Re: [PATCH v3 2/2] alloc_tag: mark pages reserved during CMA activation as not tagged

[Suren Baghdasaryan <surenb@google.com>]

On Tue, Aug 13, 2024 at 8:09 AM David Hildenbrand <david@redhat.com> wrote:
>
> On 13.08.24 17:07, Suren Baghdasaryan wrote:
> > During CMA activation, pages in CMA area are prepared and then freed
> > without being allocated. This triggers warnings when memory allocation
> > debug config (CONFIG_MEM_ALLOC_PROFILING_DEBUG) is enabled. Fix this
> > by marking these pages not tagged before freeing them.
> >
> > Fixes: d224eb0287fb ("codetag: debug: mark codetags for reserved pages as empty")
> > Signed-off-by: Suren Baghdasaryan <surenb@google.com>
> > Cc: stable@vger.kernel.org # v6.10
> > ---
> > Changes since v2 [1]:
> > - Add and use clear_page_tag_ref helper, per David Hildenbrand
> >
> > https://lore.kernel.org/all/20240812192428.151825-1-surenb@google.com/
> >
> >   mm/mm_init.c | 2 ++
> >   1 file changed, 2 insertions(+)
> >
> > diff --git a/mm/mm_init.c b/mm/mm_init.c
> > index 907c46b0773f..13c4060bb01a 100644
> > --- a/mm/mm_init.c
> > +++ b/mm/mm_init.c
> > @@ -2245,6 +2245,8 @@ void __init init_cma_reserved_pageblock(struct page *page)
> >
> >       set_pageblock_migratetype(page, MIGRATE_CMA);
> >       set_page_refcounted(page);
> > +     /* pages were reserved and not allocated */
> > +     clear_page_tag_ref(page);
> >       __free_pages(page, pageblock_order);
> >
> >       adjust_managed_page_count(page, pageblock_nr_pages);
>
> Acked-by: David Hildenbrand <david@redhat.com>

Thanks!

>
> --
> Cheers,
>
> David / dhildenb
>