Re: [PATCH V8 5/8] percpu-refcount: introduce __percpu_ref_tryget_live
From: Ming Lei
Date: Tue Oct 03 2017 - 15:24:34 EST
On Tue, Oct 03, 2017 at 06:40:24PM +0000, Bart Van Assche wrote:
> On Tue, 2017-10-03 at 22:04 +0800, Ming Lei wrote:
> > Block layer need to call this function after holding
> > rcu lock in a real hot path, so introduce this helper.
> Since it is allowed to nest rcu_read_lock_sched() calls I don't think
> that this patch is necessary.
Yeah, I know that, with this patch, we can avoid the nest RCU lock.
As I mentioned, it is a real hot path, so maybe better to not
introduce the extra RCU read lock/unlock.
If you guys doesn't care the little cost, I can remove that.