Re: [PATCH v3] mm: introduce a new page type for page pool in page type

Hi Byungchul,

kernel test robot noticed the following build warnings:

[auto build test WARNING on akpm-mm/mm-everything]

url:    https://github.com/intel-lab-lkp/linux/commits/Byungchul-Park/mm-introduce-a-new-page-type-for-page-pool-in-page-type/20260210-194920
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20260210114712.55072-1-byungchul%40sk.com
patch subject: [PATCH v3] mm: introduce a new page type for page pool in page type
config: microblaze-randconfig-r134-20260211 (https://download.01.org/0day-ci/archive/20260211/202602112054.QKfqC0UR-lkp@intel.com/config)
compiler: microblaze-linux-gcc (GCC) 15.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260211/202602112054.QKfqC0UR-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 [off-list ref]
| Closes: https://lore.kernel.org/oe-kbuild-all/202602112054.QKfqC0UR-lkp@intel.com/ (local)

sparse warnings: (new ones prefixed by >>)
   net/core/skbuff.c: note: in included file:

quoted

net/core/netmem_priv.h:21:20: sparse: sparse: cast to restricted netmem_ref
net/core/netmem_priv.h:21:20: sparse: sparse: cast to restricted netmem_ref

   net/core/skbuff.c: note: in included file (through include/linux/skbuff.h, include/net/net_namespace.h, include/linux/inet.h):
   include/net/checksum.h:33:39: sparse: sparse: incorrect type in argument 3 (different base types) @@     expected restricted __wsum [usertype] sum @@     got unsigned int @@
   include/net/checksum.h:33:39: sparse:     expected restricted __wsum [usertype] sum
   include/net/checksum.h:33:39: sparse:     got unsigned int
--

quoted

net/core/page_pool.c:715:20: sparse: sparse: cast to restricted netmem_ref

   net/core/page_pool.c:739:20: sparse: sparse: cast to restricted netmem_ref

vim +21 net/core/netmem_priv.h

    10	
    11	static inline bool netmem_is_pp(netmem_ref netmem)
    12	{
    13		netmem_ref clr_ref;
    14	
    15		/* XXX: Now that the offset of page_type is shared between
    16		 * struct page and net_iov, just cast the netmem to struct page
    17		 * unconditionally by clearing NET_IOV if any, no matter whether
    18		 * it comes from struct net_iov or struct page.  This should be
    19		 * adjusted once the offset is no longer shared.
    20		 */
  > 21		clr_ref = (netmem_ref)((__force unsigned long)netmem & ~NET_IOV);
    22		return PageNetpp(__netmem_to_page(clr_ref));
    23	}
    24	

-- 
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