 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;
-
down_write(&policy->rwsem);

if (fattr->store)
@@ -801,8 +781,6 @@ static ssize_t store(struct kobject *kobj, struct attribute *attr,
ret = -EIO;

up_write(&policy->rwsem);
-
- up_read(&cpufreq_rwsem);
unlock:
put_online_cpus();

@@ -1142,9 +1120,6 @@ 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);
@@ -1152,7 +1127,6 @@ 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);
- up_read(&cpufreq_rwsem);
return ret;
}
}
@@ -1288,7 +1262,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
up_write(&policy->rwsem);

kobject_uevent(&policy->kobj, KOBJ_ADD);
- up_read(&cpufreq_rwsem);

pr_debug("initialization complete\n");

@@ -1314,8 +1287,6 @@ err_set_policy_cpu:
cpufreq_policy_free(policy);

nomem_out:
- up_read(&cpufreq_rwsem);
-
return ret;
}

@@ -2528,19 +2499,20 @@ 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);
if (cpufreq_boost_supported())
cpufreq_sysfs_remove_file(&boost.attr);

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/interrupt.h b/include/linux/interrupt.h
index 33cfbc085a94..86628c733be7 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -100,6 +100,7 @@ typedef irqreturn_t (*irq_handler_t)(int, void *);
* @flags: flags (see IRQF_* above)
* @thread_fn: interrupt handler function for threaded interrupts
* @thread: thread pointer for threaded interrupts
+ * @secondary: pointer to secondary irqaction (force threading)
* @thread_flags: flags related to @thread
* @thread_mask: bitmask for keeping track of @thread activity
* @dir: pointer to the proc/irq/NN/name entry
@@ -111,6 +112,7 @@ struct irqaction {
struct irqaction *next;
irq_handler_t thread_fn;
struct task_struct *thread;
+ struct irqaction *secondary;
unsigned int irq;
unsigned int flags;
unsigned long thread_flags;
diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h
index 30ef6c214e6f..af7ed9ad52c3 100644
--- a/include/linux/irq_work.h
+++ b/include/linux/irq_work.h
@@ -51,4 +51,10 @@ 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 a7d67bc14906..09f27eb85ef8 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/manage.c b/kernel/irq/manage.c
index 382cbe57abf3..70f59992c201 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -735,6 +735,12 @@ static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
return IRQ_NONE;
}

+static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
+{
+ WARN(1, "Secondary action handler called for irq %d\n", irq);
+ return IRQ_NONE;
+}
+
static int irq_wait_for_interrupt(struct irqaction *action)
{
set_current_state(TASK_INTERRUPTIBLE);
@@ -761,7 +767,8 @@ static int irq_wait_for_interrupt(struct irqaction *action)
static void irq_finalize_oneshot(struct irq_desc *desc,
struct irqaction *action)
{
- if (!(desc->istate & IRQS_ONESHOT))
+ if (!(desc->istate & IRQS_ONESHOT) ||
+ action->handler == irq_forced_secondary_handler)
return;
again:
chip_bus_lock(desc);
@@ -923,6 +930,18 @@ static void irq_thread_dtor(struct callback_head *unused)
irq_finalize_oneshot(desc, action);
}

+static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
+{
+ struct irqaction *secondary = action->secondary;
+
+ if (WARN_ON_ONCE(!secondary))
+ return;
+
+ raw_spin_lock_irq(&desc->lock);
+ __irq_wake_thread(desc, secondary);
+ raw_spin_unlock_irq(&desc->lock);
+}
+
/*
* Interrupt handler thread
*/
@@ -953,6 +972,8 @@ static int irq_thread(void *data)
action_ret = handler_fn(desc, action);
if (action_ret == IRQ_HANDLED)
atomic_inc(&desc->threads_handled);
+ if (action_ret == IRQ_WAKE_THREAD)
+ irq_wake_secondary(desc, action);

#ifdef CONFIG_PREEMPT_RT_FULL
migrate_disable();
@@ -1003,20 +1024,36 @@ void irq_wake_thread(unsigned int irq, void *dev_id)
}
EXPORT_SYMBOL_GPL(irq_wake_thread);

-static void irq_setup_forced_threading(struct irqaction *new)
+static int irq_setup_forced_threading(struct irqaction *new)
{
if (!force_irqthreads)
- return;
+ return 0;
if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
- return;
+ return 0;

new->flags |= IRQF_ONESHOT;

- if (!new->thread_fn) {
- set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
- new->thread_fn = new->handler;
- new->handler = irq_default_primary_handler;
+ /*
+ * Handle the case where we have a real primary handler and a
+ * thread handler. We force thread them as well by creating a
+ * secondary action.
+ */
+ if (new->handler != irq_default_primary_handler && new->thread_fn) {
+ /* Allocate the secondary action */
+ new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
+ if (!new->secondary)
+ return -ENOMEM;
+ new->secondary->handler = irq_forced_secondary_handler;
+ new->secondary->thread_fn = new->thread_fn;
+ new->secondary->dev_id = new->dev_id;
+ new->secondary->irq = new->irq;
+ new->secondary->name = new->name;
}
+ /* Deal with the primary handler */
+ set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
+ new->thread_fn = new->handler;
+ new->handler = irq_default_primary_handler;
+ return 0;
}

static int irq_request_resources(struct irq_desc *desc)
@@ -1036,6 +1073,48 @@ static void irq_release_resources(struct irq_desc *desc)
c->irq_release_resources(d);
}

+static int
+setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
+{
+ struct task_struct *t;
+ struct sched_param param = {
+ .sched_priority = MAX_USER_RT_PRIO/2,
+ };
+
+ if (!secondary) {
+ t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
+ new->name);
+ } else {
+ t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
+ new->name);
+ param.sched_priority += 1;
+ }
+
+ if (IS_ERR(t))
+ return PTR_ERR(t);
+
+ sched_setscheduler_nocheck(t, SCHED_FIFO, &param);
+
+ /*
+ * We keep the reference to the task struct even if
+ * the thread dies to avoid that the interrupt code
+ * references an already freed task_struct.
+ */
+ get_task_struct(t);
+ new->thread = t;
+ /*
+ * Tell the thread to set its affinity. This is
+ * important for shared interrupt handlers as we do
+ * not invoke setup_affinity() for the secondary
+ * handlers as everything is already set up. Even for
+ * interrupts marked with IRQF_NO_BALANCE this is
+ * correct as we want the thread to move to the cpu(s)
+ * on which the requesting code placed the interrupt.
+ */
+ set_bit(IRQTF_AFFINITY, &new->thread_flags);
+ return 0;
+}
+
/*
* Internal function to register an irqaction - typically used to
* allocate special interrupts that are part of the architecture.
@@ -1056,6 +1135,8 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
if (!try_module_get(desc->owner))
return -ENODEV;

+ new->irq = irq;
+
/*
* Check whether the interrupt nests into another interrupt
* thread.
@@ -1073,8 +1154,11 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
*/
new->handler = irq_nested_primary_handler;
} else {
- if (irq_settings_can_thread(desc))
- irq_setup_forced_threading(new);
+ if (irq_settings_can_thread(desc)) {
+ ret = irq_setup_forced_threading(new);
+ if (ret)
+ goto out_mput;
+ }
}

/*
@@ -1083,37 +1167,14 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
* thread.
*/
if (new->thread_fn && !nested) {
- struct task_struct *t;
- static const struct sched_param param = {
- .sched_priority = MAX_USER_RT_PRIO/2,
- };
-
- t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
- new->name);
- if (IS_ERR(t)) {
- ret = PTR_ERR(t);
+ ret = setup_irq_thread(new, irq, false);
+ if (ret)
goto out_mput;
+ if (new->secondary) {
+ ret = setup_irq_thread(new->secondary, irq, true);
+ if (ret)
+ goto out_thread;
}
-
- sched_setscheduler_nocheck(t, SCHED_FIFO, &param);
-
- /*
- * We keep the reference to the task struct even if
- * the thread dies to avoid that the interrupt code
- * references an already freed task_struct.
- */
- get_task_struct(t);
- new->thread = t;
- /*
- * Tell the thread to set its affinity. This is
- * important for shared interrupt handlers as we do
- * not invoke setup_affinity() for the secondary
- * handlers as everything is already set up. Even for
- * interrupts marked with IRQF_NO_BALANCE this is
- * correct as we want the thread to move to the cpu(s)
- * on which the requesting code placed the interrupt.
- */
- set_bit(IRQTF_AFFINITY, &new->thread_flags);
}

if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
@@ -1289,7 +1350,6 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
irq, nmsk, omsk);
}

- new->irq = irq;
*old_ptr = new;

irq_pm_install_action(desc, new);
@@ -1315,6 +1375,8 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
*/
if (new->thread)
wake_up_process(new->thread);
+ if (new->secondary)
+ wake_up_process(new->secondary->thread);

register_irq_proc(irq, desc);
new->dir = NULL;
@@ -1345,6 +1407,13 @@ out_thread:
kthread_stop(t);
put_task_struct(t);
}
+ if (new->secondary && new->secondary->thread) {
+ struct task_struct *t = new->secondary->thread;
+
+ new->secondary->thread = NULL;
+ kthread_stop(t);
+ put_task_struct(t);
+ }
out_mput:
module_put(desc->owner);
return ret;
@@ -1452,9 +1521,14 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
if (action->thread) {
kthread_stop(action->thread);
put_task_struct(action->thread);
+ if (action->secondary && action->secondary->thread) {
+ kthread_stop(action->secondary->thread);
+ put_task_struct(action->secondary->thread);
+ }
}

module_put(desc->owner);
+ kfree(action->secondary);
return action;
}

@@ -1593,8 +1667,10 @@ int request_threaded_irq(unsigned int irq, irq_handler_t handler,
retval = __setup_irq(irq, desc, action);
chip_bus_sync_unlock(desc);

- if (retval)
+ if (retval) {
+ kfree(action->secondary);
kfree(action);
+ }

#ifdef CONFIG_DEBUG_SHIRQ_FIXME
if (!retval && (irqflags & IRQF_SHARED)) {
diff --git a/kernel/irq_work.c b/kernel/irq_work.c
index 9678fd1382a7..3d5a476b58b9 100644
--- a/kernel/irq_work.c
+++ b/kernel/irq_work.c
@@ -200,8 +200,17 @@ 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/locking/locktorture.c b/kernel/locking/locktorture.c
index ec8cce259779..aa60d919e336 100644
--- a/kernel/locking/locktorture.c
+++ b/kernel/locking/locktorture.c
@@ -24,7 +24,6 @@
#include <linux/module.h>
#include <linux/kthread.h>
#include <linux/spinlock.h>
-#include <linux/rwlock.h>
#include <linux/mutex.h>
#include <linux/rwsem.h>
#include <linux/smp.h>
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 64973df0c686..8d950b4521fc 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -1008,7 +1008,7 @@ 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 (;;) {
@@ -2144,7 +2144,7 @@ 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 7e844b4f1701..9e01a8f358f8 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1606,9 +1606,9 @@ 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);
@@ -1832,6 +1832,8 @@ 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);

@@ -2247,7 +2249,7 @@ void wake_up_new_task(struct task_struct *p)
rq = __task_rq_lock(p);
activate_task(rq, p, 0);
p->on_rq = TASK_ON_RQ_QUEUED;
- 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/time/timer.c b/kernel/time/timer.c
index 3a978d000fce..78e39b644780 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -1451,7 +1451,7 @@ void update_process_times(int user_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_tick();
#endif
@@ -1467,9 +1467,7 @@ 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 3f34dc9b40f3..9586cde520b0 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 19bd8928ce94..808258ccf6c5 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -460,7 +460,7 @@ 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 c30d07e99dba..01ca6dae9414 100644
--- a/lib/dump_stack.c
+++ b/lib/dump_stack.c
@@ -25,7 +25,6 @@ static atomic_t dump_lock = ATOMIC_INIT(-1);

asmlinkage __visible void dump_stack(void)
{
- unsigned long flags;
int was_locked;
int old;
int cpu;
@@ -34,8 +33,8 @@ asmlinkage __visible void dump_stack(void)
* Permit this cpu to perform nested stack dumps while serialising
* against other CPUs
*/
+ migrate_disable();
retry:
- local_irq_save(flags);
cpu = smp_processor_id();
old = atomic_cmpxchg(&dump_lock, -1, cpu);
if (old == -1) {
@@ -43,7 +42,6 @@ retry:
} else if (old == cpu) {
was_locked = 1;
} else {
- local_irq_restore(flags);
cpu_relax();
goto retry;
}
@@ -53,7 +51,7 @@ retry:
if (!was_locked)
atomic_set(&dump_lock, -1);

- local_irq_restore(flags);
+ migrate_enable();
}
#else
asmlinkage __visible void dump_stack(void)
diff --git a/localversion-rt b/localversion-rt
index c5b71f9a229d..2e9afd4a0afd 100644
--- a/localversion-rt
+++ b/localversion-rt
@@ -1 +1 @@
--rt25
+-rt26
diff --git a/net/core/dev.c b/net/core/dev.c
index 1cbcf08cc224..39d2a0ba38ed 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6813,7 +6813,7 @@ 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();
@@ -7065,7 +7065,7 @@ static int dev_cpu_callback(struct notifier_block *nfb,
netif_rx_internal(skb);
input_queue_head_incr(oldsd);
}
- while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) {
+ while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) {
netif_rx_internal(skb);
input_queue_head_incr(oldsd);
}