[dm-devel] [PATCH] backing-dev: use synchronize_rcu_expedited instead of synchronize_rcu

[Peter Zijlstra]

On Thu, 2012-02-02 at 15:43 -0500, Mikulas Patocka wrote:
> Do you have some measurable use case where the user is removing block 
> devices so heavily that this causes a problem? 

Even one can be a problem, we're having people spend lots of time and
effort to reduce machine wide jitter and interference. Adding it with
such disregard isn't cool.

There's no reason a management cpu adding or removing block devices
should perturb the high-freq trading or industrial laser control running
on the other side of the machine.