Re: [PATCH] memblock: use for_each_zone() in reset_all_zones_managed_pages()

[Mike Rapoport <rppt@kernel.org>]

On Thu, Sep 10, 2026 at 11:35:41PM +0900, Sang-Heon Jeon wrote:
> On Thu, Sep 10, 2026 at 9:19 PM Sang-Heon Jeon <ekffu200098@gmail.com> wrote:
> >
> > On Thu, Sep 10, 2026 at 7:13 PM Mike Rapoport <rppt@kernel.org> wrote:
> > >
> > > On 2026-09-10 12:58 +0300, Mike Rapoport wrote:
> > > > On Wed, 09 Sep 2026 01:57:32 +0900, Sang-Heon Jeon wrote:
> > > > > memblock: use for_each_zone() in reset_all_zones_managed_pages()
> > > >
> > > > Applied to for-next branch of memblock.git tree, thanks!
> > > >
> > > > [1/1] memblock: use for_each_zone() in reset_all_zones_managed_pages()
> > > >       commit: 0876b2d8794913c867a1bb0dc3fd22ea1c5f0a95
> > > >
> > > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock
> > > > branch: for-next
> > >
> > > Hmm, I was too hasty.
> > > This breaks mmemblock tests, so I dropped it for now.
> >
> > Sorry for the noise. I missed it. I will keep it in mind next time.
> > Just give me a second to check.
> 
> With the below fixes, tests will be fine again. Is it okay to send the
> v2 patchset with below fixes?

memblock tests do not cover late parts of mm initialization, I believe it
would be fine to just define for_each_zone() to a nop.
 
> diff --git a/tools/testing/memblock/linux/mmzone.h
> b/tools/testing/memblock/linux/mmzone.h
> index 8d934ff5b080..631fe07923e7 100644
> --- a/tools/testing/memblock/linux/mmzone.h
> +++ b/tools/testing/memblock/linux/mmzone.h
> @@ -7,13 +7,20 @@
> 
>  struct pglist_data *first_online_pgdat(void);
>  struct pglist_data *next_online_pgdat(struct pglist_data *pgdat);
> +struct zone *next_zone(struct zone *zone);
> 
>  #define for_each_online_pgdat(pgdat)                   \
>         for (pgdat = first_online_pgdat();              \
>              pgdat;                                     \
>              pgdat = next_online_pgdat(pgdat))
> 
> +#define for_each_zone(zone)                            \
> +       for (zone = (first_online_pgdat())->node_zones; \
> +            zone;                                      \
> +            zone = next_zone(zone))
> +
>  enum zone_type {
> +       ZONE_NORMAL,
>         __MAX_NR_ZONES
>  };
> 
> @@ -27,6 +34,7 @@ enum zone_type {
>  #define pageblock_start_pfn(pfn)       ALIGN_DOWN((pfn), pageblock_nr_pages)
> 
>  struct zone {
> +       struct pglist_data      *zone_pgdat;
>         atomic_long_t           managed_pages;
>  };
> 
> diff --git a/tools/testing/memblock/mmzone.c b/tools/testing/memblock/mmzone.c
> index e719450f81cb..e73848bdc8d6 100644
> --- a/tools/testing/memblock/mmzone.c
> +++ b/tools/testing/memblock/mmzone.c
> @@ -1,9 +1,15 @@
>  // SPDX-License-Identifier: GPL-2.0-or-later
>  #include <linux/mmzone.h>
> 
> +static pg_data_t dummy_pgdat = {
> +       .node_zones = {
> +               [0 ... MAX_NR_ZONES - 1] = { .zone_pgdat = &dummy_pgdat },
> +       },
> +};
> +
>  struct pglist_data *first_online_pgdat(void)
>  {
> -       return NULL;
> +       return &dummy_pgdat;
>  }
> 
>  struct pglist_data *next_online_pgdat(struct pglist_data *pgdat)
> @@ -11,6 +17,22 @@ struct pglist_data *next_online_pgdat(struct
> pglist_data *pgdat)
>         return NULL;
>  }
> 
> +struct zone *next_zone(struct zone *zone)
> +{
> +       pg_data_t *pgdat = zone->zone_pgdat;
> +
> +       if (zone < pgdat->node_zones + MAX_NR_ZONES - 1)
> +               zone++;
> +       else {
> +               pgdat = next_online_pgdat(pgdat);
> +               if (pgdat)
> +                       zone = pgdat->node_zones;
> +               else
> +                       zone = NULL;
> +       }
> +       return zone;
> +}
> +
>  void atomic_long_set(atomic_long_t *v, long i)
>  {
>  }
> 
> > > > --
> > > > Sincerely yours,
> > > > Mike.
> > > >
> > > >
> > > >
> > > >
> > > >
> > >
> > >
> >
> > Best regards
> > Sang-Heon Jeon
> 
> Best regards,
> Sang-Heon Jeon

-- 
Sincerely yours,
Mike.