diff options
Diffstat (limited to 'kernel/locking/rtmutex.c')
| -rw-r--r-- | kernel/locking/rtmutex.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c index 1f25a4d7de27..7779ee8abc2a 100644 --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -24,6 +24,8 @@ #include <linux/sched/wake_q.h> #include <linux/ww_mutex.h> +#include <trace/events/lock.h> + #include "rtmutex_common.h" #ifndef WW_RT @@ -1103,8 +1105,11 @@ static int __sched task_blocks_on_rt_mutex(struct rt_mutex_base *lock, * the other will detect the deadlock and return -EDEADLOCK, * which is wrong, as the other waiter is not in a deadlock * situation. + * + * Except for ww_mutex, in that case the chain walk must already deal + * with spurious cycles, see the comments at [3] and [6]. */ - if (owner == task) + if (owner == task && !(build_ww_mutex() && ww_ctx)) return -EDEADLK; raw_spin_lock(&task->pi_lock); @@ -1379,9 +1384,8 @@ static bool rtmutex_spin_on_owner(struct rt_mutex_base *lock, * for CONFIG_PREEMPT_RCU=y) * - the VCPU on which owner runs is preempted */ - if (!owner->on_cpu || need_resched() || - !rt_mutex_waiter_is_top_waiter(lock, waiter) || - vcpu_is_preempted(task_cpu(owner))) { + if (!owner_on_cpu(owner) || need_resched() || + !rt_mutex_waiter_is_top_waiter(lock, waiter)) { res = false; break; } @@ -1577,6 +1581,8 @@ static int __sched __rt_mutex_slowlock(struct rt_mutex_base *lock, set_current_state(state); + trace_contention_begin(lock, LCB_F_RT); + ret = task_blocks_on_rt_mutex(lock, waiter, current, ww_ctx, chwalk); if (likely(!ret)) ret = rt_mutex_slowlock_block(lock, ww_ctx, state, NULL, waiter); @@ -1599,6 +1605,9 @@ static int __sched __rt_mutex_slowlock(struct rt_mutex_base *lock, * unconditionally. We might have to fix that up. */ fixup_rt_mutex_waiters(lock); + + trace_contention_end(lock, ret); + return ret; } @@ -1681,6 +1690,8 @@ static void __sched rtlock_slowlock_locked(struct rt_mutex_base *lock) /* Save current state and set state to TASK_RTLOCK_WAIT */ current_save_and_set_rtlock_wait_state(); + trace_contention_begin(lock, LCB_F_RT); + task_blocks_on_rt_mutex(lock, &waiter, current, NULL, RT_MUTEX_MIN_CHAINWALK); for (;;) { @@ -1710,6 +1721,8 @@ static void __sched rtlock_slowlock_locked(struct rt_mutex_base *lock) */ fixup_rt_mutex_waiters(lock); debug_rt_mutex_free_waiter(&waiter); + + trace_contention_end(lock, 0); } static __always_inline void __sched rtlock_slowlock(struct rt_mutex_base *lock) |