Re: [PATCH v4 03/17] mm/memcg: add folio-based lruvec live helper

[Kairui Song]

On Fri, Oct 16, 2026 at 3:11 AM Harry Yoo <harry@xxxxxxxxxx> wrote:
>
> On Fri, Oct 16, 2026 at 02:15:52AM +0800, Kairui Song via B4 Relay wrote:
> > From: Kairui Song <kasong@xxxxxxxxxxx>
> >
> > Add a helper that resolves a stable lruvec for a folio under RCU
> > without taking the lruvec lock.  It takes a folio directly so the
> > lruvec lookup happens inside the RCU read-side critical section,
> > which a lruvec-based interface cannot guarantee.
> >
> > No functional change.
> >
> > Tested-by: zhaozhengzhuo <zhaozhengzhuo@xxxxxxxxxxxxx>
> > Signed-off-by: Kairui Song <kasong@xxxxxxxxxxx>
> > ---
>
> This new helper is doing the the same thing as what
> get_non_dying_memcg_start/end() do.
>

Hi Harry, thanks for letting me know, I wasn't aware this helper
exists, this series started before the re-planting work, so I missed
it.

But it's a bit different though, get_non_dying_memcg_start assumes the
caller holds a reference to memcg, while folio_lruvec_live_get only
assumes the caller holds an reference to the folio.

I'll check if I can deduplicate it though.