Re: [PATCH v5 02/22] liveupdate: luo_core: integrate with KHO

From: Mike Rapoport

Date: Wed Nov 12 2025 - 05:21:34 EST


On Tue, Nov 11, 2025 at 03:42:24PM -0500, Pasha Tatashin wrote:
> On Tue, Nov 11, 2025 at 3:39 PM Pasha Tatashin
> <pasha.tatashin@xxxxxxxxxx> wrote:
> >
> > > > kho_memory_init();
> > > >
> > > > + /* Live Update should follow right after KHO is initialized */
> > > > + liveupdate_init();
> > > > +
> > >
> > > Why do you think it should be immediately after kho_memory_init()?
> > > Any reason this can't be called from start_kernel() or even later as an
> > > early_initcall() or core_initall()?
> >
> > Unfortunately, no, even here it is too late, and we might need to find
> > a way to move the kho_init/liveupdate_init earlier. We must be able to
> > preserve HugeTLB pages, and those are reserved earlier in boot.
>
> Just to clarify: liveupdate_init() is needed to start using:
> liveupdate_flb_incoming_* API, and FLB data is needed during HugeTLB
> reservation.

Since flb is "file-lifecycle-bound", it implies *file*. Early memory
reservations in hugetlb are not bound to files, they end up in file objects
way later.

So I think for now we can move liveupdate_init() later in boot and we will
solve the problem of hugetlb reservations when we add support for hugetlb.

> Pasha

--
Sincerely yours,
Mike.