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

[Tetsuo Handa]

Christoph Hellwig wrote:
> On Mon, Nov 20, 2017 at 10:42:37AM +0100, Michal Hocko wrote:
> > The patch has been dropped because allnoconfig failed to compile back
> > then http://lkml.kernel.org/r/CAP=VYLr0rPWi1aeuk4w1On9CYRNmnEWwJgGtaX=wEvGaBURtrg@xxxxxxxxxxxxxx
> > I have problem to find the follow up discussion though. The main
> > argument was that SRC is not generally available and so the core
> > kernel should rely on it.
> 
> Paul,
> 
> isthere any good reason to not use SRCU in the core kernel and
> instead try to reimplement it using atomic counters?

CONFIG_SRCU was added in order to save system size. There are users who run Linux on very
small systems ( https://www.elinux.org/images/5/52/Status-of-embedded-Linux-2017-09-JJ62.pdf ).

Also, atomic counters are not mandatory for shrinker case; e.g.
http://lkml.kernel.org/r/201711161956.EBF57883.QFFMOLOVSOHJFt@xxxxxxxxxxxxxxxxxxx .