Re: [RFC PATCH] memcg: use root_mem_cgroup when css is inherited

[Tejun Heo]

On Fri, Aug 19, 2022 at 10:08:59AM -0700, Shakeel Butt wrote:
> On Fri, Aug 19, 2022 at 9:29 AM Tejun Heo <tj@xxxxxxxxxx> wrote:
> >
> > On Fri, Aug 19, 2022 at 07:29:22PM +0800, zhaoyang.huang wrote:
> > > From: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx>
> > >
> > > It is observed in android system where per-app cgroup is demanded by freezer
> > > subsys and part of groups require memory control. The hierarchy could be simplized
> > > as bellowing where memory charged on group B abserved while we only want have
> > > group E's memory be controlled and B's descendants compete freely for memory.
> > > This should be the consequences of unified hierarchy.
> > > Under this scenario, less efficient memory reclaim is observed when comparing
> > > with no memory control. It is believed that multi LRU scanning introduces some
> > > of the overhead. Furthermore, page thrashing is also heavier than global LRU
> > > which could be the consequences of partial failure of WORKINGSET mechanism as
> > > LRU is too short to protect the active pages.
> > >
> > > A(subtree_control = memory) - B(subtree_control = NULL) - C()
> > >                                                       \ D()
> > >                           - E(subtree_control = memory) - F()
> > >                                                         \ G()
> > >
> > > Signed-off-by: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx>
> >
> > Just in case it wasn't clear.
> >
> > Nacked-by: Tejun Heo <tj@xxxxxxxxxx>
> >
> > Thanks.
> >
> 
> Was there a previous discussion on this? The commit message is unreadable.

http://lkml.kernel.org/r/1660298966-11493-1-git-send-email-zhaoyang.huang@xxxxxxxxxx

Thanks.

-- 
tejun