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| author | Thomas Gleixner <tglx@linutronix.de> | 2021-09-23 18:54:35 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2021-10-01 13:57:49 +0200 |
| commit | 874f670e6088d3bff3972ecd44c1cb00610f9183 (patch) | |
| tree | ec4a3568328504f71947fdb4aa27133ed6e4a675 /kernel/locking | |
| parent | locking/ww-mutex: Fix uninitialized use of ret in test_aa() (diff) | |
| download | linux-874f670e6088d3bff3972ecd44c1cb00610f9183.tar.xz linux-874f670e6088d3bff3972ecd44c1cb00610f9183.zip | |
sched: Clean up the might_sleep() underscore zoo
__might_sleep() vs. ___might_sleep() is hard to distinguish. Aside of that
the three underscore variant is exposed to provide a checkpoint for
rescheduling points which are distinct from blocking points.
They are semantically a preemption point which means that scheduling is
state preserving. A real blocking operation, e.g. mutex_lock(), wait*(),
which cannot preserve a task state which is not equal to RUNNING.
While technically blocking on a "sleeping" spinlock in RT enabled kernels
falls into the voluntary scheduling category because it has to wait until
the contended spin/rw lock becomes available, the RT lock substitution code
can semantically be mapped to a voluntary preemption because the RT lock
substitution code and the scheduler are providing mechanisms to preserve
the task state and to take regular non-lock related wakeups into account.
Rename ___might_sleep() to __might_resched() to make the distinction of
these functions clear.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210923165357.928693482@linutronix.de
Diffstat (limited to 'kernel/locking')
| -rw-r--r-- | kernel/locking/spinlock_rt.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/kernel/locking/spinlock_rt.c b/kernel/locking/spinlock_rt.c index d2912e44d61f..c5289240cfb4 100644 --- a/kernel/locking/spinlock_rt.c +++ b/kernel/locking/spinlock_rt.c @@ -32,7 +32,7 @@ static __always_inline void rtlock_lock(struct rt_mutex_base *rtm) static __always_inline void __rt_spin_lock(spinlock_t *lock) { - ___might_sleep(__FILE__, __LINE__, 0); + __might_resched(__FILE__, __LINE__, 0); rtlock_lock(&lock->lock); rcu_read_lock(); migrate_disable(); @@ -210,7 +210,7 @@ EXPORT_SYMBOL(rt_write_trylock); void __sched rt_read_lock(rwlock_t *rwlock) { - ___might_sleep(__FILE__, __LINE__, 0); + __might_resched(__FILE__, __LINE__, 0); rwlock_acquire_read(&rwlock->dep_map, 0, 0, _RET_IP_); rwbase_read_lock(&rwlock->rwbase, TASK_RTLOCK_WAIT); rcu_read_lock(); @@ -220,7 +220,7 @@ EXPORT_SYMBOL(rt_read_lock); void __sched rt_write_lock(rwlock_t *rwlock) { - ___might_sleep(__FILE__, __LINE__, 0); + __might_resched(__FILE__, __LINE__, 0); rwlock_acquire(&rwlock->dep_map, 0, 0, _RET_IP_); rwbase_write_lock(&rwlock->rwbase, TASK_RTLOCK_WAIT); rcu_read_lock(); |