On Mon, Feb 12, 2007 at 12:15:24AM -0800, menage at google.com wrote: > +/* > + * Call css_get() to hold a reference on the container; following a > + * return of 0, this container subsystem state object is guaranteed > + * not to be destroyed until css_put() is called on it. A non-zero > + * return code indicates that a reference could not be taken. > + * > + */ > + Why can't we reuse container->count (or container_group->ref) to refcount the per-subsystem object attached to a container? I think that is how it is done for cpusets? That would make css_get/put unnecessary? > +static inline int css_get(struct container_subsys_state *css) > +{ > + int retval = 0; > + unsigned long flags; > + /* Synchronize with container_rmdir() */ > + spin_lock_irqsave(&css->refcnt_lock, flags); > + if (atomic_read(&css->refcnt) >= 0) { > + /* Container is still alive */ > + atomic_inc(&css->refcnt); > + } else { > + /* Container removal is in progress */ > + retval = -EINVAL; > + } > + spin_unlock_irqrestore(&css->refcnt_lock, flags); > + return retval; > +} -- Regards, vatsa