Re: [akpm-mm:mm-new 61/87] drivers/cxl/core/region.c:2437:22: error: invalid use of undefined type 'struct node_notify'

[Andrew Morton <akpm@linux-foundation.org>]

On Fri,  6 Jun 2025 12:23:45 -0700 Joshua Hahn <joshua.hahnjy@gmail.com> wrote:

> On Sat, 7 Jun 2025 00:19:17 +0800 kernel test robot <lkp@intel.com> wrote:
> 
> > Hi Oscar,
> > 
> > FYI, the error/warning was bisected to this commit, please ignore it if it's irrelevant.
> > 
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-new
> > head:   b9f05ab60cb240a64e898221de50a037553840c7
> > commit: 7bd79eaa2076cde601d828532a09ea50e20a976f [61/87] drivers,cxl: use node-notifier instead of memory-notifier
> > config: loongarch-randconfig-001-20250606 (https://download.01.org/0day-ci/archive/20250607/202506070030.otNokpsc-lkp@intel.com/config)
> > compiler: loongarch64-linux-gcc (GCC) 15.1.0
> > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250607/202506070030.otNokpsc-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/202506070030.otNokpsc-lkp@intel.com/
> > 
> > All errors (new ones prefixed by >>):
> > 
> >    drivers/cxl/core/region.c: In function 'cxl_region_perf_attrs_callback':
> > >> drivers/cxl/core/region.c:2437:22: error: invalid use of undefined type 'struct node_notify'
> >     2437 |         int nid = mnb->nid;
> >          |                      ^~
> >    drivers/cxl/core/region.c:2440:46: error: 'NODE_ADDED_FIRST_MEMORY' undeclared (first use in this function)
> >     2440 |         if (nid == NUMA_NO_NODE || action != NODE_ADDED_FIRST_MEMORY)
> >          |                                              ^~~~~~~~~~~~~~~~~~~~~~~
> >    drivers/cxl/core/region.c:2440:46: note: each undeclared identifier is reported only once for each function it appears in
> >    drivers/cxl/core/region.c: In function 'shutdown_notifiers':
> >    drivers/cxl/core/region.c:3487:9: error: implicit declaration of function 'unregister_node_notifier'; did you mean 'unregister_module_notifier'? [-Wimplicit-function-declaration]
> >     3487 |         unregister_node_notifier(&cxlr->node_notifier);
> >          |         ^~~~~~~~~~~~~~~~~~~~~~~~
> >          |         unregister_module_notifier
> >    drivers/cxl/core/region.c: In function 'cxl_region_probe':
> >    drivers/cxl/core/region.c:3528:9: error: implicit declaration of function 'register_node_notifier'; did you mean 'register_module_notifier'? [-Wimplicit-function-declaration]
> >     3528 |         register_node_notifier(&cxlr->node_notifier);
> >          |         ^~~~~~~~~~~~~~~~~~~~~~
> >          |         register_module_notifier
> 
> >From what I can see, it seems like struct node_notify is conditionally
> defined under #ifdef CONFIG_MEMORY_HOTPLUG, but the callsite unconditionally
> declares struct node_notify *mnb = arg.

Yup.  Also,

-	struct memory_notify *mnb = arg;
+	struct node_notify *mnb = arg;

`mnb' is no longer an appropriate identifier!  Maybe nnb?