Re: [PATCH] proc: change proc_subdir_lock to a rwlock

Alexey Dobriyan
2015-07-30T10:05:00Z

On Thu, Jul 30, 2015 at 1:21 AM, Eric W. Biederman
<ebiederm@xmission.com> wrote:
> Two quick questions.
>
> - What motivates this work? Are you seeing lots of
> parallel reads on proc?

Well, yes, benchmark looks like very synthetic.
But even gcc opens /proc/meminfo, so might as well
apply the change.

Patch looks like obviously correct to me.

> - Why not rcu? Additions and removal of proc generic
> files is very rare. Conversion to rcu for reads should
> perform better and not take much more work.

If you want proc locking to be understood by ~10 people
on the planet then yes, there is RCU. :-)