Hi Jordan, kernel test robot noticed the following build warnings:
[auto build test WARNING on f8f9c1f4d0c7a64600e2ca312dec824a0bc2f1da] url: https://github.com/intel-lab-lkp/linux/commits/Jordan-Niethe/mm-migrate_device-Add-migrate-PFN-flag-to-track-device-private-pages/20251231-123453 base: f8f9c1f4d0c7a64600e2ca312dec824a0bc2f1da patch link: https://lore.kernel.org/r/20251231043154.42931-9-jniethe%40nvidia.com patch subject: [PATCH v1 8/8] mm: Remove device private pages from the physical address space config: s390-allnoconfig (https://download.01.org/0day-ci/archive/20260103/[email protected]/config) compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project f43d6834093b19baf79beda8c0337ab020ac5f17) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260103/[email protected]/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 <[email protected]> | Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/ All warnings (new ones prefixed by >>): In file included from arch/s390/purgatory/purgatory.c:10: In file included from include/linux/kexec.h:18: In file included from include/linux/vmcore_info.h:6: In file included from include/linux/elfcore.h:11: In file included from include/linux/ptrace.h:10: In file included from include/linux/pid_namespace.h:7: In file included from include/linux/mm.h:33: >> include/linux/memremap.h:148:2: warning: field '' with variable sized type >> 'union dev_pagemap::(anonymous at include/linux/memremap.h:148:2)' not at >> the end of a struct or class is a GNU extension >> [-Wgnu-variable-sized-type-not-at-end] 148 | union { | ^ 1 warning generated. vim +148 include/linux/memremap.h 514caf23a70fd6 Christoph Hellwig 2019-06-26 113 9476df7d80dfc4 Dan Williams 2016-01-15 114 /** 9476df7d80dfc4 Dan Williams 2016-01-15 115 * struct dev_pagemap - metadata for ZONE_DEVICE mappings 4b94ffdc4163ba Dan Williams 2016-01-15 116 * @altmap: pre-allocated/reserved memory for vmemmap allocations 5c2c2587b13235 Dan Williams 2016-01-15 117 * @ref: reference count that pins the devm_memremap_pages() mapping b80892ca022e9e Christoph Hellwig 2021-10-28 118 * @done: completion for @ref 0c32c9f7a58e77 John Groves 2024-02-05 119 * @type: memory type: see MEMORY_* above in memremap.h 514caf23a70fd6 Christoph Hellwig 2019-06-26 120 * @flags: PGMAP_* flags to specify defailed behavior c4386bd8ee3a92 Joao Martins 2022-01-14 121 * @vmemmap_shift: structural definition of how the vmemmap page metadata c4386bd8ee3a92 Joao Martins 2022-01-14 122 * is populated, specifically the metadata page order. c4386bd8ee3a92 Joao Martins 2022-01-14 123 * A zero value (default) uses base pages as the vmemmap metadata c4386bd8ee3a92 Joao Martins 2022-01-14 124 * representation. A bigger value will set up compound struct pages c4386bd8ee3a92 Joao Martins 2022-01-14 125 * of the requested order value. 1e240e8d4a7d92 Christoph Hellwig 2019-06-26 126 * @ops: method table f894ddd5ff01d3 Christoph Hellwig 2020-03-16 127 * @owner: an opaque pointer identifying the entity that manages this f894ddd5ff01d3 Christoph Hellwig 2020-03-16 128 * instance. Used by various helpers to make sure that no f894ddd5ff01d3 Christoph Hellwig 2020-03-16 129 * foreign ZONE_DEVICE memory is accessed. 0386df765967ce Jordan Niethe 2025-12-31 130 * @nr_range: number of ranges to be mapped. Always == 1 for 0386df765967ce Jordan Niethe 2025-12-31 131 * MEMORY_DEVICE_PRIVATE. 0386df765967ce Jordan Niethe 2025-12-31 132 * @range: range to be mapped when nr_range == 1. Used as an output param for 0386df765967ce Jordan Niethe 2025-12-31 133 * MEMORY_DEVICE_PRIVATE. b7b3c01b191596 Dan Williams 2020-10-13 134 * @ranges: array of ranges to be mapped when nr_range > 1 0386df765967ce Jordan Niethe 2025-12-31 135 * @nr_pages: number of pages requested to be mapped for MEMORY_DEVICE_PRIVATE. 0386df765967ce Jordan Niethe 2025-12-31 136 * @pages: array of nr_pages initialized for MEMORY_DEVICE_PRIVATE. 9476df7d80dfc4 Dan Williams 2016-01-15 137 */ 9476df7d80dfc4 Dan Williams 2016-01-15 138 struct dev_pagemap { e7744aa25cffe2 Logan Gunthorpe 2017-12-29 139 struct vmem_altmap altmap; b80892ca022e9e Christoph Hellwig 2021-10-28 140 struct percpu_ref ref; 24917f6b1041a7 Christoph Hellwig 2019-06-26 141 struct completion done; 5042db43cc26f5 Jérôme Glisse 2017-09-08 142 enum memory_type type; 514caf23a70fd6 Christoph Hellwig 2019-06-26 143 unsigned int flags; c4386bd8ee3a92 Joao Martins 2022-01-14 144 unsigned long vmemmap_shift; 1e240e8d4a7d92 Christoph Hellwig 2019-06-26 145 const struct dev_pagemap_ops *ops; f894ddd5ff01d3 Christoph Hellwig 2020-03-16 146 void *owner; b7b3c01b191596 Dan Williams 2020-10-13 147 int nr_range; b7b3c01b191596 Dan Williams 2020-10-13 @148 union { b7b3c01b191596 Dan Williams 2020-10-13 149 struct range range; 06919d226d0113 Gustavo A. R. Silva 2022-09-03 150 DECLARE_FLEX_ARRAY(struct range, ranges); b7b3c01b191596 Dan Williams 2020-10-13 151 }; 0386df765967ce Jordan Niethe 2025-12-31 152 unsigned long nr_pages; 0386df765967ce Jordan Niethe 2025-12-31 153 struct page *pages; 9476df7d80dfc4 Dan Williams 2016-01-15 154 }; 9476df7d80dfc4 Dan Williams 2016-01-15 155 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
