Re: [PATCH v2 2/2] mm: multi-gen LRU: fix NULL lruvec->pgdat deref in get_lruvec()

[Barry Song]

On Tue, Oct 20, 2026 at 9:02 AM Siddharth Chintamaneni
<sidchintamaneni@xxxxxxxxx> wrote:
>
[...]
> >
> > Thanks!
> > I guess you mean the following:
> >
> > -module_init(kswapd_init)
> > +//module_init(kswapd_init)
> >
> > Yes, I can reproduce it with the above as well.
> >
> > But kswapd_init() is definitely called before we enter userspace,
> > so this doesn't seem to be an issue here?
> >
>
> Looking at the callee sites of get_lruvec, all of them happen after
> boot. So it should be fine. Anyway code clean up will address the
> issue.
>
> > So I feel there is no bug here, but this cleanup is still welcome.
>
> Are you ok with the patch as is, or would you recommend  changing the
> callsite of get_lruvec to mem_cgroup_lruvec?

Overall, I'd be happy to see MGLRU-specific code being removed.

If possible, could we split this into a two-patch series? The
first patch would be this one, and the second would drop
get_lruvec().

In any case, if this isn't a bug fix, there's no need for a Fixes tag or
a stable backport.

BTW, I've been struggling to understand why MGLRU introduced
its own version in the first place. Maybe your follow-up
patchset will help clarify that :-)

Best Regards
Barry