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-rw-r--r--debian/patches-rt/rtmutex-annotate-sleeping-lock-context.patch294
1 files changed, 0 insertions, 294 deletions
diff --git a/debian/patches-rt/rtmutex-annotate-sleeping-lock-context.patch b/debian/patches-rt/rtmutex-annotate-sleeping-lock-context.patch
deleted file mode 100644
index 765d7f10b..000000000
--- a/debian/patches-rt/rtmutex-annotate-sleeping-lock-context.patch
+++ /dev/null
@@ -1,294 +0,0 @@
-From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
-Date: Thu, 21 Sep 2017 14:25:13 +0200
-Subject: [PATCH] rtmutex: annotate sleeping lock context
-Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.2/older/patches-5.2.17-rt9.tar.xz
-
-The RCU code complains on schedule() within a rcu_readlock() section.
-The valid scenario on -RT is if a sleeping is held. In order to suppress
-the warning the mirgrate_disable counter was used to identify the
-invocation of schedule() due to lock contention.
-
-Grygorii Strashko report that during CPU hotplug we might see the
-warning via
- rt_spin_lock() -> migrate_disable() -> pin_current_cpu() -> __read_rt_lock()
-
-because the counter is not yet set.
-It is also possible to trigger the warning from cpu_chill()
-(seen on a kblockd_mod_delayed_work_on() caller).
-
-To address this RCU warning I annotate the sleeping lock context. The
-counter is incremented before migrate_disable() so the warning Grygorii
-should not trigger anymore. Additionally I use that counter in
-cpu_chill() to avoid the RCU warning from there.
-
-Reported-by: Grygorii Strashko <grygorii.strashko@ti.com>
-Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
----
- include/linux/preempt.h | 9 +++++++++
- include/linux/sched.h | 26 ++++++++++++++++++++++++++
- kernel/locking/rtmutex.c | 12 ++++++++++--
- kernel/locking/rwlock-rt.c | 18 ++++++++++++++----
- kernel/rcu/tree_plugin.h | 6 +++++-
- kernel/sched/core.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
- 6 files changed, 109 insertions(+), 7 deletions(-)
-
---- a/include/linux/preempt.h
-+++ b/include/linux/preempt.h
-@@ -208,6 +208,15 @@ extern void migrate_enable(void);
-
- int __migrate_disabled(struct task_struct *p);
-
-+#elif !defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT_BASE)
-+
-+extern void migrate_disable(void);
-+extern void migrate_enable(void);
-+static inline int __migrate_disabled(struct task_struct *p)
-+{
-+ return 0;
-+}
-+
- #else
- #define migrate_disable() barrier()
- #define migrate_enable() barrier()
---- a/include/linux/sched.h
-+++ b/include/linux/sched.h
-@@ -664,6 +664,15 @@ struct task_struct {
- # ifdef CONFIG_SCHED_DEBUG
- int migrate_disable_atomic;
- # endif
-+
-+#elif !defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT_BASE)
-+ int migrate_disable;
-+# ifdef CONFIG_SCHED_DEBUG
-+ int migrate_disable_atomic;
-+# endif
-+#endif
-+#ifdef CONFIG_PREEMPT_RT_FULL
-+ int sleeping_lock;
- #endif
-
- #ifdef CONFIG_PREEMPT_RCU
-@@ -1824,6 +1833,23 @@ static __always_inline bool need_resched
- return unlikely(tif_need_resched());
- }
-
-+#ifdef CONFIG_PREEMPT_RT_FULL
-+static inline void sleeping_lock_inc(void)
-+{
-+ current->sleeping_lock++;
-+}
-+
-+static inline void sleeping_lock_dec(void)
-+{
-+ current->sleeping_lock--;
-+}
-+
-+#else
-+
-+static inline void sleeping_lock_inc(void) { }
-+static inline void sleeping_lock_dec(void) { }
-+#endif
-+
- /*
- * Wrappers for p->thread_info->cpu access. No-op on UP.
- */
---- a/kernel/locking/rtmutex.c
-+++ b/kernel/locking/rtmutex.c
-@@ -1135,6 +1135,7 @@ void __sched rt_spin_lock_slowunlock(str
-
- void __lockfunc rt_spin_lock(spinlock_t *lock)
- {
-+ sleeping_lock_inc();
- migrate_disable();
- spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
- rt_spin_lock_fastlock(&lock->lock, rt_spin_lock_slowlock);
-@@ -1149,6 +1150,7 @@ void __lockfunc __rt_spin_lock(struct rt
- #ifdef CONFIG_DEBUG_LOCK_ALLOC
- void __lockfunc rt_spin_lock_nested(spinlock_t *lock, int subclass)
- {
-+ sleeping_lock_inc();
- migrate_disable();
- spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
- rt_spin_lock_fastlock(&lock->lock, rt_spin_lock_slowlock);
-@@ -1162,6 +1164,7 @@ void __lockfunc rt_spin_unlock(spinlock_
- spin_release(&lock->dep_map, 1, _RET_IP_);
- rt_spin_lock_fastunlock(&lock->lock, rt_spin_lock_slowunlock);
- migrate_enable();
-+ sleeping_lock_dec();
- }
- EXPORT_SYMBOL(rt_spin_unlock);
-
-@@ -1187,12 +1190,15 @@ int __lockfunc rt_spin_trylock(spinlock_
- {
- int ret;
-
-+ sleeping_lock_inc();
- migrate_disable();
- ret = __rt_mutex_trylock(&lock->lock);
-- if (ret)
-+ if (ret) {
- spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
-- else
-+ } else {
- migrate_enable();
-+ sleeping_lock_dec();
-+ }
- return ret;
- }
- EXPORT_SYMBOL(rt_spin_trylock);
-@@ -1204,6 +1210,7 @@ int __lockfunc rt_spin_trylock_bh(spinlo
- local_bh_disable();
- ret = __rt_mutex_trylock(&lock->lock);
- if (ret) {
-+ sleeping_lock_inc();
- migrate_disable();
- spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
- } else
-@@ -1219,6 +1226,7 @@ int __lockfunc rt_spin_trylock_irqsave(s
- *flags = 0;
- ret = __rt_mutex_trylock(&lock->lock);
- if (ret) {
-+ sleeping_lock_inc();
- migrate_disable();
- spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
- }
---- a/kernel/locking/rwlock-rt.c
-+++ b/kernel/locking/rwlock-rt.c
-@@ -305,12 +305,15 @@ int __lockfunc rt_read_trylock(rwlock_t
- {
- int ret;
-
-+ sleeping_lock_inc();
- migrate_disable();
- ret = do_read_rt_trylock(rwlock);
-- if (ret)
-+ if (ret) {
- rwlock_acquire_read(&rwlock->dep_map, 0, 1, _RET_IP_);
-- else
-+ } else {
- migrate_enable();
-+ sleeping_lock_dec();
-+ }
- return ret;
- }
- EXPORT_SYMBOL(rt_read_trylock);
-@@ -319,18 +322,22 @@ int __lockfunc rt_write_trylock(rwlock_t
- {
- int ret;
-
-+ sleeping_lock_inc();
- migrate_disable();
- ret = do_write_rt_trylock(rwlock);
-- if (ret)
-+ if (ret) {
- rwlock_acquire(&rwlock->dep_map, 0, 1, _RET_IP_);
-- else
-+ } else {
- migrate_enable();
-+ sleeping_lock_dec();
-+ }
- return ret;
- }
- EXPORT_SYMBOL(rt_write_trylock);
-
- void __lockfunc rt_read_lock(rwlock_t *rwlock)
- {
-+ sleeping_lock_inc();
- migrate_disable();
- rwlock_acquire_read(&rwlock->dep_map, 0, 0, _RET_IP_);
- do_read_rt_lock(rwlock);
-@@ -339,6 +346,7 @@ EXPORT_SYMBOL(rt_read_lock);
-
- void __lockfunc rt_write_lock(rwlock_t *rwlock)
- {
-+ sleeping_lock_inc();
- migrate_disable();
- rwlock_acquire(&rwlock->dep_map, 0, 0, _RET_IP_);
- do_write_rt_lock(rwlock);
-@@ -350,6 +358,7 @@ void __lockfunc rt_read_unlock(rwlock_t
- rwlock_release(&rwlock->dep_map, 1, _RET_IP_);
- do_read_rt_unlock(rwlock);
- migrate_enable();
-+ sleeping_lock_dec();
- }
- EXPORT_SYMBOL(rt_read_unlock);
-
-@@ -358,6 +367,7 @@ void __lockfunc rt_write_unlock(rwlock_t
- rwlock_release(&rwlock->dep_map, 1, _RET_IP_);
- do_write_rt_unlock(rwlock);
- migrate_enable();
-+ sleeping_lock_dec();
- }
- EXPORT_SYMBOL(rt_write_unlock);
-
---- a/kernel/rcu/tree_plugin.h
-+++ b/kernel/rcu/tree_plugin.h
-@@ -307,11 +307,15 @@ void rcu_note_context_switch(bool preemp
- struct task_struct *t = current;
- struct rcu_data *rdp = this_cpu_ptr(&rcu_data);
- struct rcu_node *rnp;
-+ int sleeping_l = 0;
-
- barrier(); /* Avoid RCU read-side critical sections leaking down. */
- trace_rcu_utilization(TPS("Start context switch"));
- lockdep_assert_irqs_disabled();
-- WARN_ON_ONCE(!preempt && t->rcu_read_lock_nesting > 0);
-+#if defined(CONFIG_PREEMPT_RT_FULL)
-+ sleeping_l = t->sleeping_lock;
-+#endif
-+ WARN_ON_ONCE(!preempt && t->rcu_read_lock_nesting > 0 && !sleeping_l);
- if (t->rcu_read_lock_nesting > 0 &&
- !t->rcu_read_unlock_special.b.blocked) {
-
---- a/kernel/sched/core.c
-+++ b/kernel/sched/core.c
-@@ -7326,4 +7326,49 @@ void migrate_enable(void)
- preempt_enable();
- }
- EXPORT_SYMBOL(migrate_enable);
-+
-+#elif !defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT_BASE)
-+void migrate_disable(void)
-+{
-+ struct task_struct *p = current;
-+
-+ if (in_atomic() || irqs_disabled()) {
-+#ifdef CONFIG_SCHED_DEBUG
-+ p->migrate_disable_atomic++;
-+#endif
-+ return;
-+ }
-+#ifdef CONFIG_SCHED_DEBUG
-+ if (unlikely(p->migrate_disable_atomic)) {
-+ tracing_off();
-+ WARN_ON_ONCE(1);
-+ }
-+#endif
-+
-+ p->migrate_disable++;
-+}
-+EXPORT_SYMBOL(migrate_disable);
-+
-+void migrate_enable(void)
-+{
-+ struct task_struct *p = current;
-+
-+ if (in_atomic() || irqs_disabled()) {
-+#ifdef CONFIG_SCHED_DEBUG
-+ p->migrate_disable_atomic--;
-+#endif
-+ return;
-+ }
-+
-+#ifdef CONFIG_SCHED_DEBUG
-+ if (unlikely(p->migrate_disable_atomic)) {
-+ tracing_off();
-+ WARN_ON_ONCE(1);
-+ }
-+#endif
-+
-+ WARN_ON_ONCE(p->migrate_disable <= 0);
-+ p->migrate_disable--;
-+}
-+EXPORT_SYMBOL(migrate_enable);
- #endif
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