diff options
| author |   Kefeng Wang <wangkefeng.wang@huawei.com> | 2021-12-03 15:59:34 +0800 |
|---|---|---|
| committer |   Peter Zijlstra <peterz@infradead.org> | 2021-12-04 10:56:25 +0100 |
| commit | c0bed69daf4b67809b58cc7cd81a8fa4f45bc161 (patch) | |
| tree | 2e5eac02c318c1145dace9791e1e53b74ca0dc49 | |
| parent | lockdep/selftests: Adapt ww-tests for PREEMPT_RT (diff) | |
| download | linux-dev-c0bed69daf4b67809b58cc7cd81a8fa4f45bc161.tar.xz linux-dev-c0bed69daf4b67809b58cc7cd81a8fa4f45bc161.zip | |
locking: Make owner_on_cpu() into <linux/sched.h>
Move the owner_on_cpu() from kernel/locking/rwsem.c into
include/linux/sched.h with under CONFIG_SMP, then use it
in the mutex/rwsem/rtmutex to simplify the code.
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20211203075935.136808-2-wangkefeng.wang@huawei.com
| -rw-r--r-- | include/linux/sched.h | 9 | ||||
| -rw-r--r-- | kernel/locking/mutex.c | 11 | ||||
| -rw-r--r-- | kernel/locking/rtmutex.c | 5 | ||||
| -rw-r--r-- | kernel/locking/rwsem.c | 9 |
4 files changed, 13 insertions, 21 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 78c351e35fec..ff609d9c2f21 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2171,6 +2171,15 @@ extern long sched_getaffinity(pid_t pid, struct cpumask *mask); #endif #ifdef CONFIG_SMP +static inline bool owner_on_cpu(struct task_struct *owner) +{ + /* + * As lock holder preemption issue, we both skip spinning if + * task is not on cpu or its cpu is preempted + */ + return owner->on_cpu && !vcpu_is_preempted(task_cpu(owner)); +} + /* Returns effective CPU energy utilization, as seen by the scheduler */ unsigned long sched_cpu_util(int cpu, unsigned long max); #endif /* CONFIG_SMP */ diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c index db1913611192..5e3585950ec8 100644 --- a/kernel/locking/mutex.c +++ b/kernel/locking/mutex.c @@ -367,8 +367,7 @@ bool mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner, /* * Use vcpu_is_preempted to detect lock holder preemption issue. */ - if (!owner->on_cpu || need_resched() || - vcpu_is_preempted(task_cpu(owner))) { + if (!owner_on_cpu(owner) || need_resched()) { ret = false; break; } @@ -403,14 +402,8 @@ static inline int mutex_can_spin_on_owner(struct mutex *lock) * structure won't go away during the spinning period. */ owner = __mutex_owner(lock); - - /* - * As lock holder preemption issue, we both skip spinning if task is not - * on cpu or its cpu is preempted - */ - if (owner) - retval = owner->on_cpu && !vcpu_is_preempted(task_cpu(owner)); + retval = owner_on_cpu(owner); /* * If lock->owner is not set, the mutex has been released. Return true diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c index f89620852774..0c1f2e3f019a 100644 --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -1382,9 +1382,8 @@ 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; } diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index c51387a43265..b92d0a830568 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -613,15 +613,6 @@ static inline bool rwsem_try_write_lock_unqueued(struct rw_semaphore *sem) return false; } -static inline bool owner_on_cpu(struct task_struct *owner) -{ - /* - * As lock holder preemption issue, we both skip spinning if - * task is not on cpu or its cpu is preempted - */ - return owner->on_cpu && !vcpu_is_preempted(task_cpu(owner)); -} - static inline bool rwsem_can_spin_on_owner(struct rw_semaphore *sem) { struct task_struct *owner; |