Re: [PATCH v6 06/19] mm: memcg/slab: obj_cgroup API

Roman Gushchin
2020-06-19T22:57:12Z

On Fri, Jun 19, 2020 at 03:16:44PM -0700, Shakeel Butt wrote:
> On Fri, Jun 19, 2020 at 2:38 PM Roman Gushchin <guro@fb.com> wrote:
> >
> [snip]
> > > > memcg->objcg is rcu protected.
> > > > objcg->memcg is a raw pointer, which is always pointing at a memory
> > > > cgroup, but can be atomically swapped to the parent memory cgroup. So
> > > > the caller
> > >
> > > What type of caller? The allocator?
> >
> > Basically whoever uses the pointer. Is it better to s/caller/user?
> >
>
> Yes 'user' feels better.
>
> > >
> [...]
> > >
> > > The normal stock can go to 32*nr_cpus*PAGE_SIZE. I am wondering if
> > > just PAGE_SIZE is too less for obj stock.
> >
> > It works on top of the current stock of 32 pages, so it can grab these
> > 32 pages without any atomic operations. And it should be easy to increase
> > this limit if we'll see any benefits.
> >
> > Thank you for looking into the patchset!
> >
> > Andrew, can you, please, squash the following fix based on Shakeel's suggestions?
> > Thanks!
> >
> > --
>
> For the following squashed into the original patch:
>
> Reviewed-by: Shakeel Butt <shakeelb@google.com>

Thank you!