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)

Mike Rapoport
2020-04-01T07:52:15Z

Hi,

On Wed, Apr 01, 2020 at 01:42:27PM +0800, Baoquan He wrote:
> 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.

alpha has NUMA marked as BROKEN for a long time now. I doubt anybody is
going to fix that.

> 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.

Well, microblaze probably copied it and forgot to remove and riscv might
get actual NUMA at some point.

> 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.

Replacing CONFIG_HAVE_MEMBLOCK_NODE_MAP with CONFIG_NUMA will work, but
this will not help cleaning up the whole node/zone initialization mess and
we'll be stuck with two implementations.

The overhead of enabling HAVE_MEMBLOCK_NODE_MAP is only for init time as
most architectures will anyway discard the entire memblock, so having it in
a UMA arch won't be a problem. The only exception is arm that uses
memblock for pfn_valid(), here we may also think about a solution to
compensate the addition of nid to the memblock structures.

We also may want to make all the movable_node and movable_core
functionality dependent on CONFIG_NUMA.

> > 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
> >
> >
>

--
Sincerely yours,
Mike.