[openib-general] Re: [PATCH] cm refcount race fix

[Sean Hefty]

Michael S. Tsirkin wrote:
>  static inline void cm_deref_id(struct cm_id_private *cm_id_priv)
>  {
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&cm_id_priv->lock, flags);
>  	if (atomic_dec_and_test(&cm_id_priv->refcount))
>  		wake_up(&cm_id_priv->wait);
> +	spin_unlock_irqrestore(&cm_id_priv->lock, flags);
>  }

Could we use atomic_dec_and_lock() instead?  This would keep refcount atomic, 
but use a spinlock to synchronize with destruction.

- Sean