On Sat 04-09-21 18:41:00, yong w wrote:
[..]

quoted

It is not in conflict but runtime overhead reduction without more burden
on the configurability is usually a preferred approach.

I agree with you.I had an idea that we use global variables to identify whether
there is event registration,however, global variables need to be
protected with locks.

Have a look at static keys which are usual tool to provide effectivelly
zero overhead disabled branch.
-- 
Michal Hocko
SUSE Labs