[ANNOUNCE] 3.12.0-rt2

[Sebastian Andrzej Siewior]

Dear RT folks!

I'm pleased to announce the v3.12.0-rt2 patch set.

Changes since v3.12.0-rt1
- fix for iwlwifi which tried to take a sleeping in irq context. Patch
has been available & disabled in the queue and is now enabled after Clark
recently reported that it works.
- tried to fix AT91's "already-free IRQ" and highres problem. Michael
Langfinge reported it initially and Sami Pietikäinen sent a patch for
the "already-free IRQ" problem. Based on another patch I looked at the
highres patch and tried to fix it. As I don't have the hardware, some
feedback would be nice.
- a fix for cpu down on !RT. Patch by Tiejun Chen.
- Mike Galbraith and Matt Cowell reported a dead lock with CONFIG_NO_HZ_FULL.
To fix this trylock deadlock, the sleeping lock is now taken with irqs off.
I would be interrested if this change causes any noticable latencys
for anyone.

Known issues:

- bcache is disabled.

- an ancient race (since we got sleeping spinlocks) where the
TASK_TRACED state is temporary replaced while waiting on a rw
lock and the task can't be traced.

The delta patch against v3.12.0-rt1 is appended below and can be found
here:
https://www.kernel.org/pub/linux/kernel/projects/rt/3.12/incr/patch-3.12.0-rt1-rt2.patch.xz

The RT patch against 3.12 can be found here:

https://www.kernel.org/pub/linux/kernel/projects/rt/3.12/patch-3.12.0-rt2.patch.xz

The split quilt queue is available at:

https://www.kernel.org/pub/linux/kernel/projects/rt/3.12/patches-3.12.0-rt2.tar.xz

Sebastian

diff --git a/arch/arm/mach-at91/at91rm9200_time.c b/arch/arm/mach-at91/at91rm9200_time.c
index 0bbd8e6..35f7b26 100644
--- a/arch/arm/mach-at91/at91rm9200_time.c
+++ b/arch/arm/mach-at91/at91rm9200_time.c
@@ -134,7 +134,7 @@ clkevt32k_mode(enum clock_event_mode mode, struct clock_event_device *dev)
break;
case CLOCK_EVT_MODE_SHUTDOWN:
case CLOCK_EVT_MODE_UNUSED:
- remove_irq(AT91_ID_SYS, &at91rm9200_timer_irq);
+ remove_irq(NR_IRQS_LEGACY + AT91_ID_SYS, &at91rm9200_timer_irq);
case CLOCK_EVT_MODE_RESUME:
irqmask = 0;
break;
diff --git a/arch/arm/mach-at91/at91sam926x_time.c b/arch/arm/mach-at91/at91sam926x_time.c
index 01681e6..1c4c487 100644
--- a/arch/arm/mach-at91/at91sam926x_time.c
+++ b/arch/arm/mach-at91/at91sam926x_time.c
@@ -87,7 +87,7 @@ pit_clkevt_mode(enum clock_event_mode mode, struct clock_event_device *dev)
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
/* Set up irq handler */
- setup_irq(AT91_ID_SYS, &at91sam926x_pit_irq);
+ setup_irq(at91sam926x_pit_irq.irq, &at91sam926x_pit_irq);
/* update clocksource counter */
pit_cnt += pit_cycle * PIT_PICNT(pit_read(AT91_PIT_PIVR));
pit_write(AT91_PIT_MR, (pit_cycle - 1) | AT91_PIT_PITEN
@@ -100,7 +100,7 @@ pit_clkevt_mode(enum clock_event_mode mode, struct clock_event_device *dev)
case CLOCK_EVT_MODE_UNUSED:
/* disable irq, leaving the clocksource active */
pit_write(AT91_PIT_MR, (pit_cycle - 1) | AT91_PIT_PITEN);
- remove_irq(AT91_ID_SYS, &at91sam926x_pit_irq);
+ remove_irq(at91sam926x_pit_irq.irq, &at91sam926x_pit_irq);
break;
case CLOCK_EVT_MODE_RESUME:
break;
diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
index c08ec1d..74fe7f7 100644
--- a/drivers/clocksource/tcb_clksrc.c
+++ b/drivers/clocksource/tcb_clksrc.c
@@ -182,9 +182,10 @@ static struct irqaction tc_irqaction = {
.handler = ch2_irq,
};

-static void __init setup_clkevents(struct atmel_tc *tc, int divisor_idx)
+static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
{
- unsigned divisor = atmel_tc_divisors[divisor_idx];
+ unsigned divisor = atmel_tc_divisors[clk32k_divisor_idx];
+ u32 freq;
struct clk *t2_clk = tc->clk[2];
int irq = tc->irq[2];

@@ -193,10 +194,14 @@ static void __init setup_clkevents(struct atmel_tc *tc, int divisor_idx)
tc_irqaction.dev_id = &clkevt;

timer_clock = clk32k_divisor_idx;
+ if (!divisor)
+ freq = 32768;
+ else
+ freq = clk_get_rate(t2_clk) / divisor;

clkevt.clkevt.cpumask = cpumask_of(0);

- clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff);
+ clockevents_config_and_register(&clkevt.clkevt, freq, 1, 0xffff);

setup_irq(irq, &tc_irqaction);
}
diff --git a/drivers/net/wireless/iwlwifi/pcie/trans.c b/drivers/net/wireless/iwlwifi/pcie/trans.c
index c3f904d..d07cdca 100644
--- a/drivers/net/wireless/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/iwlwifi/pcie/trans.c
@@ -1375,6 +1375,20 @@ static const struct iwl_trans_ops trans_ops_pcie = {
.set_bits_mask = iwl_trans_pcie_set_bits_mask,
};

+#ifdef CONFIG_PREEMPT_RT_BASE
+static irqreturn_t iwl_rt_irq_handler(int irq, void *dev_id)
+{
+ irqreturn_t ret;
+
+ local_bh_disable();
+ ret = iwl_pcie_isr_ict(irq, dev_id);
+ local_bh_enable();
+ if (ret == IRQ_WAKE_THREAD)
+ ret = iwl_pcie_irq_handler(irq, dev_id);
+ return ret;
+}
+#endif
+
struct iwl_trans *iwl_trans_pcie_alloc(struct pci_dev *pdev,
const struct pci_device_id *ent,
const struct iwl_cfg *cfg)
@@ -1493,9 +1507,14 @@ struct iwl_trans *iwl_trans_pcie_alloc(struct pci_dev *pdev,
if (iwl_pcie_alloc_ict(trans))
goto out_free_cmd_pool;

+#ifdef CONFIG_PREEMPT_RT_BASE
+ err = request_threaded_irq(pdev->irq, NULL, iwl_rt_irq_handler,
+ IRQF_SHARED | IRQF_ONESHOT, DRV_NAME, trans);
+#else
err = request_threaded_irq(pdev->irq, iwl_pcie_isr_ict,
iwl_pcie_irq_handler,
IRQF_SHARED, DRV_NAME, trans);
+#endif
if (err) {
IWL_ERR(trans, "Error allocating IRQ %d\n", pdev->irq);
goto out_free_ict;
diff --git a/kernel/cpu.c b/kernel/cpu.c
index f07af96..c36b075 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -593,6 +593,7 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
err = -EBUSY;
goto restore_cpus;
}
+ migrate_enable();

cpu_hotplug_begin();
err = cpu_unplug_begin(cpu);
@@ -646,7 +647,6 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
out_release:
cpu_unplug_done(cpu);
out_cancel:
- migrate_enable();
cpu_hotplug_done();
if (!err)
cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu);
diff --git a/kernel/futex.c b/kernel/futex.c
index 0ef419d..404d0bd 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -891,7 +891,7 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this)
if (pi_state->owner != current)
return -EINVAL;

- raw_spin_lock(&pi_state->pi_mutex.wait_lock);
+ raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock);
new_owner = rt_mutex_next_owner(&pi_state->pi_mutex);

/*
@@ -917,21 +917,21 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this)
else if (curval != uval)
ret = -EINVAL;
if (ret) {
- raw_spin_unlock(&pi_state->pi_mutex.wait_lock);
+ raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock);
return ret;
}
}

- raw_spin_lock_irq(&pi_state->owner->pi_lock);
+ raw_spin_lock(&pi_state->owner->pi_lock);
WARN_ON(list_empty(&pi_state->list));
list_del_init(&pi_state->list);
- raw_spin_unlock_irq(&pi_state->owner->pi_lock);
+ raw_spin_unlock(&pi_state->owner->pi_lock);

- raw_spin_lock_irq(&new_owner->pi_lock);
+ raw_spin_lock(&new_owner->pi_lock);
WARN_ON(!list_empty(&pi_state->list));
list_add(&pi_state->list, &new_owner->pi_state_list);
pi_state->owner = new_owner;
- raw_spin_unlock_irq(&new_owner->pi_lock);
+ raw_spin_unlock(&new_owner->pi_lock);

raw_spin_unlock(&pi_state->pi_mutex.wait_lock);
rt_mutex_unlock(&pi_state->pi_mutex);
@@ -1762,11 +1762,11 @@ static int fixup_owner(u32 __user *uaddr, struct futex_q *q, int locked)
* we returned due to timeout or signal without taking the
* rt_mutex. Too late.
*/
- raw_spin_lock(&q->pi_state->pi_mutex.wait_lock);
+ raw_spin_lock_irq(&q->pi_state->pi_mutex.wait_lock);
owner = rt_mutex_owner(&q->pi_state->pi_mutex);
if (!owner)
owner = rt_mutex_next_owner(&q->pi_state->pi_mutex);
- raw_spin_unlock(&q->pi_state->pi_mutex.wait_lock);
+ raw_spin_unlock_irq(&q->pi_state->pi_mutex.wait_lock);
ret = fixup_pi_state_owner(uaddr, q, owner);
goto out;
}
diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c
index b4c651e..c2f3f63 100644
--- a/kernel/rtmutex.c
+++ b/kernel/rtmutex.c
@@ -298,7 +298,7 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
plist_add(&waiter->list_entry, &lock->wait_list);

/* Release the task */
- raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+ raw_spin_unlock(&task->pi_lock);
if (!rt_mutex_owner(lock)) {
struct rt_mutex_waiter *lock_top_waiter;

@@ -309,7 +309,7 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
lock_top_waiter = rt_mutex_top_waiter(lock);
if (top_waiter != lock_top_waiter)
rt_mutex_wake_waiter(lock_top_waiter);
- raw_spin_unlock(&lock->wait_lock);
+ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
goto out_put_task;
}
put_task_struct(task);
@@ -317,7 +317,7 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
/* Grab the next task */
task = rt_mutex_owner(lock);
get_task_struct(task);
- raw_spin_lock_irqsave(&task->pi_lock, flags);
+ raw_spin_lock(&task->pi_lock);

if (waiter == rt_mutex_top_waiter(lock)) {
/* Boost the owner */
@@ -335,10 +335,10 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
__rt_mutex_adjust_prio(task);
}

- raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+ raw_spin_unlock(&task->pi_lock);

top_waiter = rt_mutex_top_waiter(lock);
- raw_spin_unlock(&lock->wait_lock);
+ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);

if (!detect_deadlock && waiter != top_waiter)
goto out_put_task;
@@ -425,10 +425,9 @@ __try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
/* We got the lock. */

if (waiter || rt_mutex_has_waiters(lock)) {
- unsigned long flags;
struct rt_mutex_waiter *top;

- raw_spin_lock_irqsave(&task->pi_lock, flags);
+ raw_spin_lock(&task->pi_lock);

/* remove the queued waiter. */
if (waiter) {
@@ -445,7 +444,7 @@ __try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
top->pi_list_entry.prio = top->list_entry.prio;
plist_add(&top->pi_list_entry, &task->pi_waiters);
}
- raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+ raw_spin_unlock(&task->pi_lock);
}

debug_rt_mutex_lock(lock);
@@ -478,10 +477,9 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
{
struct task_struct *owner = rt_mutex_owner(lock);
struct rt_mutex_waiter *top_waiter = waiter;
- unsigned long flags;
int chain_walk = 0, res;

- raw_spin_lock_irqsave(&task->pi_lock, flags);
+ raw_spin_lock(&task->pi_lock);

/*
* In the case of futex requeue PI, this will be a proxy
@@ -493,7 +491,7 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
* the task if PI_WAKEUP_INPROGRESS is set.
*/
if (task != current && task->pi_blocked_on == PI_WAKEUP_INPROGRESS) {
- raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+ raw_spin_unlock(&task->pi_lock);
return -EAGAIN;
}

@@ -512,20 +510,20 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,

task->pi_blocked_on = waiter;

- raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+ raw_spin_unlock(&task->pi_lock);

if (!owner)
return 0;

if (waiter == rt_mutex_top_waiter(lock)) {
- raw_spin_lock_irqsave(&owner->pi_lock, flags);
+ raw_spin_lock(&owner->pi_lock);
plist_del(&top_waiter->pi_list_entry, &owner->pi_waiters);
plist_add(&waiter->pi_list_entry, &owner->pi_waiters);

__rt_mutex_adjust_prio(owner);
if (rt_mutex_real_waiter(owner->pi_blocked_on))
chain_walk = 1;
- raw_spin_unlock_irqrestore(&owner->pi_lock, flags);
+ raw_spin_unlock(&owner->pi_lock);
}
else if (debug_rt_mutex_detect_deadlock(waiter, detect_deadlock))
chain_walk = 1;
@@ -540,12 +538,12 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
*/
get_task_struct(owner);

- raw_spin_unlock(&lock->wait_lock);
+ raw_spin_unlock_irq(&lock->wait_lock);

res = rt_mutex_adjust_prio_chain(owner, detect_deadlock, lock, waiter,
task);

- raw_spin_lock(&lock->wait_lock);
+ raw_spin_lock_irq(&lock->wait_lock);

return res;
}
@@ -560,9 +558,8 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
static void wakeup_next_waiter(struct rt_mutex *lock)
{
struct rt_mutex_waiter *waiter;
- unsigned long flags;

- raw_spin_lock_irqsave(&current->pi_lock, flags);
+ raw_spin_lock(&current->pi_lock);

waiter = rt_mutex_top_waiter(lock);

@@ -576,7 +573,7 @@ static void wakeup_next_waiter(struct rt_mutex *lock)

rt_mutex_set_owner(lock, NULL);

- raw_spin_unlock_irqrestore(&current->pi_lock, flags);
+ raw_spin_unlock(&current->pi_lock);

rt_mutex_wake_waiter(waiter);
}
@@ -592,20 +589,19 @@ static void remove_waiter(struct rt_mutex *lock,
{
int first = (waiter == rt_mutex_top_waiter(lock));
struct task_struct *owner = rt_mutex_owner(lock);
- unsigned long flags;
int chain_walk = 0;

- raw_spin_lock_irqsave(&current->pi_lock, flags);
+ raw_spin_lock(&current->pi_lock);
plist_del(&waiter->list_entry, &lock->wait_list);
current->pi_blocked_on = NULL;
- raw_spin_unlock_irqrestore(&current->pi_lock, flags);
+ raw_spin_unlock(&current->pi_lock);

if (!owner)
return;

if (first) {

- raw_spin_lock_irqsave(&owner->pi_lock, flags);
+ raw_spin_lock(&owner->pi_lock);

plist_del(&waiter->pi_list_entry, &owner->pi_waiters);

@@ -620,7 +616,7 @@ static void remove_waiter(struct rt_mutex *lock,
if (rt_mutex_real_waiter(owner->pi_blocked_on))
chain_walk = 1;

- raw_spin_unlock_irqrestore(&owner->pi_lock, flags);
+ raw_spin_unlock(&owner->pi_lock);
}

WARN_ON(!plist_node_empty(&waiter->pi_list_entry));
@@ -631,11 +627,11 @@ static void remove_waiter(struct rt_mutex *lock,
/* gets dropped in rt_mutex_adjust_prio_chain()! */
get_task_struct(owner);

- raw_spin_unlock(&lock->wait_lock);
+ raw_spin_unlock_irq(&lock->wait_lock);

rt_mutex_adjust_prio_chain(owner, 0, lock, NULL, current);

- raw_spin_lock(&lock->wait_lock);
+ raw_spin_lock_irq(&lock->wait_lock);
}

/*
@@ -723,9 +719,6 @@ static int adaptive_wait(struct rt_mutex *lock,
}
#endif

-# define pi_lock(lock) raw_spin_lock_irq(lock)
-# define pi_unlock(lock) raw_spin_unlock_irq(lock)
-
/*
* Slow path lock function spin_lock style: this variant is very
* careful not to miss any non-lock wakeups.
@@ -737,19 +730,22 @@ static void noinline __sched rt_spin_lock_slowlock(struct rt_mutex *lock)
{
struct task_struct *lock_owner, *self = current;
struct rt_mutex_waiter waiter, *top_waiter;
+ unsigned long flags;
int ret;

rt_mutex_init_waiter(&waiter, true);

- raw_spin_lock(&lock->wait_lock);
+ raw_local_save_flags(flags);
+ raw_spin_lock_irq(&lock->wait_lock);
init_lists(lock);

if (__try_to_take_rt_mutex(lock, self, NULL, STEAL_LATERAL)) {
- raw_spin_unlock(&lock->wait_lock);
+ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
return;
}

BUG_ON(rt_mutex_owner(lock) == self);
+ BUG_ON(arch_irqs_disabled_flags(flags));

/*
* We save whatever state the task is in and we'll restore it
@@ -757,10 +753,10 @@ static void noinline __sched rt_spin_lock_slowlock(struct rt_mutex *lock)
* as well. We are serialized via pi_lock against wakeups. See
* try_to_wake_up().
*/
- pi_lock(&self->pi_lock);
+ raw_spin_lock(&self->pi_lock);
self->saved_state = self->state;
__set_current_state(TASK_UNINTERRUPTIBLE);
- pi_unlock(&self->pi_lock);
+ raw_spin_unlock(&self->pi_lock);

ret = task_blocks_on_rt_mutex(lock, &waiter, self, 0);
BUG_ON(ret);
@@ -773,18 +769,18 @@ static void noinline __sched rt_spin_lock_slowlock(struct rt_mutex *lock)
top_waiter = rt_mutex_top_waiter(lock);
lock_owner = rt_mutex_owner(lock);

- raw_spin_unlock(&lock->wait_lock);
+ raw_spin_unlock_irq(&lock->wait_lock);

debug_rt_mutex_print_deadlock(&waiter);

if (top_waiter != &waiter || adaptive_wait(lock, lock_owner))
schedule_rt_mutex(lock);

- raw_spin_lock(&lock->wait_lock);
+ raw_spin_lock_irq(&lock->wait_lock);

- pi_lock(&self->pi_lock);
+ raw_spin_lock(&self->pi_lock);
__set_current_state(TASK_UNINTERRUPTIBLE);
- pi_unlock(&self->pi_lock);
+ raw_spin_unlock(&self->pi_lock);
}

/*
@@ -794,10 +790,10 @@ static void noinline __sched rt_spin_lock_slowlock(struct rt_mutex *lock)
* happened while we were blocked. Clear saved_state so
* try_to_wakeup() does not get confused.
*/
- pi_lock(&self->pi_lock);
+ raw_spin_lock(&self->pi_lock);
__set_current_state(self->saved_state);
self->saved_state = TASK_RUNNING;
- pi_unlock(&self->pi_lock);
+ raw_spin_unlock(&self->pi_lock);

/*
* try_to_take_rt_mutex() sets the waiter bit
@@ -808,7 +804,7 @@ static void noinline __sched rt_spin_lock_slowlock(struct rt_mutex *lock)
BUG_ON(rt_mutex_has_waiters(lock) && &waiter == rt_mutex_top_waiter(lock));
BUG_ON(!plist_node_empty(&waiter.list_entry));

- raw_spin_unlock(&lock->wait_lock);
+ raw_spin_unlock_irq(&lock->wait_lock);

debug_rt_mutex_free_waiter(&waiter);
}
@@ -818,7 +814,9 @@ static void noinline __sched rt_spin_lock_slowlock(struct rt_mutex *lock)
*/
static void noinline __sched rt_spin_lock_slowunlock(struct rt_mutex *lock)
{
- raw_spin_lock(&lock->wait_lock);
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&lock->wait_lock, flags);

debug_rt_mutex_unlock(lock);

@@ -826,13 +824,13 @@ static void noinline __sched rt_spin_lock_slowunlock(struct rt_mutex *lock)

if (!rt_mutex_has_waiters(lock)) {
lock->owner = NULL;
- raw_spin_unlock(&lock->wait_lock);
+ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
return;
}

wakeup_next_waiter(lock);

- raw_spin_unlock(&lock->wait_lock);
+ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);

/* Undo pi boosting.when necessary */
rt_mutex_adjust_prio(current);
@@ -1032,13 +1030,13 @@ __rt_mutex_slowlock(struct rt_mutex *lock, int state,
break;
}

- raw_spin_unlock(&lock->wait_lock);
+ raw_spin_unlock_irq(&lock->wait_lock);

debug_rt_mutex_print_deadlock(waiter);

schedule_rt_mutex(lock);

- raw_spin_lock(&lock->wait_lock);
+ raw_spin_lock_irq(&lock->wait_lock);
set_current_state(state);
}

@@ -1130,20 +1128,23 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
int detect_deadlock, struct ww_acquire_ctx *ww_ctx)
{
struct rt_mutex_waiter waiter;
+ unsigned long flags;
int ret = 0;

rt_mutex_init_waiter(&waiter, false);

- raw_spin_lock(&lock->wait_lock);
+ raw_local_save_flags(flags);
+ raw_spin_lock_irq(&lock->wait_lock);
init_lists(lock);

/* Try to acquire the lock again: */
if (try_to_take_rt_mutex(lock, current, NULL)) {
if (ww_ctx)
ww_mutex_account_lock(lock, ww_ctx);
- raw_spin_unlock(&lock->wait_lock);
+ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
return 0;
}
+ BUG_ON(arch_irqs_disabled_flags(flags));

set_current_state(state);

@@ -1172,7 +1173,7 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
*/
fixup_rt_mutex_waiters(lock);

- raw_spin_unlock(&lock->wait_lock);
+ raw_spin_unlock_irq(&lock->wait_lock);

/* Remove pending timer: */
if (unlikely(timeout))
@@ -1189,9 +1190,10 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
static inline int
rt_mutex_slowtrylock(struct rt_mutex *lock)
{
+ unsigned long flags;
int ret = 0;

- raw_spin_lock(&lock->wait_lock);
+ raw_spin_lock_irqsave(&lock->wait_lock, flags);
init_lists(lock);

if (likely(rt_mutex_owner(lock) != current)) {
@@ -1204,7 +1206,7 @@ rt_mutex_slowtrylock(struct rt_mutex *lock)
fixup_rt_mutex_waiters(lock);
}

- raw_spin_unlock(&lock->wait_lock);
+ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);

return ret;
}
@@ -1215,7 +1217,9 @@ rt_mutex_slowtrylock(struct rt_mutex *lock)
static void __sched
rt_mutex_slowunlock(struct rt_mutex *lock)
{
- raw_spin_lock(&lock->wait_lock);
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&lock->wait_lock, flags);

debug_rt_mutex_unlock(lock);

@@ -1223,13 +1227,13 @@ rt_mutex_slowunlock(struct rt_mutex *lock)

if (!rt_mutex_has_waiters(lock)) {
lock->owner = NULL;
- raw_spin_unlock(&lock->wait_lock);
+ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
return;
}

wakeup_next_waiter(lock);

- raw_spin_unlock(&lock->wait_lock);
+ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);

/* Undo pi boosting if necessary: */
rt_mutex_adjust_prio(current);
@@ -1489,10 +1493,10 @@ int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
{
int ret;

- raw_spin_lock(&lock->wait_lock);
+ raw_spin_lock_irq(&lock->wait_lock);

if (try_to_take_rt_mutex(lock, task, NULL)) {
- raw_spin_unlock(&lock->wait_lock);
+ raw_spin_unlock_irq(&lock->wait_lock);
return 1;
}

@@ -1515,18 +1519,17 @@ int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
* PI_REQUEUE_INPROGRESS, so that if the task is waking up
* it will know that we are in the process of requeuing it.
*/
- raw_spin_lock_irq(&task->pi_lock);
+ raw_spin_lock(&task->pi_lock);
if (task->pi_blocked_on) {
- raw_spin_unlock_irq(&task->pi_lock);
- raw_spin_unlock(&lock->wait_lock);
+ raw_spin_unlock(&task->pi_lock);
+ raw_spin_unlock_irq(&lock->wait_lock);
return -EAGAIN;
}
task->pi_blocked_on = PI_REQUEUE_INPROGRESS;
- raw_spin_unlock_irq(&task->pi_lock);
+ raw_spin_unlock(&task->pi_lock);
#endif

ret = task_blocks_on_rt_mutex(lock, waiter, task, detect_deadlock);
-
if (ret && !rt_mutex_owner(lock)) {
/*
* Reset the return value. We might have
@@ -1540,7 +1543,7 @@ int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
if (unlikely(ret))
remove_waiter(lock, waiter);

- raw_spin_unlock(&lock->wait_lock);
+ raw_spin_unlock_irq(&lock->wait_lock);

debug_rt_mutex_print_deadlock(waiter);

@@ -1590,12 +1593,11 @@ int rt_mutex_finish_proxy_lock(struct rt_mutex *lock,
{
int ret;

- raw_spin_lock(&lock->wait_lock);
+ raw_spin_lock_irq(&lock->wait_lock);

set_current_state(TASK_INTERRUPTIBLE);

ret = __rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, to, waiter, NULL);
-
set_current_state(TASK_RUNNING);

if (unlikely(ret))
@@ -1607,7 +1609,7 @@ int rt_mutex_finish_proxy_lock(struct rt_mutex *lock,
*/
fixup_rt_mutex_waiters(lock);

- raw_spin_unlock(&lock->wait_lock);
+ raw_spin_unlock_irq(&lock->wait_lock);

return ret;
}
diff --git a/localversion-rt b/localversion-rt
index 6f206be..c3054d0 100644
--- a/localversion-rt
+++ b/localversion-rt
@@ -1 +1 @@
--rt1
+-rt2
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majo...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

[Pavel Vasilyev]

16.11.2013 23:46, Sebastian Andrzej Siewior пишет:

> Dear RT folks!
>
> I'm pleased to announce the v3.12.0-rt2 patch set.

I cat't still to mount filesystems!
bash not start!

1. pull git kernel 3.12
2. wget rt-patch
3. patch'em all
4. make oldconfig && make && make install
5 In cmdline type init=/bin/bash
....
And.... see screenshot:
http://i59.fastpic.ru/big/2013/1117/85/61c0a35e5a456263910ce4cf3152d085.jpg

system not response, SysRQ+B - work


3.2.52-rt72 - work
3.10.18-rt14 - work
3.12-rt2 - NO!





--

Pavel.

[Pavel Vasilyev]

Fine, killed 3.12 now decided to finish 3.2.x. Good job guys!

Not configuration, not hardware, not software has not been updated or changed.

BUG: scheduling while atomic: irq/74-sata_nv/57/0x00000002
Modules linked in: cls_u32 sch_sfq sch_htb
Pid: 57, comm: irq/74-sata_nv Tainted: G O 3.2.52-rt73 #10
Call Trace:
[<ffffffff814bdef4>] ? __schedule+0x314/0x344
[<ffffffff81081b77>] ? task_blocks_on_rt_mutex+0x1e7/0x280
[<ffffffff814be741>] ? schedule+0x21/0xa0
[<ffffffff814c0d88>] ? rt_spin_lock_slowlock+0x128/0x280
[<ffffffff81204d01>] ? blk_update_request+0x11/0x450
[<ffffffff812a6976>] ? add_timer_randomness+0x86/0x1e0
[<ffffffff81206eac>] ? blk_end_request+0x9c/0xc0
[<ffffffff812c629a>] ? scsi_io_completion+0x9a/0x770
[<ffffffff8120d4ab>] ? blk_done_softirq+0x6b/0x80
[<ffffffff8104a805>] ? __do_softirq_common+0xa5/0x1d0
[<ffffffff81094ec0>] ? irq_thread_fn+0x50/0x50
[<ffffffff8104ad77>] ? local_bh_enable+0x127/0x150
[<ffffffff81094f08>] ? irq_forced_thread_fn+0x48/0x70
[<ffffffff81094d80>] ? irq_thread+0x150/0x240
[<ffffffff81094c30>] ? disable_irq_nosync+0x60/0x60
[<ffffffff81067150>] ? kthread+0x80/0x90
[<ffffffff814c3174>] ? kernel_thread_helper+0x4/0x10
[<ffffffff810670d0>] ? kthread_bind+0x80/0x80
[<ffffffff814c3170>] ? gs_change+0xb/0xb


BUG: scheduling while atomic: ksoftirqd/3/27/0x00000002
Pid: 3, comm: ksoftirqd/0 Tainted: G O 3.2.52-rt73 #10
...
BUG: scheduling while atomic: ksoftirqd/0/3/0x00000002
Pid: 27, comm: ksoftirqd/3 Tainted: G O 3.2.52-rt73 #10
....
BUG: scheduling while atomic: ksoftirqd/0/3/0x00000002
Pid: 27, comm: ksoftirqd/3 Tainted: G O 3.2.52-rt73 #10



--

Pavel.

[Sebastian Andrzej Siewior]

* Pavel Vasilyev | 2013-11-22 00:44:37 [+0400]:

>
>Fine, killed 3.12 now decided to finish 3.2.x. Good job guys!
>
>Not configuration, not hardware, not software has not been updated or changed.

No I am a bit confused. On 16th you write:
|3.2.52-rt72 - work

and now you say that we killed v3.2. There was no v3.2.52-rt72 but
v3.2.51-rt72. So did -rt72 work and -rt73 does no more?

I saw your earlier screenshots and there is nothing I can say. I can't
tell based on the screenshot what is wrong. Sorry.

This time you managed to include a backtrace. Better! However would you
mind to enable frame pointers? The backtrace

>BUG: scheduling while atomic: irq/74-sata_nv/57/0x00000002
>Modules linked in: cls_u32 sch_sfq sch_htb
>Pid: 57, comm: irq/74-sata_nv Tainted: G O 3.2.52-rt73 #10
>Call Trace:
> [<ffffffff814bdef4>] ? __schedule+0x314/0x344
> [<ffffffff81081b77>] ? task_blocks_on_rt_mutex+0x1e7/0x280
> [<ffffffff814be741>] ? schedule+0x21/0xa0
> [<ffffffff814c0d88>] ? rt_spin_lock_slowlock+0x128/0x280
> [<ffffffff81204d01>] ? blk_update_request+0x11/0x450
> [<ffffffff812a6976>] ? add_timer_randomness+0x86/0x1e0
> [<ffffffff81206eac>] ? blk_end_request+0x9c/0xc0
> [<ffffffff812c629a>] ? scsi_io_completion+0x9a/0x770
> [<ffffffff8120d4ab>] ? blk_done_softirq+0x6b/0x80
> [<ffffffff8104a805>] ? __do_softirq_common+0xa5/0x1d0
> [<ffffffff81094ec0>] ? irq_thread_fn+0x50/0x50
> [<ffffffff8104ad77>] ? local_bh_enable+0x127/0x150
> [<ffffffff81094f08>] ? irq_forced_thread_fn+0x48/0x70
> [<ffffffff81094d80>] ? irq_thread+0x150/0x240
> [<ffffffff81094c30>] ? disable_irq_nosync+0x60/0x60
> [<ffffffff81067150>] ? kthread+0x80/0x90
> [<ffffffff814c3174>] ? kernel_thread_helper+0x4/0x10
> [<ffffffff810670d0>] ? kthread_bind+0x80/0x80
> [<ffffffff814c3170>] ? gs_change+0xb/0xb

shows now random functions which were on stack before the accident. What
happens is that something on the system tries to take a sleeping long
while beeing most likely in a preempt disable region. With lockdep on it
might even throw some additional information here.

Sebastian

[Sebastian Andrzej Siewior]

Dear RT folks!

I'm pleased to announce the v3.12.1-rt4 patch set.

Changes since v3.12.0-rt2
- rtmutex: the patch with the conversion to raw_spinlock_irq() of the
waiter lock has been replaced by a trylock attempt this keeps the
change a lot smaller. Initially suggested by Matt Cowell.
There is also a special unlock function so lockdep does not complain
on the in unlock path.
- A patch from Peter Zijlstra so lockdep sees the locking problem from
above.
- migrate_disable() does not invoke preempt_enable() +
preempt_disable() on recursion. An optimisation by Nicholas Mc Guire.
- rt_mutex_trylock() does not invoke migrate_disable() +
migrate_enable() in the case where it did not get the lock. An
optimisation by Nicholas Mc Guire.

Known issues:

- bcache is disabled.

- an ancient race (since we got sleeping spinlocks) where the
TASK_TRACED state is temporary replaced while waiting on a rw
lock and the task can't be traced.

The delta patch against v3.12.1-rt3 is appended below and can be found
here:
https://www.kernel.org/pub/linux/kernel/projects/rt/3.12/incr/patch-3.12.1-rt3-rt4.patch.xz

The RT patch against 3.12.1 can be found here:

https://www.kernel.org/pub/linux/kernel/projects/rt/3.12/patch-3.12.1-rt4.patch.xz

The split quilt queue is available at:

https://www.kernel.org/pub/linux/kernel/projects/rt/3.12/patches-3.12.1-rt4.tar.xz

Sebastian

diff --git a/include/linux/spinlock_rt.h b/include/linux/spinlock_rt.h
index 0618387..b3c504b 100644
--- a/include/linux/spinlock_rt.h
+++ b/include/linux/spinlock_rt.h
@@ -22,6 +22,7 @@ extern void __lockfunc rt_spin_lock(spinlock_t *lock);
extern unsigned long __lockfunc rt_spin_lock_trace_flags(spinlock_t *lock);
extern void __lockfunc rt_spin_lock_nested(spinlock_t *lock, int subclass);
extern void __lockfunc rt_spin_unlock(spinlock_t *lock);
+extern void __lockfunc rt_spin_unlock_after_trylock_in_irq(spinlock_t *lock);
extern void __lockfunc rt_spin_unlock_wait(spinlock_t *lock);
extern int __lockfunc rt_spin_trylock_irqsave(spinlock_t *lock, unsigned long *flags);
extern int __lockfunc rt_spin_trylock_bh(spinlock_t *lock);
diff --git a/kernel/futex.c b/kernel/futex.c
index 404d0bd..0ef419d 100644

--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -891,7 +891,7 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this)
if (pi_state->owner != current)
return -EINVAL;

- raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock);
+ raw_spin_lock(&pi_state->pi_mutex.wait_lock);

new_owner = rt_mutex_next_owner(&pi_state->pi_mutex);

/*
@@ -917,21 +917,21 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this)
else if (curval != uval)
ret = -EINVAL;
if (ret) {

- raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock);
+ raw_spin_unlock(&pi_state->pi_mutex.wait_lock);
return ret;
}
}

- raw_spin_lock(&pi_state->owner->pi_lock);
+ raw_spin_lock_irq(&pi_state->owner->pi_lock);
WARN_ON(list_empty(&pi_state->list));
list_del_init(&pi_state->list);
- raw_spin_unlock(&pi_state->owner->pi_lock);
+ raw_spin_unlock_irq(&pi_state->owner->pi_lock);

- raw_spin_lock(&new_owner->pi_lock);
+ raw_spin_lock_irq(&new_owner->pi_lock);

WARN_ON(!list_empty(&pi_state->list));
list_add(&pi_state->list, &new_owner->pi_state_list);
pi_state->owner = new_owner;

- raw_spin_unlock(&new_owner->pi_lock);
+ raw_spin_unlock_irq(&new_owner->pi_lock);

raw_spin_unlock(&pi_state->pi_mutex.wait_lock);
rt_mutex_unlock(&pi_state->pi_mutex);
@@ -1762,11 +1762,11 @@ static int fixup_owner(u32 __user *uaddr, struct futex_q *q, int locked)
* we returned due to timeout or signal without taking the
* rt_mutex. Too late.
*/

- raw_spin_lock_irq(&q->pi_state->pi_mutex.wait_lock);
+ raw_spin_lock(&q->pi_state->pi_mutex.wait_lock);

owner = rt_mutex_owner(&q->pi_state->pi_mutex);
if (!owner)
owner = rt_mutex_next_owner(&q->pi_state->pi_mutex);

- raw_spin_unlock_irq(&q->pi_state->pi_mutex.wait_lock);
+ raw_spin_unlock(&q->pi_state->pi_mutex.wait_lock);

ret = fixup_pi_state_owner(uaddr, q, owner);
goto out;
}

diff --git a/kernel/rt.c b/kernel/rt.c
index 433ae42..4b2c4a9 100644
--- a/kernel/rt.c
+++ b/kernel/rt.c
@@ -182,11 +182,10 @@ int __lockfunc rt_write_trylock(rwlock_t *rwlock)
{
int ret = rt_mutex_trylock(&rwlock->lock);

- migrate_disable();
- if (ret)
+ if (ret) {
rwlock_acquire(&rwlock->dep_map, 0, 1, _RET_IP_);
- else
- migrate_enable();
+ migrate_disable();
+ }

return ret;
}
diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c
index c2f3f63..4e9691f 100644

--- a/kernel/rtmutex.c
+++ b/kernel/rtmutex.c
@@ -298,7 +298,7 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
plist_add(&waiter->list_entry, &lock->wait_list);

/* Release the task */

- raw_spin_unlock(&task->pi_lock);
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);

if (!rt_mutex_owner(lock)) {
struct rt_mutex_waiter *lock_top_waiter;

@@ -309,7 +309,7 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
lock_top_waiter = rt_mutex_top_waiter(lock);
if (top_waiter != lock_top_waiter)
rt_mutex_wake_waiter(lock_top_waiter);

- raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+ raw_spin_unlock(&lock->wait_lock);

goto out_put_task;
}
put_task_struct(task);
@@ -317,7 +317,7 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
/* Grab the next task */
task = rt_mutex_owner(lock);
get_task_struct(task);

- raw_spin_lock(&task->pi_lock);
+ raw_spin_lock_irqsave(&task->pi_lock, flags);

if (waiter == rt_mutex_top_waiter(lock)) {
/* Boost the owner */
@@ -335,10 +335,10 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
__rt_mutex_adjust_prio(task);
}

- raw_spin_unlock(&task->pi_lock);
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);

top_waiter = rt_mutex_top_waiter(lock);
- raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+ raw_spin_unlock(&lock->wait_lock);

if (!detect_deadlock && waiter != top_waiter)
goto out_put_task;

@@ -425,9 +425,10 @@ __try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,

/* We got the lock. */

if (waiter || rt_mutex_has_waiters(lock)) {

+ unsigned long flags;
struct rt_mutex_waiter *top;

- raw_spin_lock(&task->pi_lock);
+ raw_spin_lock_irqsave(&task->pi_lock, flags);

/* remove the queued waiter. */
if (waiter) {

@@ -444,7 +445,7 @@ __try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,

top->pi_list_entry.prio = top->list_entry.prio;
plist_add(&top->pi_list_entry, &task->pi_waiters);
}

- raw_spin_unlock(&task->pi_lock);
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
}

debug_rt_mutex_lock(lock);
@@ -477,9 +478,10 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,

{
struct task_struct *owner = rt_mutex_owner(lock);
struct rt_mutex_waiter *top_waiter = waiter;

+ unsigned long flags;

int chain_walk = 0, res;

- raw_spin_lock(&task->pi_lock);
+ raw_spin_lock_irqsave(&task->pi_lock, flags);

/*
* In the case of futex requeue PI, this will be a proxy

@@ -491,7 +493,7 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,

* the task if PI_WAKEUP_INPROGRESS is set.
*/
if (task != current && task->pi_blocked_on == PI_WAKEUP_INPROGRESS) {

- raw_spin_unlock(&task->pi_lock);
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
return -EAGAIN;
}

@@ -510,20 +512,20 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,

task->pi_blocked_on = waiter;

- raw_spin_unlock(&task->pi_lock);
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);

if (!owner)
return 0;

if (waiter == rt_mutex_top_waiter(lock)) {

- raw_spin_lock(&owner->pi_lock);
+ raw_spin_lock_irqsave(&owner->pi_lock, flags);

plist_del(&top_waiter->pi_list_entry, &owner->pi_waiters);
plist_add(&waiter->pi_list_entry, &owner->pi_waiters);

__rt_mutex_adjust_prio(owner);
if (rt_mutex_real_waiter(owner->pi_blocked_on))
chain_walk = 1;

- raw_spin_unlock(&owner->pi_lock);
+ raw_spin_unlock_irqrestore(&owner->pi_lock, flags);

}
else if (debug_rt_mutex_detect_deadlock(waiter, detect_deadlock))
chain_walk = 1;

@@ -538,12 +540,12 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
*/
get_task_struct(owner);

- raw_spin_unlock_irq(&lock->wait_lock);
+ raw_spin_unlock(&lock->wait_lock);

res = rt_mutex_adjust_prio_chain(owner, detect_deadlock, lock, waiter,
task);

- raw_spin_lock_irq(&lock->wait_lock);
+ raw_spin_lock(&lock->wait_lock);

return res;
}
@@ -558,8 +560,9 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,

static void wakeup_next_waiter(struct rt_mutex *lock)
{
struct rt_mutex_waiter *waiter;

+ unsigned long flags;

- raw_spin_lock(&current->pi_lock);
+ raw_spin_lock_irqsave(&current->pi_lock, flags);

waiter = rt_mutex_top_waiter(lock);

@@ -573,7 +576,7 @@ static void wakeup_next_waiter(struct rt_mutex *lock)

rt_mutex_set_owner(lock, NULL);

- raw_spin_unlock(&current->pi_lock);
+ raw_spin_unlock_irqrestore(&current->pi_lock, flags);

rt_mutex_wake_waiter(waiter);
}
@@ -589,19 +592,20 @@ static void remove_waiter(struct rt_mutex *lock,

{
int first = (waiter == rt_mutex_top_waiter(lock));
struct task_struct *owner = rt_mutex_owner(lock);

+ unsigned long flags;
int chain_walk = 0;

- raw_spin_lock(&current->pi_lock);
+ raw_spin_lock_irqsave(&current->pi_lock, flags);

plist_del(&waiter->list_entry, &lock->wait_list);
current->pi_blocked_on = NULL;

- raw_spin_unlock(&current->pi_lock);
+ raw_spin_unlock_irqrestore(&current->pi_lock, flags);

if (!owner)
return;

if (first) {

- raw_spin_lock(&owner->pi_lock);
+ raw_spin_lock_irqsave(&owner->pi_lock, flags);

plist_del(&waiter->pi_list_entry, &owner->pi_waiters);

@@ -616,7 +620,7 @@ static void remove_waiter(struct rt_mutex *lock,

if (rt_mutex_real_waiter(owner->pi_blocked_on))
chain_walk = 1;

- raw_spin_unlock(&owner->pi_lock);
+ raw_spin_unlock_irqrestore(&owner->pi_lock, flags);
}

WARN_ON(!plist_node_empty(&waiter->pi_list_entry));
@@ -627,11 +631,11 @@ static void remove_waiter(struct rt_mutex *lock,

/* gets dropped in rt_mutex_adjust_prio_chain()! */
get_task_struct(owner);

- raw_spin_unlock_irq(&lock->wait_lock);
+ raw_spin_unlock(&lock->wait_lock);

rt_mutex_adjust_prio_chain(owner, 0, lock, NULL, current);

- raw_spin_lock_irq(&lock->wait_lock);
+ raw_spin_lock(&lock->wait_lock);
}

/*
@@ -719,6 +723,9 @@ static int adaptive_wait(struct rt_mutex *lock,
}
#endif

+# define pi_lock(lock) raw_spin_lock_irq(lock)
+# define pi_unlock(lock) raw_spin_unlock_irq(lock)
+

/*
* Slow path lock function spin_lock style: this variant is very
* careful not to miss any non-lock wakeups.

@@ -730,22 +737,19 @@ static void noinline __sched rt_spin_lock_slowlock(struct rt_mutex *lock)

{
struct task_struct *lock_owner, *self = current;
struct rt_mutex_waiter waiter, *top_waiter;

- unsigned long flags;
int ret;

rt_mutex_init_waiter(&waiter, true);

- raw_local_save_flags(flags);
- raw_spin_lock_irq(&lock->wait_lock);
+ raw_spin_lock(&lock->wait_lock);

init_lists(lock);

if (__try_to_take_rt_mutex(lock, self, NULL, STEAL_LATERAL)) {

- raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+ raw_spin_unlock(&lock->wait_lock);
return;
}

BUG_ON(rt_mutex_owner(lock) == self);
- BUG_ON(arch_irqs_disabled_flags(flags));

/*
* We save whatever state the task is in and we'll restore it

@@ -753,10 +757,10 @@ static void noinline __sched rt_spin_lock_slowlock(struct rt_mutex *lock)

* as well. We are serialized via pi_lock against wakeups. See
* try_to_wake_up().
*/

- raw_spin_lock(&self->pi_lock);
+ pi_lock(&self->pi_lock);

self->saved_state = self->state;
__set_current_state(TASK_UNINTERRUPTIBLE);

- raw_spin_unlock(&self->pi_lock);
+ pi_unlock(&self->pi_lock);

ret = task_blocks_on_rt_mutex(lock, &waiter, self, 0);
BUG_ON(ret);

@@ -769,18 +773,18 @@ static void noinline __sched rt_spin_lock_slowlock(struct rt_mutex *lock)

top_waiter = rt_mutex_top_waiter(lock);
lock_owner = rt_mutex_owner(lock);

- raw_spin_unlock_irq(&lock->wait_lock);
+ raw_spin_unlock(&lock->wait_lock);

debug_rt_mutex_print_deadlock(&waiter);

if (top_waiter != &waiter || adaptive_wait(lock, lock_owner))
schedule_rt_mutex(lock);

- raw_spin_lock_irq(&lock->wait_lock);
+ raw_spin_lock(&lock->wait_lock);

- raw_spin_lock(&self->pi_lock);
+ pi_lock(&self->pi_lock);
__set_current_state(TASK_UNINTERRUPTIBLE);
- raw_spin_unlock(&self->pi_lock);
+ pi_unlock(&self->pi_lock);
}

/*
@@ -790,10 +794,10 @@ static void noinline __sched rt_spin_lock_slowlock(struct rt_mutex *lock)

* happened while we were blocked. Clear saved_state so
* try_to_wakeup() does not get confused.
*/

- raw_spin_lock(&self->pi_lock);
+ pi_lock(&self->pi_lock);

__set_current_state(self->saved_state);
self->saved_state = TASK_RUNNING;

- raw_spin_unlock(&self->pi_lock);
+ pi_unlock(&self->pi_lock);

/*
* try_to_take_rt_mutex() sets the waiter bit

@@ -804,7 +808,7 @@ static void noinline __sched rt_spin_lock_slowlock(struct rt_mutex *lock)

BUG_ON(rt_mutex_has_waiters(lock) && &waiter == rt_mutex_top_waiter(lock));
BUG_ON(!plist_node_empty(&waiter.list_entry));

- raw_spin_unlock_irq(&lock->wait_lock);
+ raw_spin_unlock(&lock->wait_lock);

debug_rt_mutex_free_waiter(&waiter);
}
@@ -812,30 +816,43 @@ static void noinline __sched rt_spin_lock_slowlock(struct rt_mutex *lock)
/*
* Slow path to release a rt_mutex spin_lock style
*/
-static void noinline __sched rt_spin_lock_slowunlock(struct rt_mutex *lock)
+static void __sched __rt_spin_lock_slowunlock(struct rt_mutex *lock)
{

- unsigned long flags;
-

- raw_spin_lock_irqsave(&lock->wait_lock, flags);
-
debug_rt_mutex_unlock(lock);

rt_mutex_deadlock_account_unlock(current);

if (!rt_mutex_has_waiters(lock)) {
lock->owner = NULL;

- raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+ raw_spin_unlock(&lock->wait_lock);
return;
}

wakeup_next_waiter(lock);

- raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+ raw_spin_unlock(&lock->wait_lock);

/* Undo pi boosting.when necessary */
rt_mutex_adjust_prio(current);
}

+static void noinline __sched rt_spin_lock_slowunlock(struct rt_mutex *lock)
+{
+ raw_spin_lock(&lock->wait_lock);
+ __rt_spin_lock_slowunlock(lock);
+}
+
+static void noinline __sched rt_spin_lock_slowunlock_hirq(struct rt_mutex *lock)
+{
+ int ret;
+
+ do {
+ ret = raw_spin_trylock(&lock->wait_lock);
+ } while (!ret);
+
+ __rt_spin_lock_slowunlock(lock);
+}
+
void __lockfunc rt_spin_lock(spinlock_t *lock)
{
rt_spin_lock_fastlock(&lock->lock, rt_spin_lock_slowlock);
@@ -866,6 +883,13 @@ void __lockfunc rt_spin_unlock(spinlock_t *lock)
}
EXPORT_SYMBOL(rt_spin_unlock);

+void __lockfunc rt_spin_unlock_after_trylock_in_irq(spinlock_t *lock)
+{
+ /* NOTE: we always pass in '1' for nested, for simplicity */
+ spin_release(&lock->dep_map, 1, _RET_IP_);
+ rt_spin_lock_fastunlock(&lock->lock, rt_spin_lock_slowunlock_hirq);
+}
+
void __lockfunc __rt_spin_unlock(struct rt_mutex *lock)
{
rt_spin_lock_fastunlock(lock, rt_spin_lock_slowunlock);
@@ -1030,13 +1054,13 @@ __rt_mutex_slowlock(struct rt_mutex *lock, int state,
break;
}

- raw_spin_unlock_irq(&lock->wait_lock);
+ raw_spin_unlock(&lock->wait_lock);

debug_rt_mutex_print_deadlock(waiter);

schedule_rt_mutex(lock);

- raw_spin_lock_irq(&lock->wait_lock);
+ raw_spin_lock(&lock->wait_lock);
set_current_state(state);
}

@@ -1128,23 +1152,20 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,

int detect_deadlock, struct ww_acquire_ctx *ww_ctx)
{
struct rt_mutex_waiter waiter;

- unsigned long flags;

int ret = 0;

rt_mutex_init_waiter(&waiter, false);

- raw_local_save_flags(flags);
- raw_spin_lock_irq(&lock->wait_lock);
+ raw_spin_lock(&lock->wait_lock);

init_lists(lock);

/* Try to acquire the lock again: */
if (try_to_take_rt_mutex(lock, current, NULL)) {
if (ww_ctx)
ww_mutex_account_lock(lock, ww_ctx);

- raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+ raw_spin_unlock(&lock->wait_lock);
return 0;
}
- BUG_ON(arch_irqs_disabled_flags(flags));

set_current_state(state);

@@ -1173,7 +1194,7 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
*/
fixup_rt_mutex_waiters(lock);

- raw_spin_unlock_irq(&lock->wait_lock);
+ raw_spin_unlock(&lock->wait_lock);

/* Remove pending timer: */
if (unlikely(timeout))

@@ -1190,10 +1211,10 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,

static inline int
rt_mutex_slowtrylock(struct rt_mutex *lock)
{

- unsigned long flags;
int ret = 0;

- raw_spin_lock_irqsave(&lock->wait_lock, flags);
+ if (!raw_spin_trylock(&lock->wait_lock))
+ return ret;

init_lists(lock);

if (likely(rt_mutex_owner(lock) != current)) {

@@ -1206,7 +1227,7 @@ rt_mutex_slowtrylock(struct rt_mutex *lock)
fixup_rt_mutex_waiters(lock);
}

- raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+ raw_spin_unlock(&lock->wait_lock);

return ret;
}
@@ -1217,9 +1238,7 @@ rt_mutex_slowtrylock(struct rt_mutex *lock)

static void __sched
rt_mutex_slowunlock(struct rt_mutex *lock)
{

- unsigned long flags;
-
- raw_spin_lock_irqsave(&lock->wait_lock, flags);
+ raw_spin_lock(&lock->wait_lock);

debug_rt_mutex_unlock(lock);

@@ -1227,13 +1246,13 @@ rt_mutex_slowunlock(struct rt_mutex *lock)

if (!rt_mutex_has_waiters(lock)) {
lock->owner = NULL;

- raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+ raw_spin_unlock(&lock->wait_lock);
return;
}

wakeup_next_waiter(lock);

- raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+ raw_spin_unlock(&lock->wait_lock);

/* Undo pi boosting if necessary: */
rt_mutex_adjust_prio(current);

@@ -1493,10 +1512,10 @@ int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
{
int ret;

- raw_spin_lock_irq(&lock->wait_lock);
+ raw_spin_lock(&lock->wait_lock);

if (try_to_take_rt_mutex(lock, task, NULL)) {
- raw_spin_unlock_irq(&lock->wait_lock);
+ raw_spin_unlock(&lock->wait_lock);
return 1;
}

@@ -1519,17 +1538,18 @@ int rt_mutex_start_proxy_lock(struct rt_mutex *lock,

* PI_REQUEUE_INPROGRESS, so that if the task is waking up
* it will know that we are in the process of requeuing it.
*/

- raw_spin_lock(&task->pi_lock);
+ raw_spin_lock_irq(&task->pi_lock);
if (task->pi_blocked_on) {
- raw_spin_unlock(&task->pi_lock);
- raw_spin_unlock_irq(&lock->wait_lock);
+ raw_spin_unlock_irq(&task->pi_lock);
+ raw_spin_unlock(&lock->wait_lock);

return -EAGAIN;
}
task->pi_blocked_on = PI_REQUEUE_INPROGRESS;

- raw_spin_unlock(&task->pi_lock);
+ raw_spin_unlock_irq(&task->pi_lock);

#endif

ret = task_blocks_on_rt_mutex(lock, waiter, task, detect_deadlock);

+

if (ret && !rt_mutex_owner(lock)) {
/*
* Reset the return value. We might have

@@ -1543,7 +1563,7 @@ int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
if (unlikely(ret))
remove_waiter(lock, waiter);

- raw_spin_unlock_irq(&lock->wait_lock);
+ raw_spin_unlock(&lock->wait_lock);

debug_rt_mutex_print_deadlock(waiter);

@@ -1593,11 +1613,12 @@ int rt_mutex_finish_proxy_lock(struct rt_mutex *lock,
{
int ret;

- raw_spin_lock_irq(&lock->wait_lock);
+ raw_spin_lock(&lock->wait_lock);

set_current_state(TASK_INTERRUPTIBLE);

ret = __rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, to, waiter, NULL);

+
set_current_state(TASK_RUNNING);

if (unlikely(ret))
@@ -1609,7 +1630,7 @@ int rt_mutex_finish_proxy_lock(struct rt_mutex *lock,
*/
fixup_rt_mutex_waiters(lock);

- raw_spin_unlock_irq(&lock->wait_lock);
+ raw_spin_unlock(&lock->wait_lock);

return ret;
}
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index a7fafc28..22fa2e2 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2418,13 +2418,12 @@ void migrate_disable(void)
}
#endif

- preempt_disable();
if (p->migrate_disable) {
p->migrate_disable++;
- preempt_enable();
return;
}

+ preempt_disable();
preempt_lazy_disable();
pin_current_cpu();
p->migrate_disable = 1;
@@ -2454,13 +2453,12 @@ void migrate_enable(void)
#endif
WARN_ON_ONCE(p->migrate_disable <= 0);

- preempt_disable();
if (migrate_disable_count(p) > 1) {
p->migrate_disable--;
- preempt_enable();
return;
}

+ preempt_disable();
if (unlikely(migrate_disabled_updated(p))) {
/*
* Undo whatever update_migrate_disable() did, also see there
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 6c99698..9a7268f 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -354,13 +354,51 @@ EXPORT_SYMBOL(local_bh_enable_ip);
#define MAX_SOFTIRQ_TIME msecs_to_jiffies(2)
#define MAX_SOFTIRQ_RESTART 10

+#ifdef CONFIG_TRACE_IRQFLAGS
+/*
+ * Convoluted means of passing __do_softirq() a message through the various
+ * architecture execute_on_stack() bits.
+ *
+ * When we run softirqs from irq_exit() and thus on the hardirq stack we need
+ * to keep the lockdep irq context tracking as tight as possible in order to
+ * not miss-qualify lock contexts and miss possible deadlocks.
+ */
+static DEFINE_PER_CPU(int, softirq_from_hardirq);
+
+static inline void lockdep_softirq_from_hardirq(void)
+{
+ this_cpu_write(softirq_from_hardirq, 1);
+}
+
+static inline void lockdep_softirq_start(void)
+{
+ if (this_cpu_read(softirq_from_hardirq))
+ trace_hardirq_exit();
+ lockdep_softirq_enter();
+}
+
+static inline void lockdep_softirq_end(void)
+{
+ lockdep_softirq_exit();
+ if (this_cpu_read(softirq_from_hardirq)) {
+ this_cpu_write(softirq_from_hardirq, 0);
+ trace_hardirq_enter();
+ }
+}
+
+#else
+static inline void lockdep_softirq_from_hardirq(void) { }
+static inline void lockdep_softirq_start(void) { }
+static inline void lockdep_softirq_end(void) { }
+#endif
+
asmlinkage void __do_softirq(void)
{
- __u32 pending;
unsigned long end = jiffies + MAX_SOFTIRQ_TIME;
- int cpu;
unsigned long old_flags = current->flags;
int max_restart = MAX_SOFTIRQ_RESTART;
+ __u32 pending;
+ int cpu;

/*
* Mask out PF_MEMALLOC s current task context is borrowed for the
@@ -373,7 +411,7 @@ asmlinkage void __do_softirq(void)
account_irq_enter_time(current);

__local_bh_disable(_RET_IP_, SOFTIRQ_OFFSET);
- lockdep_softirq_enter();
+ lockdep_softirq_start();

cpu = smp_processor_id();
restart:
@@ -391,8 +429,7 @@ asmlinkage void __do_softirq(void)
wakeup_softirqd();
}

- lockdep_softirq_exit();
-
+ lockdep_softirq_end();
account_irq_exit_time(current);
__local_bh_enable(SOFTIRQ_OFFSET);
tsk_restore_flags(current, old_flags, PF_MEMALLOC);
@@ -698,6 +735,7 @@ static inline void invoke_softirq(void)
{
#ifndef CONFIG_PREEMPT_RT_FULL
if (!force_irqthreads) {
+ lockdep_softirq_from_hardirq();
/*
* We can safely execute softirq on the current stack if
* it is the irq stack, because it should be near empty
@@ -746,13 +784,13 @@ void irq_exit(void)
#endif

account_irq_exit_time(current);
- trace_hardirq_exit();
sub_preempt_count(HARDIRQ_OFFSET);
if (!in_interrupt() && local_softirq_pending())
invoke_softirq();

tick_irq_exit();
rcu_irq_exit();
+ trace_hardirq_exit(); /* must be last! */
}

void raise_softirq(unsigned int nr)
diff --git a/kernel/timer.c b/kernel/timer.c
index fa4a92a..b06c647 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1400,7 +1400,7 @@ unsigned long get_next_timer_interrupt(unsigned long now)
expires = base->next_timer;
}
#ifdef CONFIG_PREEMPT_RT_FULL
- rt_spin_unlock(&base->lock);
+ rt_spin_unlock_after_trylock_in_irq(&base->lock);
#else
spin_unlock(&base->lock);
#endif
diff --git a/localversion-rt b/localversion-rt
index 1445cd6..ad3da1b 100644

--- a/localversion-rt
+++ b/localversion-rt
@@ -1 +1 @@

--rt3
+-rt4

[Pavel Vasilyev]

------------[ cut here ]------------
WARNING: CPU: 1 PID: 10 at kernel/time/tick-sched.c:191 0xffffffff8107bac6()
NO_HZ FULL will not work with unstable sched clock
Modules linked in:
CPU: 1 PID: 10 Comm: rcuop/0 Not tainted 3.12.2-rt4 #3
Hardware name: TYAN Computer Corp. S2895/S2895, BIOS 2004Q3 11/18/2008
0000000000000009 ffff88027fc83ea8 ffffffff81501a58 0000000000000039
ffff88027fc83ef8 ffff88027fc83ee8 ffffffff8102f992 0000000000012700
ata3.00: configured for UDMA/100
ffff88027fc8d580 0000000000000001 ffff880272894020 ffff88027fc0d700
Call Trace:
<IRQ> [<ffffffff81501a58>] 0xffffffff81501a58
[<ffffffff8102f992>] 0xffffffff8102f992
[<ffffffff8102fa61>] 0xffffffff8102fa61
[<ffffffff8107bac6>] 0xffffffff8107bac6
[<ffffffff8107c8f4>] 0xffffffff8107c8f4
[<ffffffff8103405d>] 0xffffffff8103405d
[<ffffffff81006fff>] 0xffffffff81006fff
[<ffffffff815085f7>] 0xffffffff815085f7
<EOI> [<ffffffff81007083>] ? 0xffffffff81007083
[<ffffffff81506865>] ? 0xffffffff81506865
[<ffffffff81095961>] ? 0xffffffff81095961
[<ffffffff81095860>] ? 0xffffffff81095860
[<ffffffff8104d0dd>] 0xffffffff8104d0dd
[<ffffffff8104d030>] ? 0xffffffff8104d030
[<ffffffff8150763c>] 0xffffffff8150763c
[<ffffffff8104d030>] ? 0xffffffff8104d030
---[ end trace 53ca152639ff2a59 ]---

[Sebastian Andrzej Siewior]

On 12/01/2013 11:25 PM, Pavel Vasilyev wrote:
> ------------[ cut here ]------------
> WARNING: CPU: 1 PID: 10 at kernel/time/tick-sched.c:191 0xffffffff8107bac6()
> NO_HZ FULL will not work with unstable sched clock

> Call Trace:
> <IRQ> [<ffffffff81501a58>] 0xffffffff81501a58
> [<ffffffff8102f992>] 0xffffffff8102f992

Okay. Now we have a backstrace. Better. Now there is an option named
CONFIG_DEBUG_INFO which resolves a number like 0xffffffff81501a58 to
the function name. Without it enabled, the backtrace is of no use to me.

However, in this case you triggered the warning in tick-sched.c. The
good news is that FULL-NO-HZ mode is not available because your TSC is
unstable and this is all the backtrace is about so it is harmless. You
should see it even without -RT enabled. The bad news is that I don't
think that this has anything to do with your SATA problem.

Sebastian