Re: [PATCH 1/2] mm,vmscan: Kill global shrinker lock.

[Christoph Hellwig]

On Mon, Nov 20, 2017 at 10:25:26AM +0100, Michal Hocko wrote:
> On Fri 17-11-17 09:35:21, Christoph Hellwig wrote:
> > On Tue, Nov 14, 2017 at 06:37:42AM +0900, Tetsuo Handa wrote:
> > > Since do_shrink_slab() can reschedule, we cannot protect shrinker_list
> > > using one RCU section. But using atomic_inc()/atomic_dec() for each
> > > do_shrink_slab() call will not impact so much.
> > 
> > But you could use SRCU..
> 
> Davidlohr has tried that already http://lkml.kernel.org/r/1434398602.1903.15.camel@xxxxxxxxxxxx
> and failed. Doing SRCU inside core kernel is not seen with a great
> support...

I can't actually find any objection in that thread.  What's the problem
Davidlohr ran into?