Re: [PATCH RFC 01/10] rcu: Make CONFIG_SRCU unconditionally enabled

[Matthew Wilcox]

On Thu, Aug 09, 2018 at 07:31:25AM +1000, Dave Chinner wrote:
> IMO, we've had enough recent bugs to deal with from shrinkers being
> called before the filesystem is set up and from trying to handle
> allocation errors during setup. Do we really want to make shrinker
> shutdown just as prone to mismanagement and subtle, hard to hit
> bugs? I don't think we do - unmount is simply not a critical
> performance path.

It's never been performance critical for me, but I'm not so sure that
there aren't container workloads which unmount filesystems multiple
times per second.