Messages in this thread | | | Date | Tue, 5 Jul 2022 16:15:18 -0400 | Subject | Re: [PATCH 11/13] locking/qspinlock: Use queued_spin_trylock in pv_hybrid_queued_unfair_trylock | From | Waiman Long <> |
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On 7/4/22 10:38, Nicholas Piggin wrote: > Rather than open-code it as necessitated by the old function-renaming > code generation that rendered queued_spin_trylock unavailable to use > here. > > Signed-off-by: Nicholas Piggin <npiggin@gmail.com> > --- > kernel/locking/qspinlock.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c > index cef0ca7d94e1..9db168753124 100644 > --- a/kernel/locking/qspinlock.c > +++ b/kernel/locking/qspinlock.c > @@ -357,7 +357,7 @@ static inline bool pv_hybrid_queued_unfair_trylock(struct qspinlock *lock) > int val = atomic_read(&lock->val); > > if (!(val & _Q_LOCKED_PENDING_MASK) && > - (cmpxchg_acquire(&lock->locked, 0, _Q_LOCKED_VAL) == 0)) { > + queued_spin_trylock(lock)) { > lockevent_inc(pv_lock_stealing); > return true; > }
I am not sure if the compiler will eliminate the duplicated atomic_read() in queued_spin_trylock(). So unless it can generate the same code, I would prefer to leave this alone.
Cheers, Longman
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