Re: [RESEND PATCH v2 01/12] mm: memcontrol: fix NR_ANON_THPS account

[Johannes Weiner]

On Thu, Dec 10, 2020 at 05:00:47PM +0100, Johannes Weiner wrote:
> On Sun, Dec 06, 2020 at 06:14:40PM +0800, Muchun Song wrote:
> > The unit of NR_ANON_THPS is HPAGE_PMD_NR already. So it should inc/dec
> > by one rather than nr_pages.
> 
> This is a real bug, thanks for catching it.
> 
> However, your patch changes the user-visible output of /proc/vmstat!
> 
> NR_ANON_THPS isn't just used by memcg, it's a generic accounting item
> of the memory subsystem. See this from the Fixes:-patch:
> 
> -                       __inc_node_page_state(page, NR_ANON_THPS);
> +                       __inc_lruvec_page_state(page, NR_ANON_THPS);
> 
> While we've considered /proc/vmstat less official than other files
> like meminfo, and have in the past freely added and removed items,
> changing the unit of an existing one is not going to work.

Argh, I hit send instead of cancel after noticing that I misread your
patch completely. Scratch what I wrote above.