Subject: Re: [PATCH RFC] mm: remove CONFIG_HAVE_MEMBLOCK_NODE_MAP (was: Re: [PATCH v3 0/5] mm: Enable CONFIG_NODES_SPAN_OTHER_NODES by default for NUMA)

From: Baoquan He <[email-masked]>
Date: Wed, 1 Apr 2020 13:42:27 +0800

On 04/01/20 at 12:56am, Mike Rapoport wrote:
> On Mon, Mar 30, 2020 at 11:58:43AM +0200, Michal Hocko wrote:
> > 
> > What would it take to make ia64 use HAVE_MEMBLOCK_NODE_MAP? I would
> > really love to see that thing go away. It is causing problems when
> > people try to use memblock api.
> 
> Well, it's a small patch in the end :)
> 
> Currently all NUMA architectures currently enable
> CONFIG_HAVE_MEMBLOCK_NODE_MAP and use free_area_init_nodes() to initialize
> nodes and zones structures.

I did some investigation, there are nine ARCHes having NUMA config. And
among them, alpha doesn't have HAVE_MEMBLOCK_NODE_MAP support. While the
interesting thing is there are two ARCHes which have
HAVE_MEMBLOCK_NODE_MAP config, but don't have NUMA config adding, they
are microblaze and riscv. Obviously it was not carefully considered to
add HAVE_MEMBLOCK_NODE_MAP config into riscv and microblaze.

arch/alpha/Kconfig:config NUMA
arch/arm64/Kconfig:config NUMA
arch/ia64/Kconfig:config NUMA
arch/mips/Kconfig:config NUMA
arch/powerpc/Kconfig:config NUMA
arch/s390/Kconfig:config NUMA
arch/sh/mm/Kconfig:config NUMA
arch/sparc/Kconfig:config NUMA
arch/x86/Kconfig:config NUMA

>From above information, we can remove HAVE_MEMBLOCK_NODE_MAP, and
replace it with CONFIG_NUMA. That sounds more sensible to store nid into
memblock when NUMA support is enabled.

> diff --git a/include/linux/memblock.h b/include/linux/memblock.h
> index 079d17d96410..9de81112447e 100644
> --- a/include/linux/memblock.h
> +++ b/include/linux/memblock.h
> @@ -50,9 +50,7 @@ struct memblock_region {
>  	phys_addr_t base;
>  	phys_addr_t size;
>  	enum memblock_flags flags;
> -#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
>  	int nid;
> -#endif

I didn't look into other change very carefully, but feel enabling
memblock node map for all ARCHes looks a little radical. After all, many
ARCHes even don't have NUMA support.

>  };
>  
>  /**
> @@ -215,7 +213,6 @@ static inline bool memblock_is_nomap(struct memblock_region *m)
>  	return m->flags & MEMBLOCK_NOMAP;
>  }
>  
> -#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
>  int memblock_search_pfn_nid(unsigned long pfn, unsigned long *start_pfn,
>  			    unsigned long  *end_pfn);
>  void __next_mem_pfn_range(int *idx, int nid, unsigned long *out_start_pfn,
> @@ -234,7 +231,6 @@ void __next_mem_pfn_range(int *idx, int nid, unsigned long *out_start_pfn,
>  #define for_each_mem_pfn_range(i, nid, p_start, p_end, p_nid)		\
>  	for (i = -1, __next_mem_pfn_range(&i, nid, p_start, p_end, p_nid); \
>  	     i >= 0; __next_mem_pfn_range(&i, nid, p_start, p_end, p_nid))
> -#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
>  
>  #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
>  void __next_mem_pfn_range_in_zone(u64 *idx, struct zone *zone,
> @@ -310,7 +306,6 @@ void __next_mem_pfn_range_in_zone(u64 *idx, struct zone *zone,
>  	for_each_mem_range_rev(i, &memblock.memory, &memblock.reserved,	\
>  			       nid, flags, p_start, p_end, p_nid)
>  
> -#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
>  int memblock_set_node(phys_addr_t base, phys_addr_t size,
>  		      struct memblock_type *type, int nid);
>  
> @@ -323,16 +318,6 @@ static inline int memblock_get_region_node(const struct memblock_region *r)
>  {
>  	return r->nid;
>  }
> -#else
> -static inline void memblock_set_region_node(struct memblock_region *r, int nid)
> -{
> -}
> -
> -static inline int memblock_get_region_node(const struct memblock_region *r)
> -{
> -	return 0;
> -}
> -#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
>  
>  /* Flags for memblock allocation APIs */
>  #define MEMBLOCK_ALLOC_ANYWHERE	(~(phys_addr_t)0)
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index c54fb96cb1e6..368a45d4696a 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2125,9 +2125,8 @@ static inline unsigned long get_num_physpages(void)
>  	return phys_pages;
>  }
>  
> -#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
>  /*
> - * With CONFIG_HAVE_MEMBLOCK_NODE_MAP set, an architecture may initialise its
> + * Using memblock node mappings, an architecture may initialise its
>   * zones, allocate the backing mem_map and account for memory holes in a more
>   * architecture independent manner. This is a substitute for creating the
>   * zone_sizes[] and zholes_size[] arrays and passing them to
> @@ -2148,9 +2147,6 @@ static inline unsigned long get_num_physpages(void)
>   * registered physical page range.  Similarly
>   * sparse_memory_present_with_active_regions() calls memory_present() for
>   * each range when SPARSEMEM is enabled.
> - *
> - * See mm/page_alloc.c for more information on each function exposed by
> - * CONFIG_HAVE_MEMBLOCK_NODE_MAP.
>   */
>  extern void free_area_init_nodes(unsigned long *max_zone_pfn);
>  unsigned long node_map_pfn_alignment(void);
> @@ -2165,22 +2161,12 @@ extern void free_bootmem_with_active_regions(int nid,
>  						unsigned long max_low_pfn);
>  extern void sparse_memory_present_with_active_regions(int nid);
>  
> -#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
>  
> -#if !defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) && \
> -    !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID)
> -static inline int __early_pfn_to_nid(unsigned long pfn,
> -					struct mminit_pfnnid_cache *state)
> -{
> -	return 0;
> -}
> -#else
>  /* please see mm/page_alloc.c */
>  extern int __meminit early_pfn_to_nid(unsigned long pfn);
>  /* there is a per-arch backend function. */
>  extern int __meminit __early_pfn_to_nid(unsigned long pfn,
>  					struct mminit_pfnnid_cache *state);
> -#endif
>  
>  extern void set_dma_reserve(unsigned long new_dma_reserve);
>  extern void memmap_init_zone(unsigned long, int, unsigned long, unsigned long,
> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
> index 462f6873905a..4422d1961d0e 100644
> --- a/include/linux/mmzone.h
> +++ b/include/linux/mmzone.h
> @@ -917,11 +917,7 @@ extern int movable_zone;
>  #ifdef CONFIG_HIGHMEM
>  static inline int zone_movable_is_highmem(void)
>  {
> -#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
>  	return movable_zone == ZONE_HIGHMEM;
> -#else
> -	return (ZONE_MOVABLE - 1) == ZONE_HIGHMEM;
> -#endif
>  }
>  #endif
>  
> @@ -1121,15 +1117,6 @@ static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist,
>  #include <asm/sparsemem.h>
>  #endif
>  
> -#if !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) && \
> -	!defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
> -static inline unsigned long early_pfn_to_nid(unsigned long pfn)
> -{
> -	BUILD_BUG_ON(IS_ENABLED(CONFIG_NUMA));
> -	return 0;
> -}
> -#endif
> -
>  #ifdef CONFIG_FLATMEM
>  #define pfn_to_nid(pfn)		(0)
>  #endif
> diff --git a/mm/memblock.c b/mm/memblock.c
> index eba94ee3de0b..819441133a21 100644
> --- a/mm/memblock.c
> +++ b/mm/memblock.c
> @@ -620,9 +620,7 @@ static int __init_memblock memblock_add_range(struct memblock_type *type,
>  		 * area, insert that portion.
>  		 */
>  		if (rbase > base) {
> -#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
>  			WARN_ON(nid != memblock_get_region_node(rgn));
> -#endif
>  			WARN_ON(flags != rgn->flags);
>  			nr_new++;
>  			if (insert)
> @@ -1197,7 +1195,6 @@ void __init_memblock __next_mem_range_rev(u64 *idx, int nid,
>  	*idx = ULLONG_MAX;
>  }
>  
> -#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
>  /*
>   * Common iterator interface used to define for_each_mem_pfn_range().
>   */
> @@ -1258,7 +1255,7 @@ int __init_memblock memblock_set_node(phys_addr_t base, phys_addr_t size,
>  	memblock_merge_regions(type);
>  	return 0;
>  }
> -#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
> +
>  #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
>  /**
>   * __next_mem_pfn_range_in_zone - iterator for for_each_*_range_in_zone()
> @@ -1797,7 +1794,6 @@ bool __init_memblock memblock_is_map_memory(phys_addr_t addr)
>  	return !memblock_is_nomap(&memblock.memory.regions[i]);
>  }
>  
> -#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
>  int __init_memblock memblock_search_pfn_nid(unsigned long pfn,
>  			 unsigned long *start_pfn, unsigned long *end_pfn)
>  {
> @@ -1812,7 +1808,6 @@ int __init_memblock memblock_search_pfn_nid(unsigned long pfn,
>  
>  	return type->regions[mid].nid;
>  }
> -#endif
>  
>  /**
>   * memblock_is_region_memory - check if a region is a subset of memory
> @@ -1903,11 +1898,9 @@ static void __init_memblock memblock_dump(struct memblock_type *type)
>  		size = rgn->size;
>  		end = base + size - 1;
>  		flags = rgn->flags;
> -#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
>  		if (memblock_get_region_node(rgn) != MAX_NUMNODES)
>  			snprintf(nid_buf, sizeof(nid_buf), " on node %d",
>  				 memblock_get_region_node(rgn));
> -#endif
>  		pr_info(" %s[%#x]\t[%pa-%pa], %pa bytes%s flags: %#x\n",
>  			type->name, idx, &base, &end, &size, nid_buf, flags);
>  	}
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 19389cdc16a5..dc8828b087bf 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -1366,11 +1366,7 @@ check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages,
>  
>  static int __init cmdline_parse_movable_node(char *p)
>  {
> -#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
>  	movable_node_enabled = true;
> -#else
> -	pr_warn("movable_node parameter depends on CONFIG_HAVE_MEMBLOCK_NODE_MAP to work properly\n");
> -#endif
>  	return 0;
>  }
>  early_param("movable_node", cmdline_parse_movable_node);
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 3c4eb750a199..84a69d6e7e61 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -335,7 +335,6 @@ static unsigned long nr_kernel_pages __initdata;
>  static unsigned long nr_all_pages __initdata;
>  static unsigned long dma_reserve __initdata;
>  
> -#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
>  static unsigned long arch_zone_lowest_possible_pfn[MAX_NR_ZONES] __initdata;
>  static unsigned long arch_zone_highest_possible_pfn[MAX_NR_ZONES] __initdata;
>  static unsigned long required_kernelcore __initdata;
> @@ -348,7 +347,6 @@ static bool mirrored_kernelcore __meminitdata;
>  /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
>  int movable_zone;
>  EXPORT_SYMBOL(movable_zone);
> -#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
>  
>  #if MAX_NUMNODES > 1
>  unsigned int nr_node_ids __read_mostly = MAX_NUMNODES;
> @@ -1447,9 +1445,6 @@ void __free_pages_core(struct page *page, unsigned int order)
>  	__free_pages(page, order);
>  }
>  
> -#if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
> -	defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
> -
>  static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata;
>  
>  int __meminit early_pfn_to_nid(unsigned long pfn)
> @@ -1465,7 +1460,6 @@ int __meminit early_pfn_to_nid(unsigned long pfn)
>  
>  	return nid;
>  }
> -#endif
>  
>  #ifdef CONFIG_NODES_SPAN_OTHER_NODES
>  /* Only safe to use early in boot when initialisation is single-threaded */
> @@ -5828,7 +5822,6 @@ void __ref build_all_zonelists(pg_data_t *pgdat)
>  static bool __meminit
>  overlap_memmap_init(unsigned long zone, unsigned long *pfn)
>  {
> -#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
>  	static struct memblock_region *r;
>  
>  	if (mirrored_kernelcore && zone == ZONE_MOVABLE) {
> @@ -5844,7 +5837,7 @@ overlap_memmap_init(unsigned long zone, unsigned long *pfn)
>  			return true;
>  		}
>  	}
> -#endif
> +
>  	return false;
>  }
>  
> @@ -6227,7 +6220,6 @@ void __meminit init_currently_empty_zone(struct zone *zone,
>  	zone->initialized = 1;
>  }
>  
> -#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
>  #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
>  
>  /*
> @@ -6503,8 +6495,7 @@ static unsigned long __init zone_absent_pages_in_node(int nid,
>  	return nr_absent;
>  }
>  
> -#else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
> -static inline unsigned long __init zone_spanned_pages_in_node(int nid,
> +static inline unsigned long __init compat_zone_spanned_pages_in_node(int nid,
>  					unsigned long zone_type,
>  					unsigned long node_start_pfn,
>  					unsigned long node_end_pfn,
> @@ -6523,7 +6514,7 @@ static inline unsigned long __init zone_spanned_pages_in_node(int nid,
>  	return zones_size[zone_type];
>  }
>  
> -static inline unsigned long __init zone_absent_pages_in_node(int nid,
> +static inline unsigned long __init compat_zone_absent_pages_in_node(int nid,
>  						unsigned long zone_type,
>  						unsigned long node_start_pfn,
>  						unsigned long node_end_pfn,
> @@ -6535,13 +6526,12 @@ static inline unsigned long __init zone_absent_pages_in_node(int nid,
>  	return zholes_size[zone_type];
>  }
>  
> -#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
> -
>  static void __init calculate_node_totalpages(struct pglist_data *pgdat,
>  						unsigned long node_start_pfn,
>  						unsigned long node_end_pfn,
>  						unsigned long *zones_size,
> -						unsigned long *zholes_size)
> +						unsigned long *zholes_size,
> +						bool compat)
>  {
>  	unsigned long realtotalpages = 0, totalpages = 0;
>  	enum zone_type i;
> @@ -6549,17 +6539,38 @@ static void __init calculate_node_totalpages(struct pglist_data *pgdat,
>  	for (i = 0; i < MAX_NR_ZONES; i++) {
>  		struct zone *zone = pgdat->node_zones + i;
>  		unsigned long zone_start_pfn, zone_end_pfn;
> +		unsigned long spanned, absent;
>  		unsigned long size, real_size;
>  
> -		size = zone_spanned_pages_in_node(pgdat->node_id, i,
> -						  node_start_pfn,
> -						  node_end_pfn,
> -						  &zone_start_pfn,
> -						  &zone_end_pfn,
> -						  zones_size);
> -		real_size = size - zone_absent_pages_in_node(pgdat->node_id, i,
> -						  node_start_pfn, node_end_pfn,
> -						  zholes_size);
> +		if (compat) {
> +			spanned = compat_zone_spanned_pages_in_node(
> +						pgdat->node_id, i,
> +						node_start_pfn,
> +						node_end_pfn,
> +						&zone_start_pfn,
> +						&zone_end_pfn,
> +						zones_size);
> +			absent = compat_zone_absent_pages_in_node(
> +						pgdat->node_id, i,
> +						node_start_pfn,
> +						node_end_pfn,
> +						zholes_size);
> +		} else {
> +			spanned = zone_spanned_pages_in_node(pgdat->node_id, i,
> +						node_start_pfn,
> +						node_end_pfn,
> +						&zone_start_pfn,
> +						&zone_end_pfn,
> +						zones_size);
> +			absent = zone_absent_pages_in_node(pgdat->node_id, i,
> +						node_start_pfn,
> +						node_end_pfn,
> +						zholes_size);
> +		}
> +
> +		size = spanned;
> +		real_size = size - absent;
> +
>  		if (size)
>  			zone->zone_start_pfn = zone_start_pfn;
>  		else
> @@ -6859,10 +6870,8 @@ static void __ref alloc_node_mem_map(struct pglist_data *pgdat)
>  	 */
>  	if (pgdat == NODE_DATA(0)) {
>  		mem_map = NODE_DATA(0)->node_mem_map;
> -#if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
>  		if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
>  			mem_map -= offset;
> -#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
>  	}
>  #endif
>  }
> @@ -6879,9 +6888,10 @@ static inline void pgdat_set_deferred_range(pg_data_t *pgdat)
>  static inline void pgdat_set_deferred_range(pg_data_t *pgdat) {}
>  #endif
>  
> -void __init free_area_init_node(int nid, unsigned long *zones_size,
> -				   unsigned long node_start_pfn,
> -				   unsigned long *zholes_size)
> +void __init __free_area_init_node(int nid, unsigned long *zones_size,
> +				  unsigned long node_start_pfn,
> +				  unsigned long *zholes_size,
> +				  bool compat)
>  {
>  	pg_data_t *pgdat = NODE_DATA(nid);
>  	unsigned long start_pfn = 0;
> @@ -6893,16 +6903,17 @@ void __init free_area_init_node(int nid, unsigned long *zones_size,
>  	pgdat->node_id = nid;
>  	pgdat->node_start_pfn = node_start_pfn;
>  	pgdat->per_cpu_nodestats = NULL;
> -#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
> -	get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
> -	pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
> -		(u64)start_pfn << PAGE_SHIFT,
> -		end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0);
> -#else
> -	start_pfn = node_start_pfn;
> -#endif
> +	if (!compat) {
> +		get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
> +		pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
> +			(u64)start_pfn << PAGE_SHIFT,
> +			end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0);
> +	} else {
> +		start_pfn = node_start_pfn;
> +	}
> +
>  	calculate_node_totalpages(pgdat, start_pfn, end_pfn,
> -				  zones_size, zholes_size);
> +				  zones_size, zholes_size, compat);
>  
>  	alloc_node_mem_map(pgdat);
>  	pgdat_set_deferred_range(pgdat);
> @@ -6910,6 +6921,14 @@ void __init free_area_init_node(int nid, unsigned long *zones_size,
>  	free_area_init_core(pgdat);
>  }
>  
> +void __init free_area_init_node(int nid, unsigned long *zones_size,
> +				unsigned long node_start_pfn,
> +				unsigned long *zholes_size)
> +{
> +	__free_area_init_node(nid, zones_size, node_start_pfn, zholes_size,
> +			      true);
> +}
> +
>  #if !defined(CONFIG_FLAT_NODE_MEM_MAP)
>  /*
>   * Initialize all valid struct pages in the range [spfn, epfn) and mark them
> @@ -6993,8 +7012,6 @@ static inline void __init init_unavailable_mem(void)
>  }
>  #endif /* !CONFIG_FLAT_NODE_MEM_MAP */
>  
> -#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
> -
>  #if MAX_NUMNODES > 1
>  /*
>   * Figure out the number of possible node ids.
> @@ -7423,8 +7440,8 @@ void __init free_area_init_nodes(unsigned long *max_zone_pfn)
>  	init_unavailable_mem();
>  	for_each_online_node(nid) {
>  		pg_data_t *pgdat = NODE_DATA(nid);
> -		free_area_init_node(nid, NULL,
> -				find_min_pfn_for_node(nid), NULL);
> +		__free_area_init_node(nid, NULL,
> +				      find_min_pfn_for_node(nid), NULL, false);
>  
>  		/* Any memory on that node */
>  		if (pgdat->node_present_pages)
> @@ -7489,8 +7506,6 @@ static int __init cmdline_parse_movablecore(char *p)
>  early_param("kernelcore", cmdline_parse_kernelcore);
>  early_param("movablecore", cmdline_parse_movablecore);
>  
> -#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
> -
>  void adjust_managed_page_count(struct page *page, long count)
>  {
>  	atomic_long_add(count, &page_zone(page)->managed_pages);
> -- 
> 2.25.1
> 
> 

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