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

From: Michal Hocko
Date: Mon Nov 20 2017 - 04:25:34 EST


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...
--
Michal Hocko
SUSE Labs