Re: [PATCH] mm: net: memcg accounting for TCP rx zerocopy

[Shakeel Butt]

On Wed, Jan 13, 2021 at 10:43 AM Roman Gushchin <guro@xxxxxx> wrote:
>
> On Tue, Jan 12, 2021 at 04:18:44PM -0800, Shakeel Butt wrote:
> > On Tue, Jan 12, 2021 at 4:12 PM Arjun Roy <arjunroy@xxxxxxxxxx> wrote:
> > >
> > > On Tue, Jan 12, 2021 at 3:48 PM Roman Gushchin <guro@xxxxxx> wrote:
> > > >
> > [snip]
> > > > Historically we have a corresponding vmstat counter to each charged page.
> > > > It helps with finding accounting/stastistics issues: we can check that
> > > > memory.current ~= anon + file + sock + slab + percpu + stack.
> > > > It would be nice to preserve such ability.
> > > >
> > >
> > > Perhaps one option would be to have it count as a file page, or have a
> > > new category.
> > >
> >
> > Oh these are actually already accounted for in NR_FILE_MAPPED.
>
> Well, it's confusing. Can't we fix this by looking at the new page memcg flag?

Yes we can. I am inclined more towards just using NR_FILE_PAGES (as
Arjun suggested) instead of adding a new metric.