Re: [akpm-mm:mm-stable 72/140] arch/sparc/mm/init_64.c:2582:16: error: implicit declaration of function 'vmemmap_pgd_populate'; did you mean 'vmemmap_populate'?

[Philip Li <philip.li@intel.com>]

On Tue, Mar 24, 2026 at 08:27:54PM -0700, Andrew Morton wrote:
> On Wed, 25 Mar 2026 11:10:49 +0800 kernel test robot <lkp@intel.com> wrote:
> 
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-stable
> > head:   e393ce79b3cf63c2810be882eb6e531a54f520f4
> > commit: e504282091c8e4dc4f945c89d9b44ac2e0bfe504 [72/140] mm: convert vmemmap_p?d_populate() to static functions
> > config: sparc-randconfig-001-20260325 (https://download.01.org/0day-ci/archive/20260325/202603251147.CtgepAeH-lkp@intel.com/config)
> > compiler: sparc64-linux-gcc (GCC) 8.5.0
> > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260325/202603251147.CtgepAeH-lkp@intel.com/reproduce)
> > 
> > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > the same patch/commit), kindly add following tags
> > | Reported-by: kernel test robot <lkp@intel.com>
> > | Closes: https://lore.kernel.org/oe-kbuild-all/202603251147.CtgepAeH-lkp@intel.com/
> > 
> > All error/warnings (new ones prefixed by >>):
> > 
> >    arch/sparc/mm/init_64.c: In function 'sun4v_linear_pte_xor_finalize':
> >    arch/sparc/mm/init_64.c:2202:16: warning: variable 'pagecv_flag' set but not used [-Wunused-but-set-variable]
> >      unsigned long pagecv_flag;
> >                    ^~~~~~~~~~~
> >    arch/sparc/mm/init_64.c: In function 'vmemmap_populate':
> > >> arch/sparc/mm/init_64.c:2582:16: error: implicit declaration of function 'vmemmap_pgd_populate'; did you mean 'vmemmap_populate'? [-Werror=implicit-function-declaration]
> >       pgd_t *pgd = vmemmap_pgd_populate(vstart, node);
> >                    ^~~~~~~~~~~~~~~~~~~~
> 
> Oh fecal matter.  Seven weeks in mm.git and then seven milliseconds
> after I move it into mm-stable, we get this.
> 
> The coincidence is too great.  I assume Kernel Test Robot is somehow
> treating the mm-stable differently from other branches?  Can we please
> not do that?

Sorry for this "coincidence", the bot does treat all branches equally and
there's no special handling of mm-stable. One possibility is the randconfig
is just generated on 20260325 "sparc-randconfig-001-20260325", which is able
to expose this issue for sparc arch.

> 
> Thanks, I dropped the patch.  Chengkaitao, please redo and resend after
> 7.1-rc1.
> 
>