[openeuler:OLK-5.10 2740/2740] mm/page_alloc.c:3036:6: warning: no previous prototype for '__drain_all_pages' - Kernel

16 Feb 2025

      Hi Vlastimil,

FYI, the error/warning still remains.

tree:   https://gitee.com/openeuler/kernel.git OLK-5.10
head:   e804018e3930644594e31fd711068f5d48ae05af
commit: e037ee4a8deaff7c579618c0aba1f066d6d14b11 [2740/2740] mm, page_alloc: disable pcplists during memory offline
config: x86_64-buildonly-randconfig-002-20250216 (https://download.01.org/0day-ci/archive/20250216/202502161355.thfOP2mL-lkp@i...)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250216/202502161355.thfOP2mL-lkp@i...)

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/202502161355.thfOP2mL-lkp@intel.com/

All warnings (new ones prefixed by >>):
...
...
mm/page_alloc.c:3036:6: warning: no previous prototype for '__drain_all_pages' [-Wmissing-prototypes]
    3036 | void __drain_all_pages(struct zone *zone, bool force_all_cpus)
         |      ^~~~~~~~~~~~~~~~~
   mm/page_alloc.c:3586:15: warning: no previous prototype for 'should_fail_alloc_page' [-Wmissing-prototypes]
    3586 | noinline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
         |               ^~~~~~~~~~~~~~~~~~~~~~
   mm/page_alloc.c:6497:20: warning: no previous prototype for 'memmap_init' [-Wmissing-prototypes]
    6497 | void __init __weak memmap_init(void)
         |                    ^~~~~~~~~~~
   mm/page_alloc.c:6535:23: warning: no previous prototype for 'arch_memmap_init' [-Wmissing-prototypes]
    6535 | void __meminit __weak arch_memmap_init(unsigned long size, int nid,
         |                       ^~~~~~~~~~~~~~~~
mm/page_alloc.c:6634:6: warning: no previous prototype for '__zone_set_pageset_high_and_batch' [-Wmissing-prototypes]
    6634 | void __zone_set_pageset_high_and_batch(struct zone *zone, unsigned long high,
         |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   mm/page_alloc.c: In function 'mem_init_print_info':
   mm/page_alloc.c:7911:27: warning: comparison between two arrays [-Warray-compare]
    7911 |                 if (start <= pos && pos < end && size > adj) \
         |                           ^~
   mm/page_alloc.c:7915:9: note: in expansion of macro 'adj_init_size'
    7915 |         adj_init_size(__init_begin, __init_end, init_data_size,
         |         ^~~~~~~~~~~~~
   mm/page_alloc.c:7911:27: note: use '&__init_begin[0] <= &_sinittext[0]' to compare the addresses
    7911 |                 if (start <= pos && pos < end && size > adj) \
         |                           ^~
   mm/page_alloc.c:7915:9: note: in expansion of macro 'adj_init_size'
    7915 |         adj_init_size(__init_begin, __init_end, init_data_size,
         |         ^~~~~~~~~~~~~
   mm/page_alloc.c:7911:41: warning: comparison between two arrays [-Warray-compare]
    7911 |                 if (start <= pos && pos < end && size > adj) \
         |                                         ^
   mm/page_alloc.c:7915:9: note: in expansion of macro 'adj_init_size'
    7915 |         adj_init_size(__init_begin, __init_end, init_data_size,
         |         ^~~~~~~~~~~~~
   mm/page_alloc.c:7911:41: note: use '&_sinittext[0] < &__init_end[0]' to compare the addresses
    7911 |                 if (start <= pos && pos < end && size > adj) \
         |                                         ^
   mm/page_alloc.c:7915:9: note: in expansion of macro 'adj_init_size'
    7915 |         adj_init_size(__init_begin, __init_end, init_data_size,
         |         ^~~~~~~~~~~~~
   mm/page_alloc.c:7911:27: warning: comparison between two arrays [-Warray-compare]
    7911 |                 if (start <= pos && pos < end && size > adj) \
         |                           ^~
   mm/page_alloc.c:7917:9: note: in expansion of macro 'adj_init_size'
    7917 |         adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
         |         ^~~~~~~~~~~~~
   mm/page_alloc.c:7911:27: note: use '&_stext[0] <= &_sinittext[0]' to compare the addresses
    7911 |                 if (start <= pos && pos < end && size > adj) \
         |                           ^~
   mm/page_alloc.c:7917:9: note: in expansion of macro 'adj_init_size'
    7917 |         adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
         |         ^~~~~~~~~~~~~
   mm/page_alloc.c:7911:41: warning: comparison between two arrays [-Warray-compare]
    7911 |                 if (start <= pos && pos < end && size > adj) \
         |                                         ^
   mm/page_alloc.c:7917:9: note: in expansion of macro 'adj_init_size'
    7917 |         adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
         |         ^~~~~~~~~~~~~
   mm/page_alloc.c:7911:41: note: use '&_sinittext[0] < &_etext[0]' to compare the addresses
    7911 |                 if (start <= pos && pos < end && size > adj) \
         |                                         ^
   mm/page_alloc.c:7917:9: note: in expansion of macro 'adj_init_size'
    7917 |         adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
         |         ^~~~~~~~~~~~~
   mm/page_alloc.c:7911:27: warning: comparison between two arrays [-Warray-compare]
    7911 |                 if (start <= pos && pos < end && size > adj) \
         |                           ^~
   mm/page_alloc.c:7918:9: note: in expansion of macro 'adj_init_size'
    7918 |         adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
         |         ^~~~~~~~~~~~~
   mm/page_alloc.c:7911:27: note: use '&_sdata[0] <= &__init_begin[0]' to compare the addresses
    7911 |                 if (start <= pos && pos < end && size > adj) \
         |                           ^~
   mm/page_alloc.c:7918:9: note: in expansion of macro 'adj_init_size'
    7918 |         adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
         |         ^~~~~~~~~~~~~
   mm/page_alloc.c:7911:41: warning: comparison between two arrays [-Warray-compare]
    7911 |                 if (start <= pos && pos < end && size > adj) \
         |                                         ^
   mm/page_alloc.c:7918:9: note: in expansion of macro 'adj_init_size'
    7918 |         adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
         |         ^~~~~~~~~~~~~
   mm/page_alloc.c:7911:41: note: use '&__init_begin[0] < &_edata[0]' to compare the addresses
    7911 |                 if (start <= pos && pos < end && size > adj) \
         |                                         ^
   mm/page_alloc.c:7918:9: note: in expansion of macro 'adj_init_size'
    7918 |         adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
         |         ^~~~~~~~~~~~~
   mm/page_alloc.c:7911:27: warning: comparison between two arrays [-Warray-compare]
    7911 |                 if (start <= pos && pos < end && size > adj) \
         |                           ^~
   mm/page_alloc.c:7919:9: note: in expansion of macro 'adj_init_size'
    7919 |         adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
         |         ^~~~~~~~~~~~~
   mm/page_alloc.c:7911:27: note: use '&_stext[0] <= &__start_rodata[0]' to compare the addresses
    7911 |                 if (start <= pos && pos < end && size > adj) \
         |                           ^~
   mm/page_alloc.c:7919:9: note: in expansion of macro 'adj_init_size'
    7919 |         adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
         |         ^~~~~~~~~~~~~
   mm/page_alloc.c:7911:41: warning: comparison between two arrays [-Warray-compare]
    7911 |                 if (start <= pos && pos < end && size > adj) \
         |                                         ^
   mm/page_alloc.c:7919:9: note: in expansion of macro 'adj_init_size'
    7919 |         adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
         |         ^~~~~~~~~~~~~
   mm/page_alloc.c:7911:41: note: use '&__start_rodata[0] < &_etext[0]' to compare the addresses
    7911 |                 if (start <= pos && pos < end && size > adj) \
         |                                         ^
   mm/page_alloc.c:7919:9: note: in expansion of macro 'adj_init_size'
    7919 |         adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
         |         ^~~~~~~~~~~~~
   mm/page_alloc.c:7911:27: warning: comparison between two arrays [-Warray-compare]
vim +/__drain_all_pages +3036 mm/page_alloc.c

  3025	
  3026	/*
  3027	 * The implementation of drain_all_pages(), exposing an extra parameter to
  3028	 * drain on all cpus.
  3029	 *
  3030	 * drain_all_pages() is optimized to only execute on cpus where pcplists are
  3031	 * not empty. The check for non-emptiness can however race with a free to
  3032	 * pcplist that has not yet increased the pcp->count from 0 to 1. Callers
  3033	 * that need the guarantee that every CPU has drained can disable the
  3034	 * optimizing racy check.
  3035	 */
...
3036	void __drain_all_pages(struct zone *zone, bool force_all_cpus)
  3037	{
  3038		int cpu;
  3039	
  3040		/*
  3041		 * Allocate in the BSS so we wont require allocation in
  3042		 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
  3043		 */
  3044		static cpumask_t cpus_with_pcps;
  3045	
  3046		/*
  3047		 * Make sure nobody triggers this path before mm_percpu_wq is fully
  3048		 * initialized.
  3049		 */
  3050		if (WARN_ON_ONCE(!mm_percpu_wq))
  3051			return;
  3052	
  3053		/*
  3054		 * Do not drain if one is already in progress unless it's specific to
  3055		 * a zone. Such callers are primarily CMA and memory hotplug and need
  3056		 * the drain to be complete when the call returns.
  3057		 */
  3058		if (unlikely(!mutex_trylock(&pcpu_drain_mutex))) {
  3059			if (!zone)
  3060				return;
  3061			mutex_lock(&pcpu_drain_mutex);
  3062		}
  3063	
  3064		/*
  3065		 * We don't care about racing with CPU hotplug event
  3066		 * as offline notification will cause the notified
  3067		 * cpu to drain that CPU pcps and on_each_cpu_mask
  3068		 * disables preemption as part of its processing
  3069		 */
  3070		for_each_online_cpu(cpu) {
  3071			struct per_cpu_pageset *pcp;
  3072			struct zone *z;
  3073			bool has_pcps = false;
  3074	
  3075			if (force_all_cpus) {
  3076				/*
  3077				 * The pcp.count check is racy, some callers need a
  3078				 * guarantee that no cpu is missed.
  3079				 */
  3080				has_pcps = true;
  3081			} else if (zone) {
  3082				pcp = per_cpu_ptr(zone->pageset, cpu);
  3083				if (pcp->pcp.count)
  3084					has_pcps = true;
  3085			} else {
  3086				for_each_populated_zone(z) {
  3087					pcp = per_cpu_ptr(z->pageset, cpu);
  3088					if (pcp->pcp.count) {
  3089						has_pcps = true;
  3090						break;
  3091					}
  3092				}
  3093			}
  3094	
  3095			if (has_pcps)
  3096				cpumask_set_cpu(cpu, &cpus_with_pcps);
  3097			else
  3098				cpumask_clear_cpu(cpu, &cpus_with_pcps);
  3099		}
  3100	
  3101		for_each_cpu(cpu, &cpus_with_pcps) {
  3102			struct pcpu_drain *drain = per_cpu_ptr(&pcpu_drain, cpu);
  3103	
  3104			drain->zone = zone;
  3105			INIT_WORK(&drain->work, drain_local_pages_wq);
  3106			queue_work_on(cpu, mm_percpu_wq, &drain->work);
  3107		}
  3108		for_each_cpu(cpu, &cpus_with_pcps)
  3109			flush_work(&per_cpu_ptr(&pcpu_drain, cpu)->work);
  3110	
  3111		mutex_unlock(&pcpu_drain_mutex);
  3112	}
  3113
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