Re: [PATCH v3] smaps: Report PMD page size for pure PMD mappings

[kernel test robot <lkp@intel.com>]

:::::: 
:::::: Manual check reason: "__compiletime_assert_NNN"
:::::: 

BCC: lkp@intel.com
CC: llvm@lists.linux.dev
CC: oe-kbuild-all@lists.linux.dev
In-Reply-To: <20260303201556.107960-1-ak@linux.intel.com>
References: <20260303201556.107960-1-ak@linux.intel.com>
TO: Andi Kleen <ak@linux.intel.com>
TO: linux-mm@kvack.org
CC: akpm@linux-foundation.org
CC: Andi Kleen <ak@linux.intel.com>

Hi Andi,

kernel test robot noticed the following build errors:

[auto build test ERROR on brauner-vfs/vfs.all]
[also build test ERROR on akpm-mm/mm-everything linus/master v7.0-rc2 next-20260303]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Andi-Kleen/smaps-Report-PMD-page-size-for-pure-PMD-mappings/20260304-041922
base:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git vfs.all
patch link:    https://lore.kernel.org/r/20260303201556.107960-1-ak%40linux.intel.com
patch subject: [PATCH v3] smaps: Report PMD page size for pure PMD mappings
:::::: branch date: 10 hours ago
:::::: commit date: 10 hours ago
config: hexagon-allnoconfig (https://download.01.org/0day-ci/archive/20260304/202603041448.j9gaSbUi-lkp@intel.com/config)
compiler: clang version 23.0.0git (https://github.com/llvm/llvm-project 9a109fbb6e184ec9bcce10615949f598f4c974a9)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260304/202603041448.j9gaSbUi-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/r/202603041448.j9gaSbUi-lkp@intel.com/

All errors (new ones prefixed by >>):

>> fs/proc/task_mmu.c:1390:8: error: call to '__compiletime_assert_405' declared with 'error' attribute: BUILD_BUG failed
    1390 |                 ps = HPAGE_PMD_SIZE;
         |                      ^
   include/linux/huge_mm.h:120:34: note: expanded from macro 'HPAGE_PMD_SIZE'
     120 | #define HPAGE_PMD_SIZE  ((1UL) << HPAGE_PMD_SHIFT)
         |                                   ^
   include/linux/huge_mm.h:113:28: note: expanded from macro 'HPAGE_PMD_SHIFT'
     113 | #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
         |                            ^
   include/linux/build_bug.h:59:21: note: expanded from macro 'BUILD_BUG'
      59 | #define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed")
         |                     ^
   note: (skipping 2 expansions in backtrace; use -fmacro-backtrace-limit=0 to see all)
   include/linux/compiler_types.h:694:2: note: expanded from macro '_compiletime_assert'
     694 |         __compiletime_assert(condition, msg, prefix, suffix)
         |         ^
   include/linux/compiler_types.h:687:4: note: expanded from macro '__compiletime_assert'
     687 |                         prefix ## suffix();                             \
         |                         ^
   <scratch space>:79:1: note: expanded from here
      79 | __compiletime_assert_405
         | ^
   1 error generated.


vim +1390 fs/proc/task_mmu.c

f1547959d9efd0 Vlastimil Babka   2018-08-21  1369  
8e68d689afe328 Vlastimil Babka   2018-08-21  1370  static int show_smap(struct seq_file *m, void *v)
8e68d689afe328 Vlastimil Babka   2018-08-21  1371  {
8e68d689afe328 Vlastimil Babka   2018-08-21  1372  	struct vm_area_struct *vma = v;
860a2e7fa4a186 Alexey Dobriyan   2023-09-29  1373  	struct mem_size_stats mss = {};
9378536cc887d4 Andi Kleen        2026-03-03  1374  	unsigned ps;
8e68d689afe328 Vlastimil Babka   2018-08-21  1375  
03b4b1149308b0 Chinwen Chang     2020-10-13  1376  	smap_gather_stats(vma, &mss, 0);
4752c369789250 Matt Mackall      2008-02-04  1377  
871305bb202808 Vlastimil Babka   2018-08-21  1378  	show_map_vma(m, vma);
4752c369789250 Matt Mackall      2008-02-04  1379  
d1be35cb6f9697 Andrei Vagin      2018-04-10  1380  	SEQ_PUT_DEC("Size:           ", vma->vm_end - vma->vm_start);
d1be35cb6f9697 Andrei Vagin      2018-04-10  1381  	SEQ_PUT_DEC(" kB\nKernelPageSize: ", vma_kernel_pagesize(vma));
9378536cc887d4 Andi Kleen        2026-03-03  1382  	ps = vma_mmu_pagesize(vma);
9378536cc887d4 Andi Kleen        2026-03-03  1383  	/*
9378536cc887d4 Andi Kleen        2026-03-03  1384  	 * When the mapping is only PMD THP report the correct page size.
9378536cc887d4 Andi Kleen        2026-03-03  1385  	 * When multiple pages are there the user has to figure it out
9378536cc887d4 Andi Kleen        2026-03-03  1386  	 * from other fields.
9378536cc887d4 Andi Kleen        2026-03-03  1387  	 */
9378536cc887d4 Andi Kleen        2026-03-03  1388  	if (mss.shmem_thp + mss.file_thp + mss.anonymous_thp == mss.resident &&
9378536cc887d4 Andi Kleen        2026-03-03  1389  	    mss.resident)
9378536cc887d4 Andi Kleen        2026-03-03 @1390  		ps = HPAGE_PMD_SIZE;
9378536cc887d4 Andi Kleen        2026-03-03  1391  	SEQ_PUT_DEC(" kB\nMMUPageSize:    ", ps);
d1be35cb6f9697 Andrei Vagin      2018-04-10  1392  	seq_puts(m, " kB\n");
d1be35cb6f9697 Andrei Vagin      2018-04-10  1393  
ee2ad71b0756e9 Luigi Semenzato   2019-07-11  1394  	__show_smap(m, &mss, false);
f1547959d9efd0 Vlastimil Babka   2018-08-21  1395  
daa60ae64c6587 Hugh Dickins      2023-08-14  1396  	seq_printf(m, "THPeligible:    %8u\n",
1f1c061089dcd2 David Hildenbrand 2025-08-15  1397  		   !!thp_vma_allowable_orders(vma, vma->vm_flags, TVA_SMAPS,
1f1c061089dcd2 David Hildenbrand 2025-08-15  1398  					      THP_ORDERS_ALL));
7635d9cbe8327e Michal Hocko      2018-12-28  1399  
27cca866e3fce0 Ram Pai           2018-04-13  1400  	if (arch_pkeys_enabled())
27cca866e3fce0 Ram Pai           2018-04-13  1401  		seq_printf(m, "ProtectionKey:  %8u\n", vma_pkey(vma));
834f82e2aa9a8e Cyrill Gorcunov   2012-12-17  1402  	show_smap_vma_flags(m, vma);
258f669e7e88c1 Vlastimil Babka   2018-08-21  1403  
258f669e7e88c1 Vlastimil Babka   2018-08-21  1404  	return 0;
258f669e7e88c1 Vlastimil Babka   2018-08-21  1405  }
258f669e7e88c1 Vlastimil Babka   2018-08-21  1406  

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