On Fri, Sep 11, 2015 at 02:37:37PM -0400, Waiman Long wrote:
> +#define queued_spin_trylock(l) pv_queued_spin_trylock_unfair(l)
> +static inline bool pv_queued_spin_trylock_unfair(struct qspinlock *lock)
> +{
> + struct __qspinlock *l = (void *)lock;
> +
> + if (READ_ONCE(l->locked))
> + return 0;
> + /*
> + * Wait a bit here to ensure that an actively spinning vCPU has a fair
> + * chance of getting the lock.
> + */
> + cpu_relax();
> +
> + return cmpxchg(&l->locked, 0, _Q_LOCKED_VAL) == 0;
> +}
> +static inline int pvstat_trylock_unfair(struct qspinlock *lock)
> +{
> + int ret = pv_queued_spin_trylock_unfair(lock);
> +
> + if (ret)
> + pvstat_inc(pvstat_utrylock);
> + return ret;
> +}
> +#undef queued_spin_trylock
> +#define queued_spin_trylock(l) pvstat_trylock_unfair(l)
These aren't actually ever used...
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