Re: [PATCH v14 035/138] mm/memcg: Use the node id in mem_cgroup_update_tree()

Matthew Wilcox
2021-08-13T18:57:38Z

On Tue, Aug 10, 2021 at 09:06:52PM +0100, David Howells wrote:
> Matthew Wilcox (Oracle) <willy@infradead.org> wrote:
>
> > By using the node id in mem_cgroup_update_tree(), we can delete
> > soft_limit_tree_from_page() and mem_cgroup_page_nodeinfo(). Saves 42
> > bytes of kernel text on my config.
> >
> > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> > Acked-by: Michal Hocko <mhocko@suse.com>
> > Acked-by: Johannes Weiner <hannes@cmpxchg.org>
> > Reviewed-by: Christoph Hellwig <hch@lst.de>
>
> Reviewed-by: David Howells <dhowells@redhat.com>
>
> Though I wonder if:
>
> > - mz = mem_cgroup_page_nodeinfo(memcg, page);
> > + mz = memcg->nodeinfo[nid];
>
> should still have some sort of wrapper function.

I was asked to remove the wrapper function as it didn't provide enough
utility to warrant the indirection.