diff options
Diffstat (limited to 'debian/patches-rt/0002-locking-rtmutex-Avoid-unconditional-slowpath-for-DEB.patch')
-rw-r--r-- | debian/patches-rt/0002-locking-rtmutex-Avoid-unconditional-slowpath-for-DEB.patch | 79 |
1 files changed, 0 insertions, 79 deletions
diff --git a/debian/patches-rt/0002-locking-rtmutex-Avoid-unconditional-slowpath-for-DEB.patch b/debian/patches-rt/0002-locking-rtmutex-Avoid-unconditional-slowpath-for-DEB.patch deleted file mode 100644 index 561d5891b1..0000000000 --- a/debian/patches-rt/0002-locking-rtmutex-Avoid-unconditional-slowpath-for-DEB.patch +++ /dev/null @@ -1,79 +0,0 @@ -From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> -Date: Fri, 8 Sep 2023 18:22:49 +0200 -Subject: [PATCH 2/7] locking/rtmutex: Avoid unconditional slowpath for - DEBUG_RT_MUTEXES -Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.tar.xz - -With DEBUG_RT_MUTEXES enabled the fast-path rt_mutex_cmpxchg_acquire() -always fails and all lock operations take the slow path. - -Provide a new helper inline rt_mutex_try_acquire() which maps to -rt_mutex_cmpxchg_acquire() in the non-debug case. For the debug case -it invokes rt_mutex_slowtrylock() which can acquire a non-contended -rtmutex under full debug coverage. - -Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> -Signed-off-by: Thomas Gleixner <tglx@linutronix.de> -Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> -Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> -Link: https://lkml.kernel.org/r/20230908162254.999499-3-bigeasy@linutronix.de ---- - kernel/locking/rtmutex.c | 21 ++++++++++++++++++++- - kernel/locking/ww_rt_mutex.c | 2 +- - 2 files changed, 21 insertions(+), 2 deletions(-) - ---- a/kernel/locking/rtmutex.c -+++ b/kernel/locking/rtmutex.c -@@ -218,6 +218,11 @@ static __always_inline bool rt_mutex_cmp - return try_cmpxchg_acquire(&lock->owner, &old, new); - } - -+static __always_inline bool rt_mutex_try_acquire(struct rt_mutex_base *lock) -+{ -+ return rt_mutex_cmpxchg_acquire(lock, NULL, current); -+} -+ - static __always_inline bool rt_mutex_cmpxchg_release(struct rt_mutex_base *lock, - struct task_struct *old, - struct task_struct *new) -@@ -297,6 +302,20 @@ static __always_inline bool rt_mutex_cmp - - } - -+static int __sched rt_mutex_slowtrylock(struct rt_mutex_base *lock); -+ -+static __always_inline bool rt_mutex_try_acquire(struct rt_mutex_base *lock) -+{ -+ /* -+ * With debug enabled rt_mutex_cmpxchg trylock() will always fail. -+ * -+ * Avoid unconditionally taking the slow path by using -+ * rt_mutex_slow_trylock() which is covered by the debug code and can -+ * acquire a non-contended rtmutex. -+ */ -+ return rt_mutex_slowtrylock(lock); -+} -+ - static __always_inline bool rt_mutex_cmpxchg_release(struct rt_mutex_base *lock, - struct task_struct *old, - struct task_struct *new) -@@ -1755,7 +1774,7 @@ static int __sched rt_mutex_slowlock(str - static __always_inline int __rt_mutex_lock(struct rt_mutex_base *lock, - unsigned int state) - { -- if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current))) -+ if (likely(rt_mutex_try_acquire(lock))) - return 0; - - return rt_mutex_slowlock(lock, NULL, state); ---- a/kernel/locking/ww_rt_mutex.c -+++ b/kernel/locking/ww_rt_mutex.c -@@ -62,7 +62,7 @@ static int __sched - } - mutex_acquire_nest(&rtm->dep_map, 0, 0, nest_lock, ip); - -- if (likely(rt_mutex_cmpxchg_acquire(&rtm->rtmutex, NULL, current))) { -+ if (likely(rt_mutex_try_acquire(&rtm->rtmutex))) { - if (ww_ctx) - ww_mutex_set_context_fastpath(lock, ww_ctx); - return 0; |