On 10/19, Peter Zijlstra wrote:
>
> But using preempt_{disable,enable} and using synchronize_sched() would
> be better (for PREEMPT_RCU) although it wouldn't fix anything
> fundamental.BTW, I agree. I didn't even notice percpu-rwsem.h uses _rcu, not _sched. > Fine goal, although somewhat arch specific. Also note that there's a > relation between atomics and memory barriers, one isn't necessarily > worse than the other, they all require synchronization of sorts. As Paul pointed out, the fast path can avoid mb(). It is only needed when "up_read" detects the writer. Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
