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

[Greg KH]

On Wed, Aug 08, 2018 at 05:07:08PM -0700, Matthew Wilcox wrote:
> 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.

What?  Why would they do that?  Who cares about tear-down speeds?  Start
up speeds I can kind of understand...