diff options
| author | Ben Gardon <bgardon@google.com> | 2021-02-02 21:57:14 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-02-04 13:27:43 +0300 |
| commit | f3d4b4b1dc1c5fb9ea17cac14133463bfe72f170 (patch) | |
| tree | e5c72ff9e9518c7817fca537fb67f09cf6fef844 | |
| parent | a09a689a534183c48f200bc2de1ae61ae9c462ad (diff) | |
| download | linux-f3d4b4b1dc1c5fb9ea17cac14133463bfe72f170.tar.xz | |
sched: Add cond_resched_rwlock
Safely rescheduling while holding a spin lock is essential for keeping
long running kernel operations running smoothly. Add the facility to
cond_resched rwlocks.
CC: Ingo Molnar <mingo@redhat.com>
CC: Will Deacon <will@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Waiman Long <longman@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20210202185734.1680553-9-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | include/linux/sched.h | 12 | ||||
| -rw-r--r-- | kernel/sched/core.c | 40 |
2 files changed, 52 insertions, 0 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 5d1378e5a040..3052d16da3cf 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1883,12 +1883,24 @@ static inline int _cond_resched(void) { return 0; } }) extern int __cond_resched_lock(spinlock_t *lock); +extern int __cond_resched_rwlock_read(rwlock_t *lock); +extern int __cond_resched_rwlock_write(rwlock_t *lock); #define cond_resched_lock(lock) ({ \ ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\ __cond_resched_lock(lock); \ }) +#define cond_resched_rwlock_read(lock) ({ \ + __might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET); \ + __cond_resched_rwlock_read(lock); \ +}) + +#define cond_resched_rwlock_write(lock) ({ \ + __might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET); \ + __cond_resched_rwlock_write(lock); \ +}) + static inline void cond_resched_rcu(void) { #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 15d2562118d1..ade357642279 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6695,6 +6695,46 @@ int __cond_resched_lock(spinlock_t *lock) } EXPORT_SYMBOL(__cond_resched_lock); +int __cond_resched_rwlock_read(rwlock_t *lock) +{ + int resched = should_resched(PREEMPT_LOCK_OFFSET); + int ret = 0; + + lockdep_assert_held_read(lock); + + if (rwlock_needbreak(lock) || resched) { + read_unlock(lock); + if (resched) + preempt_schedule_common(); + else + cpu_relax(); + ret = 1; + read_lock(lock); + } + return ret; +} +EXPORT_SYMBOL(__cond_resched_rwlock_read); + +int __cond_resched_rwlock_write(rwlock_t *lock) +{ + int resched = should_resched(PREEMPT_LOCK_OFFSET); + int ret = 0; + + lockdep_assert_held_write(lock); + + if (rwlock_needbreak(lock) || resched) { + write_unlock(lock); + if (resched) + preempt_schedule_common(); + else + cpu_relax(); + ret = 1; + write_lock(lock); + } + return ret; +} +EXPORT_SYMBOL(__cond_resched_rwlock_write); + /** * yield - yield the current processor to other threads. * |