On Oct 10, 3:27pm, campbell+netbsd-tech-k...@mumble.net (Taylor R Campbell) wrote: -- Subject: Re: Anomalies while handling p_nstopchild count
| proc_lock may be held by another thread even if the caller is | guaranteed not to hold it. The other thread may furthermore be | waiting on p->p_lock, in which case acquiring p->p_lock here would | lead to deadlock -- but mutex_tryenter would simply fail. | | The optimization is to optimistically assume nobody else is holding | proc_lock and do mutex_tryenter. Otherwise, we back out and acquire | both locks in the correct order. Thanks, now I get it! christos
