diff options
Diffstat (limited to 'debian/patches-rt/0005-locking-rtmutex-Use-rt_mutex-specific-scheduler-help.patch')
| -rw-r--r-- | debian/patches-rt/0005-locking-rtmutex-Use-rt_mutex-specific-scheduler-help.patch | 177 |
1 files changed, 0 insertions, 177 deletions
diff --git a/debian/patches-rt/0005-locking-rtmutex-Use-rt_mutex-specific-scheduler-help.patch b/debian/patches-rt/0005-locking-rtmutex-Use-rt_mutex-specific-scheduler-help.patch deleted file mode 100644 index d84497e5f..000000000 --- a/debian/patches-rt/0005-locking-rtmutex-Use-rt_mutex-specific-scheduler-help.patch +++ /dev/null @@ -1,177 +0,0 @@ -From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> -Date: Fri, 8 Sep 2023 18:22:52 +0200 -Subject: [PATCH 5/7] locking/rtmutex: Use rt_mutex specific scheduler helpers -Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.tar.xz - -Have rt_mutex use the rt_mutex specific scheduler helpers to avoid -recursion vs rtlock on the PI state. - -[[ peterz: adapted to new names ]] - -Reported-by: Crystal Wood <swood@redhat.com> -Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> -Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> -Link: https://lkml.kernel.org/r/20230908162254.999499-6-bigeasy@linutronix.de ---- - kernel/futex/pi.c | 11 +++++++++++ - kernel/locking/rtmutex.c | 14 ++++++++++++-- - kernel/locking/rwbase_rt.c | 6 ++++++ - kernel/locking/rwsem.c | 8 +++++++- - kernel/locking/spinlock_rt.c | 4 ++++ - 5 files changed, 40 insertions(+), 3 deletions(-) - ---- a/kernel/futex/pi.c -+++ b/kernel/futex/pi.c -@@ -1,6 +1,7 @@ - // SPDX-License-Identifier: GPL-2.0-or-later - - #include <linux/slab.h> -+#include <linux/sched/rt.h> - #include <linux/sched/task.h> - - #include "futex.h" -@@ -1002,6 +1003,12 @@ int futex_lock_pi(u32 __user *uaddr, uns - goto no_block; - } - -+ /* -+ * Must be done before we enqueue the waiter, here is unfortunately -+ * under the hb lock, but that *should* work because it does nothing. -+ */ -+ rt_mutex_pre_schedule(); -+ - rt_mutex_init_waiter(&rt_waiter); - - /* -@@ -1052,6 +1059,10 @@ int futex_lock_pi(u32 __user *uaddr, uns - if (ret && !rt_mutex_cleanup_proxy_lock(&q.pi_state->pi_mutex, &rt_waiter)) - ret = 0; - -+ /* -+ * Waiter is unqueued. -+ */ -+ rt_mutex_post_schedule(); - no_block: - /* - * Fixup the pi_state owner and possibly acquire the lock if we ---- a/kernel/locking/rtmutex.c -+++ b/kernel/locking/rtmutex.c -@@ -1632,7 +1632,7 @@ static int __sched rt_mutex_slowlock_blo - raw_spin_unlock_irq(&lock->wait_lock); - - if (!owner || !rtmutex_spin_on_owner(lock, waiter, owner)) -- schedule(); -+ rt_mutex_schedule(); - - raw_spin_lock_irq(&lock->wait_lock); - set_current_state(state); -@@ -1661,7 +1661,7 @@ static void __sched rt_mutex_handle_dead - WARN(1, "rtmutex deadlock detected\n"); - while (1) { - set_current_state(TASK_INTERRUPTIBLE); -- schedule(); -+ rt_mutex_schedule(); - } - } - -@@ -1757,6 +1757,15 @@ static int __sched rt_mutex_slowlock(str - int ret; - - /* -+ * Do all pre-schedule work here, before we queue a waiter and invoke -+ * PI -- any such work that trips on rtlock (PREEMPT_RT spinlock) would -+ * otherwise recurse back into task_blocks_on_rt_mutex() through -+ * rtlock_slowlock() and will then enqueue a second waiter for this -+ * same task and things get really confusing real fast. -+ */ -+ rt_mutex_pre_schedule(); -+ -+ /* - * Technically we could use raw_spin_[un]lock_irq() here, but this can - * be called in early boot if the cmpxchg() fast path is disabled - * (debug, no architecture support). In this case we will acquire the -@@ -1767,6 +1776,7 @@ static int __sched rt_mutex_slowlock(str - raw_spin_lock_irqsave(&lock->wait_lock, flags); - ret = __rt_mutex_slowlock_locked(lock, ww_ctx, state); - raw_spin_unlock_irqrestore(&lock->wait_lock, flags); -+ rt_mutex_post_schedule(); - - return ret; - } ---- a/kernel/locking/rwbase_rt.c -+++ b/kernel/locking/rwbase_rt.c -@@ -71,6 +71,7 @@ static int __sched __rwbase_read_lock(st - struct rt_mutex_base *rtm = &rwb->rtmutex; - int ret; - -+ rwbase_pre_schedule(); - raw_spin_lock_irq(&rtm->wait_lock); - - /* -@@ -125,6 +126,7 @@ static int __sched __rwbase_read_lock(st - rwbase_rtmutex_unlock(rtm); - - trace_contention_end(rwb, ret); -+ rwbase_post_schedule(); - return ret; - } - -@@ -237,6 +239,8 @@ static int __sched rwbase_write_lock(str - /* Force readers into slow path */ - atomic_sub(READER_BIAS, &rwb->readers); - -+ rwbase_pre_schedule(); -+ - raw_spin_lock_irqsave(&rtm->wait_lock, flags); - if (__rwbase_write_trylock(rwb)) - goto out_unlock; -@@ -248,6 +252,7 @@ static int __sched rwbase_write_lock(str - if (rwbase_signal_pending_state(state, current)) { - rwbase_restore_current_state(); - __rwbase_write_unlock(rwb, 0, flags); -+ rwbase_post_schedule(); - trace_contention_end(rwb, -EINTR); - return -EINTR; - } -@@ -266,6 +271,7 @@ static int __sched rwbase_write_lock(str - - out_unlock: - raw_spin_unlock_irqrestore(&rtm->wait_lock, flags); -+ rwbase_post_schedule(); - return 0; - } - ---- a/kernel/locking/rwsem.c -+++ b/kernel/locking/rwsem.c -@@ -1427,8 +1427,14 @@ static inline void __downgrade_write(str - #define rwbase_signal_pending_state(state, current) \ - signal_pending_state(state, current) - -+#define rwbase_pre_schedule() \ -+ rt_mutex_pre_schedule() -+ - #define rwbase_schedule() \ -- schedule() -+ rt_mutex_schedule() -+ -+#define rwbase_post_schedule() \ -+ rt_mutex_post_schedule() - - #include "rwbase_rt.c" - ---- a/kernel/locking/spinlock_rt.c -+++ b/kernel/locking/spinlock_rt.c -@@ -184,9 +184,13 @@ static __always_inline int rwbase_rtmut - - #define rwbase_signal_pending_state(state, current) (0) - -+#define rwbase_pre_schedule() -+ - #define rwbase_schedule() \ - schedule_rtlock() - -+#define rwbase_post_schedule() -+ - #include "rwbase_rt.c" - /* - * The common functions which get wrapped into the rwlock API. |