diff options
Diffstat (limited to '')
| -rw-r--r-- | mm/memory_hotplug.c | 1699 |
1 files changed, 1094 insertions, 605 deletions
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 19389cdc16a5..fd40f7e9f176 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -21,7 +21,6 @@ #include <linux/memory.h> #include <linux/memremap.h> #include <linux/memory_hotplug.h> -#include <linux/highmem.h> #include <linux/vmalloc.h> #include <linux/ioport.h> #include <linux/delay.h> @@ -36,12 +35,99 @@ #include <linux/memblock.h> #include <linux/compaction.h> #include <linux/rmap.h> +#include <linux/module.h> #include <asm/tlbflush.h> #include "internal.h" #include "shuffle.h" +#ifdef CONFIG_MHP_MEMMAP_ON_MEMORY +/* + * memory_hotplug.memmap_on_memory parameter + */ +static bool memmap_on_memory __ro_after_init; +module_param(memmap_on_memory, bool, 0444); +MODULE_PARM_DESC(memmap_on_memory, "Enable memmap on memory for memory hotplug"); + +static inline bool mhp_memmap_on_memory(void) +{ + return memmap_on_memory; +} +#else +static inline bool mhp_memmap_on_memory(void) +{ + return false; +} +#endif + +enum { + ONLINE_POLICY_CONTIG_ZONES = 0, + ONLINE_POLICY_AUTO_MOVABLE, +}; + +static const char * const online_policy_to_str[] = { + [ONLINE_POLICY_CONTIG_ZONES] = "contig-zones", + [ONLINE_POLICY_AUTO_MOVABLE] = "auto-movable", +}; + +static int set_online_policy(const char *val, const struct kernel_param *kp) +{ + int ret = sysfs_match_string(online_policy_to_str, val); + + if (ret < 0) + return ret; + *((int *)kp->arg) = ret; + return 0; +} + +static int get_online_policy(char *buffer, const struct kernel_param *kp) +{ + return sprintf(buffer, "%s\n", online_policy_to_str[*((int *)kp->arg)]); +} + +/* + * memory_hotplug.online_policy: configure online behavior when onlining without + * specifying a zone (MMOP_ONLINE) + * + * "contig-zones": keep zone contiguous + * "auto-movable": online memory to ZONE_MOVABLE if the configuration + * (auto_movable_ratio, auto_movable_numa_aware) allows for it + */ +static int online_policy __read_mostly = ONLINE_POLICY_CONTIG_ZONES; +static const struct kernel_param_ops online_policy_ops = { + .set = set_online_policy, + .get = get_online_policy, +}; +module_param_cb(online_policy, &online_policy_ops, &online_policy, 0644); +MODULE_PARM_DESC(online_policy, + "Set the online policy (\"contig-zones\", \"auto-movable\") " + "Default: \"contig-zones\""); + +/* + * memory_hotplug.auto_movable_ratio: specify maximum MOVABLE:KERNEL ratio + * + * The ratio represent an upper limit and the kernel might decide to not + * online some memory to ZONE_MOVABLE -- e.g., because hotplugged KERNEL memory + * doesn't allow for more MOVABLE memory. + */ +static unsigned int auto_movable_ratio __read_mostly = 301; +module_param(auto_movable_ratio, uint, 0644); +MODULE_PARM_DESC(auto_movable_ratio, + "Set the maximum ratio of MOVABLE:KERNEL memory in the system " + "in percent for \"auto-movable\" online policy. Default: 301"); + +/* + * memory_hotplug.auto_movable_numa_aware: consider numa node stats + */ +#ifdef CONFIG_NUMA +static bool auto_movable_numa_aware __read_mostly = true; +module_param(auto_movable_numa_aware, bool, 0644); +MODULE_PARM_DESC(auto_movable_numa_aware, + "Consider numa node stats in addition to global stats in " + "\"auto-movable\" online policy. Default: true"); +#endif /* CONFIG_NUMA */ + /* * online_page_callback contains pointer to current page onlining function. * Initially it is generic_online_page(). If it is required it could be @@ -67,18 +153,17 @@ void put_online_mems(void) bool movable_node_enabled = false; #ifndef CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE -bool memhp_auto_online; +int mhp_default_online_type = MMOP_OFFLINE; #else -bool memhp_auto_online = true; +int mhp_default_online_type = MMOP_ONLINE; #endif -EXPORT_SYMBOL_GPL(memhp_auto_online); static int __init setup_memhp_default_state(char *str) { - if (!strcmp(str, "online")) - memhp_auto_online = true; - else if (!strcmp(str, "offline")) - memhp_auto_online = false; + const int online_type = mhp_online_type_from_str(str); + + if (online_type >= 0) + mhp_default_online_type = online_type; return 1; } @@ -99,13 +184,25 @@ void mem_hotplug_done(void) u64 max_mem_size = U64_MAX; /* add this memory to iomem resource */ -static struct resource *register_memory_resource(u64 start, u64 size) +static struct resource *register_memory_resource(u64 start, u64 size, + const char *resource_name) { struct resource *res; unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; - char *resource_name = "System RAM"; - if (start + size > max_mem_size) + if (strcmp(resource_name, "System RAM")) + flags |= IORESOURCE_SYSRAM_DRIVER_MANAGED; + + if (!mhp_range_allowed(start, size, true)) + return ERR_PTR(-E2BIG); + + /* + * Make sure value parsed from 'mem=' only restricts memory adding + * while booting, so that memory hotplug won't be impacted. Please + * refer to document of 'mem=' in kernel-parameters.txt for more + * details. + */ + if (start + size > max_mem_size && system_state < SYSTEM_RUNNING) return ERR_PTR(-E2BIG); /* @@ -132,125 +229,7 @@ static void release_memory_resource(struct resource *res) kfree(res); } -#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE -void get_page_bootmem(unsigned long info, struct page *page, - unsigned long type) -{ - page->freelist = (void *)type; - SetPagePrivate(page); - set_page_private(page, info); - page_ref_inc(page); -} - -void put_page_bootmem(struct page *page) -{ - unsigned long type; - - type = (unsigned long) page->freelist; - BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE || - type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE); - - if (page_ref_dec_return(page) == 1) { - page->freelist = NULL; - ClearPagePrivate(page); - set_page_private(page, 0); - INIT_LIST_HEAD(&page->lru); - free_reserved_page(page); - } -} - -#ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE -#ifndef CONFIG_SPARSEMEM_VMEMMAP -static void register_page_bootmem_info_section(unsigned long start_pfn) -{ - unsigned long mapsize, section_nr, i; - struct mem_section *ms; - struct page *page, *memmap; - struct mem_section_usage *usage; - - section_nr = pfn_to_section_nr(start_pfn); - ms = __nr_to_section(section_nr); - - /* Get section's memmap address */ - memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); - - /* - * Get page for the memmap's phys address - * XXX: need more consideration for sparse_vmemmap... - */ - page = virt_to_page(memmap); - mapsize = sizeof(struct page) * PAGES_PER_SECTION; - mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT; - - /* remember memmap's page */ - for (i = 0; i < mapsize; i++, page++) - get_page_bootmem(section_nr, page, SECTION_INFO); - - usage = ms->usage; - page = virt_to_page(usage); - - mapsize = PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT; - - for (i = 0; i < mapsize; i++, page++) - get_page_bootmem(section_nr, page, MIX_SECTION_INFO); - -} -#else /* CONFIG_SPARSEMEM_VMEMMAP */ -static void register_page_bootmem_info_section(unsigned long start_pfn) -{ - unsigned long mapsize, section_nr, i; - struct mem_section *ms; - struct page *page, *memmap; - struct mem_section_usage *usage; - - section_nr = pfn_to_section_nr(start_pfn); - ms = __nr_to_section(section_nr); - - memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); - - register_page_bootmem_memmap(section_nr, memmap, PAGES_PER_SECTION); - - usage = ms->usage; - page = virt_to_page(usage); - - mapsize = PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT; - - for (i = 0; i < mapsize; i++, page++) - get_page_bootmem(section_nr, page, MIX_SECTION_INFO); -} -#endif /* !CONFIG_SPARSEMEM_VMEMMAP */ - -void __init register_page_bootmem_info_node(struct pglist_data *pgdat) -{ - unsigned long i, pfn, end_pfn, nr_pages; - int node = pgdat->node_id; - struct page *page; - - nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT; - page = virt_to_page(pgdat); - - for (i = 0; i < nr_pages; i++, page++) - get_page_bootmem(node, page, NODE_INFO); - - pfn = pgdat->node_start_pfn; - end_pfn = pgdat_end_pfn(pgdat); - - /* register section info */ - for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) { - /* - * Some platforms can assign the same pfn to multiple nodes - on - * node0 as well as nodeN. To avoid registering a pfn against - * multiple nodes we check that this pfn does not already - * reside in some other nodes. - */ - if (pfn_valid(pfn) && (early_pfn_to_nid(pfn) == node)) - register_page_bootmem_info_section(pfn); - } -} -#endif /* CONFIG_HAVE_BOOTMEM_INFO_NODE */ - -static int check_pfn_span(unsigned long pfn, unsigned long nr_pages, - const char *reason) +static int check_pfn_span(unsigned long pfn, unsigned long nr_pages) { /* * Disallow all operations smaller than a sub-section and only @@ -267,47 +246,71 @@ static int check_pfn_span(unsigned long pfn, unsigned long nr_pages, min_align = PAGES_PER_SUBSECTION; else min_align = PAGES_PER_SECTION; - if (!IS_ALIGNED(pfn, min_align) - || !IS_ALIGNED(nr_pages, min_align)) { - WARN(1, "Misaligned __%s_pages start: %#lx end: #%lx\n", - reason, pfn, pfn + nr_pages - 1); + if (!IS_ALIGNED(pfn | nr_pages, min_align)) return -EINVAL; - } return 0; } -static int check_hotplug_memory_addressable(unsigned long pfn, - unsigned long nr_pages) +/* + * Return page for the valid pfn only if the page is online. All pfn + * walkers which rely on the fully initialized page->flags and others + * should use this rather than pfn_valid && pfn_to_page + */ +struct page *pfn_to_online_page(unsigned long pfn) { - const u64 max_addr = PFN_PHYS(pfn + nr_pages) - 1; + unsigned long nr = pfn_to_section_nr(pfn); + struct dev_pagemap *pgmap; + struct mem_section *ms; - if (max_addr >> MAX_PHYSMEM_BITS) { - const u64 max_allowed = (1ull << (MAX_PHYSMEM_BITS + 1)) - 1; - WARN(1, - "Hotplugged memory exceeds maximum addressable address, range=%#llx-%#llx, maximum=%#llx\n", - (u64)PFN_PHYS(pfn), max_addr, max_allowed); - return -E2BIG; - } + if (nr >= NR_MEM_SECTIONS) + return NULL; - return 0; + ms = __nr_to_section(nr); + if (!online_section(ms)) + return NULL; + + /* + * Save some code text when online_section() + + * pfn_section_valid() are sufficient. + */ + if (IS_ENABLED(CONFIG_HAVE_ARCH_PFN_VALID) && !pfn_valid(pfn)) + return NULL; + + if (!pfn_section_valid(ms, pfn)) + return NULL; + + if (!online_device_section(ms)) + return pfn_to_page(pfn); + + /* + * Slowpath: when ZONE_DEVICE collides with + * ZONE_{NORMAL,MOVABLE} within the same section some pfns in + * the section may be 'offline' but 'valid'. Only + * get_dev_pagemap() can determine sub-section online status. + */ + pgmap = get_dev_pagemap(pfn, NULL); + put_dev_pagemap(pgmap); + + /* The presence of a pgmap indicates ZONE_DEVICE offline pfn */ + if (pgmap) + return NULL; + + return pfn_to_page(pfn); } +EXPORT_SYMBOL_GPL(pfn_to_online_page); -/* - * Reasonably generic function for adding memory. It is - * expected that archs that support memory hotplug will - * call this function after deciding the zone to which to - * add the new pages. - */ int __ref __add_pages(int nid, unsigned long pfn, unsigned long nr_pages, - struct mhp_restrictions *restrictions) + struct mhp_params *params) { + const unsigned long end_pfn = pfn + nr_pages; + unsigned long cur_nr_pages; int err; - unsigned long nr, start_sec, end_sec; - struct vmem_altmap *altmap = restrictions->altmap; + struct vmem_altmap *altmap = params->altmap; + + if (WARN_ON_ONCE(!pgprot_val(params->pgprot))) + return -EINVAL; - err = check_hotplug_memory_addressable(pfn, nr_pages); - if (err) - return err; + VM_BUG_ON(!mhp_range_allowed(PFN_PHYS(pfn), nr_pages * PAGE_SIZE, false)); if (altmap) { /* @@ -321,22 +324,19 @@ int __ref __add_pages(int nid, unsigned long pfn, unsigned long nr_pages, altmap->alloc = 0; } - err = check_pfn_span(pfn, nr_pages, "add"); - if (err) - return err; - - start_sec = pfn_to_section_nr(pfn); - end_sec = pfn_to_section_nr(pfn + nr_pages - 1); - for (nr = start_sec; nr <= end_sec; nr++) { - unsigned long pfns; + if (check_pfn_span(pfn, nr_pages)) { + WARN(1, "Misaligned %s start: %#lx end: #%lx\n", __func__, pfn, pfn + nr_pages - 1); + return -EINVAL; + } - pfns = min(nr_pages, PAGES_PER_SECTION - - (pfn & ~PAGE_SECTION_MASK)); - err = sparse_add_section(nid, pfn, pfns, altmap); + for (; pfn < end_pfn; pfn += cur_nr_pages) { + /* Select all remaining pages up to the next section boundary */ + cur_nr_pages = min(end_pfn - pfn, + SECTION_ALIGN_UP(pfn + 1) - pfn); + err = sparse_add_section(nid, pfn, cur_nr_pages, altmap, + params->pgmap); if (err) break; - pfn += pfns; - nr_pages -= pfns; cond_resched(); } vmemmap_populate_print_last(); @@ -395,7 +395,6 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, unsigned long pfn; int nid = zone_to_nid(zone); - zone_span_writelock(zone); if (zone->zone_start_pfn == start_pfn) { /* * If the section is smallest section in the zone, it need @@ -428,7 +427,6 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, zone->spanned_pages = 0; } } - zone_span_writeunlock(zone); } static void update_pgdat_span(struct pglist_data *pgdat) @@ -438,20 +436,19 @@ static void update_pgdat_span(struct pglist_data *pgdat) for (zone = pgdat->node_zones; zone < pgdat->node_zones + MAX_NR_ZONES; zone++) { - unsigned long zone_end_pfn = zone->zone_start_pfn + - zone->spanned_pages; + unsigned long end_pfn = zone_end_pfn(zone); /* No need to lock the zones, they can't change. */ if (!zone->spanned_pages) continue; if (!node_end_pfn) { node_start_pfn = zone->zone_start_pfn; - node_end_pfn = zone_end_pfn; + node_end_pfn = end_pfn; continue; } - if (zone_end_pfn > node_end_pfn) - node_end_pfn = zone_end_pfn; + if (end_pfn > node_end_pfn) + node_end_pfn = end_pfn; if (zone->zone_start_pfn < node_start_pfn) node_start_pfn = zone->zone_start_pfn; } @@ -464,28 +461,33 @@ void __ref remove_pfn_range_from_zone(struct zone *zone, unsigned long start_pfn, unsigned long nr_pages) { + const unsigned long end_pfn = start_pfn + nr_pages; struct pglist_data *pgdat = zone->zone_pgdat; - unsigned long flags; + unsigned long pfn, cur_nr_pages; /* Poison struct pages because they are now uninitialized again. */ - page_init_poison(pfn_to_page(start_pfn), sizeof(struct page) * nr_pages); + for (pfn = start_pfn; pfn < end_pfn; pfn += cur_nr_pages) { + cond_resched(); + + /* Select all remaining pages up to the next section boundary */ + cur_nr_pages = + min(end_pfn - pfn, SECTION_ALIGN_UP(pfn + 1) - pfn); + page_init_poison(pfn_to_page(pfn), + sizeof(struct page) * cur_nr_pages); + } -#ifdef CONFIG_ZONE_DEVICE /* * Zone shrinking code cannot properly deal with ZONE_DEVICE. So * we will not try to shrink the zones - which is okay as * set_zone_contiguous() cannot deal with ZONE_DEVICE either way. */ - if (zone_idx(zone) == ZONE_DEVICE) + if (zone_is_zone_device(zone)) return; -#endif clear_zone_contiguous(zone); - pgdat_resize_lock(zone->zone_pgdat, &flags); shrink_zone_span(zone, start_pfn, start_pfn + nr_pages); update_pgdat_span(pgdat); - pgdat_resize_unlock(zone->zone_pgdat, &flags); set_zone_contiguous(zone); } @@ -494,7 +496,7 @@ static void __remove_section(unsigned long pfn, unsigned long nr_pages, unsigned long map_offset, struct vmem_altmap *altmap) { - struct mem_section *ms = __nr_to_section(pfn_to_section_nr(pfn)); + struct mem_section *ms = __pfn_to_section(pfn); if (WARN_ON_ONCE(!valid_section(ms))) return; @@ -522,13 +524,16 @@ void __remove_pages(unsigned long pfn, unsigned long nr_pages, map_offset = vmem_altmap_offset(altmap); - if (check_pfn_span(pfn, nr_pages, "remove")) + if (check_pfn_span(pfn, nr_pages)) { + WARN(1, "Misaligned %s start: %#lx end: #%lx\n", __func__, pfn, pfn + nr_pages - 1); return; + } for (; pfn < end_pfn; pfn += cur_nr_pages) { cond_resched(); /* Select all remaining pages up to the next section boundary */ - cur_nr_pages = min(end_pfn - pfn, -(pfn | PAGE_SECTION_MASK)); + cur_nr_pages = min(end_pfn - pfn, + SECTION_ALIGN_UP(pfn + 1) - pfn); __remove_section(pfn, cur_nr_pages, map_offset, altmap); map_offset = 0; } @@ -579,42 +584,35 @@ void generic_online_page(struct page *page, unsigned int order) * so we should map it first. This is better than introducing a special * case in page freeing fast path. */ - if (debug_pagealloc_enabled_static()) - kernel_map_pages(page, 1 << order, 1); + debug_pagealloc_map_pages(page, 1 << order); __free_pages_core(page, order); totalram_pages_add(1UL << order); -#ifdef CONFIG_HIGHMEM - if (PageHighMem(page)) - totalhigh_pages_add(1UL << order); -#endif } EXPORT_SYMBOL_GPL(generic_online_page); -static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages, - void *arg) +static void online_pages_range(unsigned long start_pfn, unsigned long nr_pages) { const unsigned long end_pfn = start_pfn + nr_pages; unsigned long pfn; - int order; /* - * Online the pages. The callback might decide to keep some pages - * PG_reserved (to add them to the buddy later), but we still account - * them as being online/belonging to this zone ("present"). + * Online the pages in MAX_ORDER - 1 aligned chunks. The callback might + * decide to not expose all pages to the buddy (e.g., expose them + * later). We account all pages as being online and belonging to this + * zone ("present"). + * When using memmap_on_memory, the range might not be aligned to + * MAX_ORDER_NR_PAGES - 1, but pageblock aligned. __ffs() will detect + * this and the first chunk to online will be pageblock_nr_pages. */ - for (pfn = start_pfn; pfn < end_pfn; pfn += 1ul << order) { - order = min(MAX_ORDER - 1, get_order(PFN_PHYS(end_pfn - pfn))); - /* __free_pages_core() wants pfns to be aligned to the order */ - if (WARN_ON_ONCE(!IS_ALIGNED(pfn, 1ul << order))) - order = 0; + for (pfn = start_pfn; pfn < end_pfn;) { + int order = min(MAX_ORDER - 1UL, __ffs(pfn)); + (*online_page_callback)(pfn_to_page(pfn), order); + pfn += (1UL << order); } /* mark all involved sections as online */ online_mem_sections(start_pfn, end_pfn); - - *(unsigned long *)arg += nr_pages; - return 0; } /* check which state of node_states will be changed when online memory */ @@ -625,16 +623,11 @@ static void node_states_check_changes_online(unsigned long nr_pages, arg->status_change_nid = NUMA_NO_NODE; arg->status_change_nid_normal = NUMA_NO_NODE; - arg->status_change_nid_high = NUMA_NO_NODE; if (!node_state(nid, N_MEMORY)) arg->status_change_nid = nid; if (zone_idx(zone) <= ZONE_NORMAL && !node_state(nid, N_NORMAL_MEMORY)) arg->status_change_nid_normal = nid; -#ifdef CONFIG_HIGHMEM - if (zone_idx(zone) <= ZONE_HIGHMEM && !node_state(nid, N_HIGH_MEMORY)) - arg->status_change_nid_high = nid; -#endif } static void node_states_set_node(int node, struct memory_notify *arg) @@ -642,9 +635,6 @@ static void node_states_set_node(int node, struct memory_notify *arg) if (arg->status_change_nid_normal >= 0) node_set_state(node, N_NORMAL_MEMORY); - if (arg->status_change_nid_high >= 0) - node_set_state(node, N_HIGH_MEMORY); - if (arg->status_change_nid >= 0) node_set_state(node, N_MEMORY); } @@ -671,29 +661,55 @@ static void __meminit resize_pgdat_range(struct pglist_data *pgdat, unsigned lon pgdat->node_spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - pgdat->node_start_pfn; } + +#ifdef CONFIG_ZONE_DEVICE +static void section_taint_zone_device(unsigned long pfn) +{ + struct mem_section *ms = __pfn_to_section(pfn); + + ms->section_mem_map |= SECTION_TAINT_ZONE_DEVICE; +} +#else +static inline void section_taint_zone_device(unsigned long pfn) +{ +} +#endif + /* * Associate the pfn range with the given zone, initializing the memmaps * and resizing the pgdat/zone data to span the added pages. After this * call, all affected pages are PG_reserved. + * + * All aligned pageblocks are initialized to the specified migratetype + * (usually MIGRATE_MOVABLE). Besides setting the migratetype, no related + * zone stats (e.g., nr_isolate_pageblock) are touched. */ void __ref move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn, - unsigned long nr_pages, struct vmem_altmap *altmap) + unsigned long nr_pages, + struct vmem_altmap *altmap, int migratetype) { struct pglist_data *pgdat = zone->zone_pgdat; int nid = pgdat->node_id; - unsigned long flags; clear_zone_contiguous(zone); - /* TODO Huh pgdat is irqsave while zone is not. It used to be like that before */ - pgdat_resize_lock(pgdat, &flags); - zone_span_writelock(zone); if (zone_is_empty(zone)) init_currently_empty_zone(zone, start_pfn, nr_pages); resize_zone_range(zone, start_pfn, nr_pages); - zone_span_writeunlock(zone); resize_pgdat_range(pgdat, start_pfn, nr_pages); - pgdat_resize_unlock(pgdat, &flags); + + /* + * Subsection population requires care in pfn_to_online_page(). + * Set the taint to enable the slow path detection of + * ZONE_DEVICE pages in an otherwise ZONE_{NORMAL,MOVABLE} + * section. + */ + if (zone_is_zone_device(zone)) { + if (!IS_ALIGNED(start_pfn, PAGES_PER_SECTION)) + section_taint_zone_device(start_pfn); + if (!IS_ALIGNED(start_pfn + nr_pages, PAGES_PER_SECTION)) + section_taint_zone_device(start_pfn + nr_pages); + } /* * TODO now we have a visible range of pages which are not associated @@ -701,12 +717,115 @@ void __ref move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn, * expects the zone spans the pfn range. All the pages in the range * are reserved so nobody should be touching them so we should be safe */ - memmap_init_zone(nr_pages, nid, zone_idx(zone), start_pfn, - MEMMAP_HOTPLUG, altmap); + memmap_init_range(nr_pages, nid, zone_idx(zone), start_pfn, 0, + MEMINIT_HOTPLUG, altmap, migratetype); set_zone_contiguous(zone); } +struct auto_movable_stats { + unsigned long kernel_early_pages; + unsigned long movable_pages; +}; + +static void auto_movable_stats_account_zone(struct auto_movable_stats *stats, + struct zone *zone) +{ + if (zone_idx(zone) == ZONE_MOVABLE) { + stats->movable_pages += zone->present_pages; + } else { + stats->kernel_early_pages += zone->present_early_pages; +#ifdef CONFIG_CMA + /* + * CMA pages (never on hotplugged memory) behave like + * ZONE_MOVABLE. + */ + stats->movable_pages += zone->cma_pages; + stats->kernel_early_pages -= zone->cma_pages; +#endif /* CONFIG_CMA */ + } +} +struct auto_movable_group_stats { + unsigned long movable_pages; + unsigned long req_kernel_early_pages; +}; + +static int auto_movable_stats_account_group(struct memory_group *group, + void *arg) +{ + const int ratio = READ_ONCE(auto_movable_ratio); + struct auto_movable_group_stats *stats = arg; + long pages; + + /* + * We don't support modifying the config while the auto-movable online + * policy is already enabled. Just avoid the division by zero below. + */ + if (!ratio) + return 0; + + /* + * Calculate how many early kernel pages this group requires to + * satisfy the configured zone ratio. + */ + pages = group->present_movable_pages * 100 / ratio; + pages -= group->present_kernel_pages; + + if (pages > 0) + stats->req_kernel_early_pages += pages; + stats->movable_pages += group->present_movable_pages; + return 0; +} + +static bool auto_movable_can_online_movable(int nid, struct memory_group *group, + unsigned long nr_pages) +{ + unsigned long kernel_early_pages, movable_pages; + struct auto_movable_group_stats group_stats = {}; + struct auto_movable_stats stats = {}; + pg_data_t *pgdat = NODE_DATA(nid); + struct zone *zone; + int i; + + /* Walk all relevant zones and collect MOVABLE vs. KERNEL stats. */ + if (nid == NUMA_NO_NODE) { + /* TODO: cache values */ + for_each_populated_zone(zone) + auto_movable_stats_account_zone(&stats, zone); + } else { + for (i = 0; i < MAX_NR_ZONES; i++) { + zone = pgdat->node_zones + i; + if (populated_zone(zone)) + auto_movable_stats_account_zone(&stats, zone); + } + } + + kernel_early_pages = stats.kernel_early_pages; + movable_pages = stats.movable_pages; + + /* + * Kernel memory inside dynamic memory group allows for more MOVABLE + * memory within the same group. Remove the effect of all but the + * current group from the stats. + */ + walk_dynamic_memory_groups(nid, auto_movable_stats_account_group, + group, &group_stats); + if (kernel_early_pages <= group_stats.req_kernel_early_pages) + return false; + kernel_early_pages -= group_stats.req_kernel_early_pages; + movable_pages -= group_stats.movable_pages; + + if (group && group->is_dynamic) + kernel_early_pages += group->present_kernel_pages; + + /* + * Test if we could online the given number of pages to ZONE_MOVABLE + * and still stay in the configured ratio. + */ + movable_pages += nr_pages; + return movable_pages <= (auto_movable_ratio * kernel_early_pages) / 100; +} + /* * Returns a default kernel memory zone for the given pfn range. * If no kernel zone covers this pfn range it will automatically go @@ -718,7 +837,7 @@ static struct zone *default_kernel_zone_for_pfn(int nid, unsigned long start_pfn struct pglist_data *pgdat = NODE_DATA(nid); int zid; - for (zid = 0; zid <= ZONE_NORMAL; zid++) { + for (zid = 0; zid < ZONE_NORMAL; zid++) { struct zone *zone = &pgdat->node_zones[zid]; if (zone_intersects(zone, start_pfn, nr_pages)) @@ -728,6 +847,117 @@ static struct zone *default_kernel_zone_for_pfn(int nid, unsigned long start_pfn return &pgdat->node_zones[ZONE_NORMAL]; } +/* + * Determine to which zone to online memory dynamically based on user + * configuration and system stats. We care about the following ratio: + * + * MOVABLE : KERNEL + * + * Whereby MOVABLE is memory in ZONE_MOVABLE and KERNEL is memory in + * one of the kernel zones. CMA pages inside one of the kernel zones really + * behaves like ZONE_MOVABLE, so we treat them accordingly. + * + * We don't allow for hotplugged memory in a KERNEL zone to increase the + * amount of MOVABLE memory we can have, so we end up with: + * + * MOVABLE : KERNEL_EARLY + * + * Whereby KERNEL_EARLY is memory in one of the kernel zones, available sinze + * boot. We base our calculation on KERNEL_EARLY internally, because: + * + * a) Hotplugged memory in one of the kernel zones can sometimes still get + * hotunplugged, especially when hot(un)plugging individual memory blocks. + * There is no coordination across memory devices, therefore "automatic" + * hotunplugging, as implemented in hypervisors, could result in zone + * imbalances. + * b) Early/boot memory in one of the kernel zones can usually not get + * hotunplugged again (e.g., no firmware interface to unplug, fragmented + * with unmovable allocations). While there are corner cases where it might + * still work, it is barely relevant in practice. + * + * Exceptions are dynamic memory groups, which allow for more MOVABLE + * memory within the same memory group -- because in that case, there is + * coordination within the single memory device managed by a single driver. + * + * We rely on "present pages" instead of "managed pages", as the latter is + * highly unreliable and dynamic in virtualized environments, and does not + * consider boot time allocations. For example, memory ballooning adjusts the + * managed pages when inflating/deflating the balloon, and balloon compaction + * can even migrate inflated pages between zones. + * + * Using "present pages" is better but some things to keep in mind are: + * + * a) Some memblock allocations, such as for the crashkernel area, are + * effectively unused by the kernel, yet they account to "present pages". + * Fortunately, these allocations are comparatively small in relevant setups + * (e.g., fraction of system memory). + * b) Some hotplugged memory blocks in virtualized environments, esecially + * hotplugged by virtio-mem, look like they are completely present, however, + * only parts of the memory block are actually currently usable. + * "present pages" is an upper limit that can get reached at runtime. As + * we base our calculations on KERNEL_EARLY, this is not an issue. + */ +static struct zone *auto_movable_zone_for_pfn(int nid, + struct memory_group *group, + unsigned long pfn, + unsigned long nr_pages) +{ + unsigned long online_pages = 0, max_pages, end_pfn; + struct page *page; + + if (!auto_movable_ratio) + goto kernel_zone; + + if (group && !group->is_dynamic) { + max_pages = group->s.max_pages; + online_pages = group->present_movable_pages; + + /* If anything is !MOVABLE online the rest !MOVABLE. */ + if (group->present_kernel_pages) + goto kernel_zone; + } else if (!group || group->d.unit_pages == nr_pages) { + max_pages = nr_pages; + } else { + max_pages = group->d.unit_pages; + /* + * Take a look at all online sections in the current unit. + * We can safely assume that all pages within a section belong + * to the same zone, because dynamic memory groups only deal + * with hotplugged memory. + */ + pfn = ALIGN_DOWN(pfn, group->d.unit_pages); + end_pfn = pfn + group->d.unit_pages; + for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) { + page = pfn_to_online_page(pfn); + if (!page) + continue; + /* If anything is !MOVABLE online the rest !MOVABLE. */ + if (!is_zone_movable_page(page)) + goto kernel_zone; + online_pages += PAGES_PER_SECTION; + } + } + + /* + * Online MOVABLE if we could *currently* online all remaining parts + * MOVABLE. We expect to (add+) online them immediately next, so if + * nobody interferes, all will be MOVABLE if possible. + */ + nr_pages = max_pages - online_pages; + if (!auto_movable_can_online_movable(NUMA_NO_NODE, group, nr_pages)) + goto kernel_zone; + +#ifdef CONFIG_NUMA + if (auto_movable_numa_aware && + !auto_movable_can_online_movable(nid, group, nr_pages)) + goto kernel_zone; +#endif /* CONFIG_NUMA */ + + return &NODE_DATA(nid)->node_zones[ZONE_MOVABLE]; +kernel_zone: + return default_kernel_zone_for_pfn(nid, pfn, nr_pages); +} + static inline struct zone *default_zone_for_pfn(int nid, unsigned long start_pfn, unsigned long nr_pages) { @@ -752,7 +982,8 @@ static inline struct zone *default_zone_for_pfn(int nid, unsigned long start_pfn return movable_node_enabled ? movable_zone : kernel_zone; } -struct zone * zone_for_pfn_range(int online_type, int nid, unsigned start_pfn, +struct zone *zone_for_pfn_range(int online_type, int nid, + struct memory_group *group, unsigned long start_pfn, unsigned long nr_pages) { if (online_type == MMOP_ONLINE_KERNEL) @@ -761,24 +992,107 @@ struct zone * zone_for_pfn_range(int online_type, int nid, unsigned start_pfn, if (online_type == MMOP_ONLINE_MOVABLE) return &NODE_DATA(nid)->node_zones[ZONE_MOVABLE]; + if (online_policy == ONLINE_POLICY_AUTO_MOVABLE) + return auto_movable_zone_for_pfn(nid, group, start_pfn, nr_pages); + return default_zone_for_pfn(nid, start_pfn, nr_pages); } +/* + * This function should only be called by memory_block_{online,offline}, + * and {online,offline}_pages. + */ +void adjust_present_page_count(struct page *page, struct memory_group *group, + long nr_pages) +{ + struct zone *zone = page_zone(page); + const bool movable = zone_idx(zone) == ZONE_MOVABLE; + + /* + * We only support onlining/offlining/adding/removing of complete + * memory blocks; therefore, either all is either early or hotplugged. + */ + if (early_section(__pfn_to_section(page_to_pfn(page)))) + zone->present_early_pages += nr_pages; + zone->present_pages += nr_pages; + zone->zone_pgdat->node_present_pages += nr_pages; + + if (group && movable) + group->present_movable_pages += nr_pages; + else if (group && !movable) + group->present_kernel_pages += nr_pages; +} + +int mhp_init_memmap_on_memory(unsigned long pfn, unsigned long nr_pages, + struct zone *zone) +{ + unsigned long end_pfn = pfn + nr_pages; + int ret, i; + + ret = kasan_add_zero_shadow(__va(PFN_PHYS(pfn)), PFN_PHYS(nr_pages)); + if (ret) + return ret; + + move_pfn_range_to_zone(zone, pfn, nr_pages, NULL, MIGRATE_UNMOVABLE); + + for (i = 0; i < nr_pages; i++) + SetPageVmemmapSelfHosted(pfn_to_page(pfn + i)); + + /* + * It might be that the vmemmap_pages fully span sections. If that is + * the case, mark those sections online here as otherwise they will be + * left offline. + */ + if (nr_pages >= PAGES_PER_SECTION) + online_mem_sections(pfn, ALIGN_DOWN(end_pfn, PAGES_PER_SECTION)); + + return ret; +} + +void mhp_deinit_memmap_on_memory(unsigned long pfn, unsigned long nr_pages) +{ + unsigned long end_pfn = pfn + nr_pages; + + /* + * It might be that the vmemmap_pages fully span sections. If that is + * the case, mark those sections offline here as otherwise they will be + * left online. + */ + if (nr_pages >= PAGES_PER_SECTION) + offline_mem_sections(pfn, ALIGN_DOWN(end_pfn, PAGES_PER_SECTION)); + + /* + * The pages associated with this vmemmap have been offlined, so + * we can reset its state here. + */ + remove_pfn_range_from_zone(page_zone(pfn_to_page(pfn)), pfn, nr_pages); + kasan_remove_zero_shadow(__va(PFN_PHYS(pfn)), PFN_PHYS(nr_pages)); +} + int __ref online_pages(unsigned long pfn, unsigned long nr_pages, - int online_type, int nid) + struct zone *zone, struct memory_group *group) { unsigned long flags; - unsigned long onlined_pages = 0; - struct zone *zone; int need_zonelists_rebuild = 0; + const int nid = zone_to_nid(zone); int ret; struct memory_notify arg; + /* + * {on,off}lining is constrained to full memory sections (or more + * precisely to memory blocks from the user space POV). + * memmap_on_memory is an exception because it reserves initial part + * of the physical memory space for vmemmaps. That space is pageblock + * aligned. + */ + if (WARN_ON_ONCE(!nr_pages || !pageblock_aligned(pfn) || + !IS_ALIGNED(pfn + nr_pages, PAGES_PER_SECTION))) + return -EINVAL; + mem_hotplug_begin(); /* associate pfn range with the zone */ - zone = zone_for_pfn_range(online_type, nid, pfn, nr_pages); - move_pfn_range_to_zone(zone, pfn, nr_pages, NULL); + move_pfn_range_to_zone(zone, pfn, nr_pages, NULL, MIGRATE_ISOLATE); arg.start_pfn = pfn; arg.nr_pages = nr_pages; @@ -790,6 +1104,14 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, goto failed_addition; /* + * Fixup the number of isolated pageblocks before marking the sections + * onlining, such that undo_isolate_page_range() works correctly. + */ + spin_lock_irqsave(&zone->lock, flags); + zone->nr_isolate_pageblock += nr_pages / pageblock_nr_pages; + spin_unlock_irqrestore(&zone->lock, flags); + + /* * If this zone is not populated, then it is not in zonelist. * This means the page allocator ignores this zone. * So, zonelist must be updated after online. @@ -799,36 +1121,30 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, setup_zone_pageset(zone); } - ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages, - online_pages_range); - if (ret) { - /* not a single memory resource was applicable */ - if (need_zonelists_rebuild) - zone_pcp_reset(zone); - goto failed_addition; - } - - zone->present_pages += onlined_pages; - - pgdat_resize_lock(zone->zone_pgdat, &flags); - zone->zone_pgdat->node_present_pages += onlined_pages; - pgdat_resize_unlock(zone->zone_pgdat, &flags); - - shuffle_zone(zone); + online_pages_range(pfn, nr_pages); + adjust_present_page_count(pfn_to_page(pfn), group, nr_pages); node_states_set_node(nid, &arg); if (need_zonelists_rebuild) build_all_zonelists(NULL); - else - zone_pcp_update(zone); + /* Basic onlining is complete, allow allocation of onlined pages. */ + undo_isolate_page_range(pfn, pfn + nr_pages, MIGRATE_MOVABLE); + + /* + * Freshly onlined pages aren't shuffled (e.g., all pages are placed to + * the tail of the freelist when undoing isolation). Shuffle the whole + * zone to make sure the just onlined pages are properly distributed + * across the whole freelist - to create an initial shuffle. + */ + shuffle_zone(zone); + + /* reinitialise watermarks and update pcp limits */ init_per_zone_wmark_min(); kswapd_run(nid); kcompactd_run(nid); - vm_total_pages = nr_free_pagecache_pages(); - writeback_set_ratelimit(); memory_notify(MEM_ONLINE, &arg); @@ -844,7 +1160,6 @@ failed_addition: mem_hotplug_done(); return ret; } -#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ static void reset_node_present_pages(pg_data_t *pgdat) { @@ -857,45 +1172,20 @@ static void reset_node_present_pages(pg_data_t *pgdat) } /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ -static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start) +static pg_data_t __ref *hotadd_init_pgdat(int nid) { struct pglist_data *pgdat; - unsigned long start_pfn = PFN_DOWN(start); + /* + * NODE_DATA is preallocated (free_area_init) but its internal + * state is not allocated completely. Add missing pieces. + * Completely offline nodes stay around and they just need + * reintialization. + */ pgdat = NODE_DATA(nid); - if (!pgdat) { - pgdat = arch_alloc_nodedata(nid); - if (!pgdat) - return NULL; - - pgdat->per_cpu_nodestats = - alloc_percpu(struct per_cpu_nodestat); - arch_refresh_nodedata(nid, pgdat); - } else { - int cpu; - /* - * Reset the nr_zones, order and classzone_idx before reuse. - * Note that kswapd will init kswapd_classzone_idx properly - * when it starts in the near future. - */ - pgdat->nr_zones = 0; - pgdat->kswapd_order = 0; - pgdat->kswapd_classzone_idx = 0; - for_each_online_cpu(cpu) { - struct per_cpu_nodestat *p; - - p = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu); - memset(p, 0, sizeof(*p)); - } - } - - /* we can use NODE_DATA(nid) from here */ - - pgdat->node_id = nid; - pgdat->node_start_pfn = start_pfn; /* init node's zones as empty zones, we don't have any present pages.*/ - free_area_init_core_hotplug(nid); + free_area_init_core_hotplug(pgdat); /* * The node we allocated has no zone fallback lists. For avoiding @@ -907,6 +1197,7 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start) * When memory is hot-added, all the memory is in offline state. So * clear all zones' present_pages because they will be updated in * online_pages() and offline_pages(). + * TODO: should be in free_area_init_core_hotplug? */ reset_node_managed_pages(pgdat); reset_node_present_pages(pgdat); @@ -914,20 +1205,9 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start) return pgdat; } -static void rollback_node_hotadd(int nid) -{ - pg_data_t *pgdat = NODE_DATA(nid); - - arch_refresh_nodedata(nid, NULL); - free_percpu(pgdat->per_cpu_nodestats); - arch_free_nodedata(pgdat); -} - - -/** - * try_online_node - online a node if offlined +/* + * __try_online_node - online a node if offlined * @nid: the node ID - * @start: start addr of the node * @set_node_online: Whether we want to online the node * called by cpu_up() to online a node without onlined memory. * @@ -936,7 +1216,7 @@ static void rollback_node_hotadd(int nid) * 0 -> the node is already online * -ENOMEM -> the node could not be allocated */ -static int __try_online_node(int nid, u64 start, bool set_node_online) +static int __try_online_node(int nid, bool set_node_online) { pg_data_t *pgdat; int ret = 1; @@ -944,7 +1224,7 @@ static int __try_online_node(int nid, u64 start, bool set_node_online) if (node_online(nid)) return 0; - pgdat = hotadd_new_pgdat(nid, start); + pgdat = hotadd_init_pgdat(nid); if (!pgdat) { pr_err("Cannot online node %d due to NULL pgdat\n", nid); ret = -ENOMEM; @@ -968,7 +1248,7 @@ int try_online_node(int nid) int ret; mem_hotplug_begin(); - ret = __try_online_node(nid, 0, true); + ret = __try_online_node(nid, true); mem_hotplug_done(); return ret; } @@ -988,18 +1268,60 @@ static int check_hotplug_memory_range(u64 start, u64 size) static int online_memory_block(struct memory_block *mem, void *arg) { + mem->online_type = mhp_default_online_type; return device_online(&mem->dev); } +bool mhp_supports_memmap_on_memory(unsigned long size) +{ + unsigned long nr_vmemmap_pages = size / PAGE_SIZE; + unsigned long vmemmap_size = nr_vmemmap_pages * sizeof(struct page); + unsigned long remaining_size = size - vmemmap_size; + + /* + * Besides having arch support and the feature enabled at runtime, we + * need a few more assumptions to hold true: + * + * a) We span a single memory block: memory onlining/offlinin;g happens + * in memory block granularity. We don't want the vmemmap of online + * memory blocks to reside on offline memory blocks. In the future, + * we might want to support variable-sized memory blocks to make the + * feature more versatile. + * + * b) The vmemmap pages span complete PMDs: We don't want vmemmap code + * to populate memory from the altmap for unrelated parts (i.e., + * other memory blocks) + * + * c) The vmemmap pages (and thereby the pages that will be exposed to + * the buddy) have to cover full pageblocks: memory onlining/offlining + * code requires applicable ranges to be page-aligned, for example, to + * set the migratetypes properly. + * + * TODO: Although we have a check here to make sure that vmemmap pages + * fully populate a PMD, it is not the right place to check for + * this. A much better solution involves improving vmemmap code + * to fallback to base pages when trying to populate vmemmap using + * altmap as an alternative source of memory, and we do not exactly + * populate a single PMD. + */ + return mhp_memmap_on_memory() && + size == memory_block_size_bytes() && + IS_ALIGNED(vmemmap_size, PMD_SIZE) && + IS_ALIGNED(remaining_size, (pageblock_nr_pages << PAGE_SHIFT)); +} + /* * NOTE: The caller must call lock_device_hotplug() to serialize hotplug * and online/offline operations (triggered e.g. by sysfs). * * we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ -int __ref add_memory_resource(int nid, struct resource *res) +int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags) { - struct mhp_restrictions restrictions = {}; + struct mhp_params params = { .pgprot = pgprot_mhp(PAGE_KERNEL) }; + enum memblock_flags memblock_flags = MEMBLOCK_NONE; + struct vmem_altmap mhp_altmap = {}; + struct memory_group *group = NULL; u64 start, size; bool new_node = false; int ret; @@ -1011,30 +1333,56 @@ int __ref add_memory_resource(int nid, struct resource *res) if (ret) return ret; + if (mhp_flags & MHP_NID_IS_MGID) { + group = memory_group_find_by_id(nid); + if (!group) + return -EINVAL; + nid = group->nid; + } + + if (!node_possible(nid)) { + WARN(1, "node %d was absent from the node_possible_map\n", nid); + return -EINVAL; + } + mem_hotplug_begin(); - /* - * Add new range to memblock so that when hotadd_new_pgdat() is called - * to allocate new pgdat, get_pfn_range_for_nid() will be able to find - * this new range and calculate total pages correctly. The range will - * be removed at hot-remove time. - */ - memblock_add_node(start, size, nid); + if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) { + if (res->flags & IORESOURCE_SYSRAM_DRIVER_MANAGED) + memblock_flags = MEMBLOCK_DRIVER_MANAGED; + ret = memblock_add_node(start, size, nid, memblock_flags); + if (ret) + goto error_mem_hotplug_end; + } - ret = __try_online_node(nid, start, false); + ret = __try_online_node(nid, false); if (ret < 0) goto error; new_node = ret; + /* + * Self hosted memmap array + */ + if (mhp_flags & MHP_MEMMAP_ON_MEMORY) { + if (!mhp_supports_memmap_on_memory(size)) { + ret = -EINVAL; + goto error; + } + mhp_altmap.free = PHYS_PFN(size); + mhp_altmap.base_pfn = PHYS_PFN(start); + params.altmap = &mhp_altmap; + } + /* call arch's memory hotadd */ - ret = arch_add_memory(nid, start, size, &restrictions); + ret = arch_add_memory(nid, start, size, ¶ms); if (ret < 0) goto error; /* create memory block devices after memory was added */ - ret = create_memory_block_devices(start, size); + ret = create_memory_block_devices(start, size, mhp_altmap.alloc, + group); if (ret) { - arch_remove_memory(nid, start, size, NULL); + arch_remove_memory(start, size, NULL); goto error; } @@ -1049,180 +1397,184 @@ int __ref add_memory_resource(int nid, struct resource *res) BUG_ON(ret); } - /* link memory sections under this node.*/ - ret = link_mem_sections(nid, PFN_DOWN(start), PFN_UP(start + size - 1)); - BUG_ON(ret); + register_memory_blocks_under_node(nid, PFN_DOWN(start), + PFN_UP(start + size - 1), + MEMINIT_HOTPLUG); /* create new memmap entry */ - firmware_map_add_hotplug(start, start + size, "System RAM"); + if (!strcmp(res->name, "System RAM")) + firmware_map_add_hotplug(start, start + size, "System RAM"); /* device_online() will take the lock when calling online_pages() */ mem_hotplug_done(); + /* + * In case we're allowed to merge the resource, flag it and trigger + * merging now that adding succeeded. + */ + if (mhp_flags & MHP_MERGE_RESOURCE) + merge_system_ram_resource(res); + /* online pages if requested */ - if (memhp_auto_online) + if (mhp_default_online_type != MMOP_OFFLINE) walk_memory_blocks(start, size, NULL, online_memory_block); return ret; error: - /* rollback pgdat allocation and others */ - if (new_node) - rollback_node_hotadd(nid); - memblock_remove(start, size); + if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) + memblock_remove(start, size); +error_mem_hotplug_end: mem_hotplug_done(); return ret; } /* requires device_hotplug_lock, see add_memory_resource() */ -int __ref __add_memory(int nid, u64 start, u64 size) +int __ref __add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags) { struct resource *res; int ret; - res = register_memory_resource(start, size); + res = register_memory_resource(start, size, "System RAM"); if (IS_ERR(res)) return PTR_ERR(res); - ret = add_memory_resource(nid, res); + ret = add_memory_resource(nid, res, mhp_flags); if (ret < 0) release_memory_resource(res); return ret; } -int add_memory(int nid, u64 start, u64 size) +int add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags) { int rc; lock_device_hotplug(); - rc = __add_memory(nid, start, size); + rc = __add_memory(nid, start, size, mhp_flags); unlock_device_hotplug(); return rc; } EXPORT_SYMBOL_GPL(add_memory); -#ifdef CONFIG_MEMORY_HOTREMOVE /* - * A free page on the buddy free lists (not the per-cpu lists) has PageBuddy - * set and the size of the free page is given by page_order(). Using this, - * the function determines if the pageblock contains only free pages. - * Due to buddy contraints, a free page at least the size of a pageblock will - * be located at the start of the pageblock + * Add special, driver-managed memory to the system as system RAM. Such + * memory is not exposed via the raw firmware-provided memmap as system + * RAM, instead, it is detected and added by a driver - during cold boot, + * after a reboot, and after kexec. + * + * Reasons why this memory should not be used for the initial memmap of a + * kexec kernel or for placing kexec images: + * - The booting kernel is in charge of determining how this memory will be + * used (e.g., use persistent memory as system RAM) + * - Coordination with a hypervisor is required before this memory + * can be used (e.g., inaccessible parts). + * + * For this memory, no entries in /sys/firmware/memmap ("raw firmware-provided + * memory map") are created. Also, the created memory resource is flagged + * with IORESOURCE_SYSRAM_DRIVER_MANAGED, so in-kernel users can special-case + * this memory as well (esp., not place kexec images onto it). + * + * The resource_name (visible via /proc/iomem) has to have the format + * "System RAM ($DRIVER)". */ -static inline int pageblock_free(struct page *page) +int add_memory_driver_managed(int nid, u64 start, u64 size, + const char *resource_name, mhp_t mhp_flags) { - return PageBuddy(page) && page_order(page) >= pageblock_order; -} + struct resource *res; + int rc; -/* Return the pfn of the start of the next active pageblock after a given pfn */ -static unsigned long next_active_pageblock(unsigned long pfn) -{ - struct page *page = pfn_to_page(pfn); + if (!resource_name || + strstr(resource_name, "System RAM (") != resource_name || + resource_name[strlen(resource_name) - 1] != ')') + return -EINVAL; - /* Ensure the starting page is pageblock-aligned */ - BUG_ON(pfn & (pageblock_nr_pages - 1)); + lock_device_hotplug(); - /* If the entire pageblock is free, move to the end of free page */ - if (pageblock_free(page)) { - int order; - /* be careful. we don't have locks, page_order can be changed.*/ - order = page_order(page); - if ((order < MAX_ORDER) && (order >= pageblock_order)) - return pfn + (1 << order); + res = register_memory_resource(start, size, resource_name); + if (IS_ERR(res)) { + rc = PTR_ERR(res); + goto out_unlock; } - return pfn + pageblock_nr_pages; + rc = add_memory_resource(nid, res, mhp_flags); + if (rc < 0) + release_memory_resource(res); + +out_unlock: + unlock_device_hotplug(); + return rc; } +EXPORT_SYMBOL_GPL(add_memory_driver_managed); -static bool is_pageblock_removable_nolock(unsigned long pfn) +/* + * Platforms should define arch_get_mappable_range() that provides + * maximum possible addressable physical memory range for which the + * linear mapping could be created. The platform returned address + * range must adhere to these following semantics. + * + * - range.start <= range.end + * - Range includes both end points [range.start..range.end] + * + * There is also a fallback definition provided here, allowing the + * entire possible physical address range in case any platform does + * not define arch_get_mappable_range(). + */ +struct range __weak arch_get_mappable_range(void) { - struct page *page = pfn_to_page(pfn); - struct zone *zone; - - /* - * We have to be careful here because we are iterating over memory - * sections which are not zone aware so we might end up outside of - * the zone but still within the section. - * We have to take care about the node as well. If the node is offline - * its NODE_DATA will be NULL - see page_zone. - */ - if (!node_online(page_to_nid(page))) - return false; - - zone = page_zone(page); - pfn = page_to_pfn(page); - if (!zone_spans_pfn(zone, pfn)) - return false; - - return !has_unmovable_pages(zone, page, MIGRATE_MOVABLE, - MEMORY_OFFLINE); + struct range mhp_range = { + .start = 0UL, + .end = -1ULL, + }; + return mhp_range; } -/* Checks if this range of memory is likely to be hot-removable. */ -bool is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages) +struct range mhp_get_pluggable_range(bool need_mapping) { - unsigned long end_pfn, pfn; - - end_pfn = min(start_pfn + nr_pages, - zone_end_pfn(page_zone(pfn_to_page(start_pfn)))); + const u64 max_phys = (1ULL << MAX_PHYSMEM_BITS) - 1; + struct range mhp_range; - /* Check the starting page of each pageblock within the range */ - for (pfn = start_pfn; pfn < end_pfn; pfn = next_active_pageblock(pfn)) { - if (!is_pageblock_removable_nolock(pfn)) - return false; - cond_resched(); + if (need_mapping) { + mhp_range = arch_get_mappable_range(); + if (mhp_range.start > max_phys) { + mhp_range.start = 0; + mhp_range.end = 0; + } + mhp_range.end = min_t(u64, mhp_range.end, max_phys); + } else { + mhp_range.start = 0; + mhp_range.end = max_phys; } - - /* All pageblocks in the memory block are likely to be hot-removable */ - return true; + return mhp_range; } +EXPORT_SYMBOL_GPL(mhp_get_pluggable_range); -/* - * Confirm all pages in a range [start, end) belong to the same zone (skipping - * memory holes). When true, return the zone. - */ -struct zone *test_pages_in_a_zone(unsigned long start_pfn, - unsigned long end_pfn) +bool mhp_range_allowed(u64 start, u64 size, bool need_mapping) { - unsigned long pfn, sec_end_pfn; - struct zone *zone = NULL; - struct page *page; - int i; - for (pfn = start_pfn, sec_end_pfn = SECTION_ALIGN_UP(start_pfn + 1); - pfn < end_pfn; - pfn = sec_end_pfn, sec_end_pfn += PAGES_PER_SECTION) { - /* Make sure the memory section is present first */ - if (!present_section_nr(pfn_to_section_nr(pfn))) - continue; - for (; pfn < sec_end_pfn && pfn < end_pfn; - pfn += MAX_ORDER_NR_PAGES) { - i = 0; - /* This is just a CONFIG_HOLES_IN_ZONE check.*/ - while ((i < MAX_ORDER_NR_PAGES) && - !pfn_valid_within(pfn + i)) - i++; - if (i == MAX_ORDER_NR_PAGES || pfn + i >= end_pfn) - continue; - /* Check if we got outside of the zone */ - if (zone && !zone_spans_pfn(zone, pfn + i)) - return NULL; - page = pfn_to_page(pfn + i); - if (zone && page_zone(page) != zone) - return NULL; - zone = page_zone(page); - } - } + struct range mhp_range = mhp_get_pluggable_range(need_mapping); + u64 end = start + size; + + if (start < end && start >= mhp_range.start && (end - 1) <= mhp_range.end) + return true; - return zone; + pr_warn("Hotplug memory [%#llx-%#llx] exceeds maximum addressable range [%#llx-%#llx]\n", + start, end, mhp_range.start, mhp_range.end); + return false; } +#ifdef CONFIG_MEMORY_HOTREMOVE /* * Scan pfn range [start,end) to find movable/migratable pages (LRU pages, - * non-lru movable pages and hugepages). We scan pfn because it's much - * easier than scanning over linked list. This function returns the pfn - * of the first found movable page if it's found, otherwise 0. + * non-lru movable pages and hugepages). Will skip over most unmovable + * pages (esp., pages that can be skipped when offlining), but bail out on + * definitely unmovable pages. + * + * Returns: + * 0 in case a movable page is found and movable_pfn was updated. + * -ENOENT in case no movable page was found. + * -EBUSY in case a definitely unmovable page was found. */ -static unsigned long scan_movable_pages(unsigned long start, unsigned long end) +static int scan_movable_pages(unsigned long start, unsigned long end, + unsigned long *movable_pfn) { unsigned long pfn; @@ -1234,59 +1586,65 @@ static unsigned long scan_movable_pages(unsigned long start, unsigned long end) continue; page = pfn_to_page(pfn); if (PageLRU(page)) - return pfn; + goto found; if (__PageMovable(page)) - return pfn; + goto found; + + /* + * PageOffline() pages that are not marked __PageMovable() and + * have a reference count > 0 (after MEM_GOING_OFFLINE) are + * definitely unmovable. If their reference count would be 0, + * they could at least be skipped when offlining memory. + */ + if (PageOffline(page) && page_count(page)) + return -EBUSY; if (!PageHuge(page)) continue; head = compound_head(page); - if (page_huge_active(head)) - return pfn; + /* + * This test is racy as we hold no reference or lock. The + * hugetlb page could have been free'ed and head is no longer + * a hugetlb page before the following check. In such unlikely + * cases false positives and negatives are possible. Calling + * code must deal with these scenarios. + */ + if (HPageMigratable(head)) + goto found; skip = compound_nr(head) - (page - head); pfn += skip - 1; } + return -ENOENT; +found: + *movable_pfn = pfn; return 0; } -static struct page *new_node_page(struct page *page, unsigned long private) -{ - int nid = page_to_nid(page); - nodemask_t nmask = node_states[N_MEMORY]; - - /* - * try to allocate from a different node but reuse this node if there - * are no other online nodes to be used (e.g. we are offlining a part - * of the only existing node) - */ - node_clear(nid, nmask); - if (nodes_empty(nmask)) - node_set(nid, nmask); - - return new_page_nodemask(page, nid, &nmask); -} - static int do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) { unsigned long pfn; - struct page *page; + struct page *page, *head; int ret = 0; LIST_HEAD(source); + static DEFINE_RATELIMIT_STATE(migrate_rs, DEFAULT_RATELIMIT_INTERVAL, + DEFAULT_RATELIMIT_BURST); for (pfn = start_pfn; pfn < end_pfn; pfn++) { + struct folio *folio; + if (!pfn_valid(pfn)) continue; page = pfn_to_page(pfn); + folio = page_folio(page); + head = &folio->page; if (PageHuge(page)) { - struct page *head = compound_head(page); pfn = page_to_pfn(head) + compound_nr(head) - 1; - isolate_huge_page(head, &source); + isolate_hugetlb(head, &source); continue; } else if (PageTransHuge(page)) - pfn = page_to_pfn(compound_head(page)) - + hpage_nr_pages(page) - 1; + pfn = page_to_pfn(head) + thp_nr_pages(page) - 1; /* * HWPoison pages have elevated reference counts so the migration would @@ -1296,10 +1654,10 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) * the unmap as the catch all safety net). */ if (PageHWPoison(page)) { - if (WARN_ON(PageLRU(page))) - isolate_lru_page(page); - if (page_mapped(page)) - try_to_unmap(page, TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS); + if (WARN_ON(folio_test_lru(folio))) + folio_isolate_lru(folio); + if (folio_mapped(folio)) + try_to_unmap(folio, TTU_IGNORE_MLOCK); continue; } @@ -1317,23 +1675,46 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) list_add_tail(&page->lru, &source); if (!__PageMovable(page)) inc_node_page_state(page, NR_ISOLATED_ANON + - page_is_file_cache(page)); + page_is_file_lru(page)); } else { - pr_warn("failed to isolate pfn %lx\n", pfn); - dump_page(page, "isolation failed"); + if (__ratelimit(&migrate_rs)) { + pr_warn("failed to isolate pfn %lx\n", pfn); + dump_page(page, "isolation failed"); + } } put_page(page); } if (!list_empty(&source)) { - /* Allocate a new page from the nearest neighbor node */ - ret = migrate_pages(&source, new_node_page, NULL, 0, - MIGRATE_SYNC, MR_MEMORY_HOTPLUG); + nodemask_t nmask = node_states[N_MEMORY]; + struct migration_target_control mtc = { + .nmask = &nmask, + .gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL, + }; + + /* + * We have checked that migration range is on a single zone so + * we can use the nid of the first page to all the others. + */ + mtc.nid = page_to_nid(list_first_entry(&source, struct page, lru)); + + /* + * try to allocate from a different node but reuse this node + * if there are no other online nodes to be used (e.g. we are + * offlining a part of the only existing node) + */ + node_clear(mtc.nid, nmask); + if (nodes_empty(nmask)) + node_set(mtc.nid, nmask); + ret = migrate_pages(&source, alloc_migration_target, NULL, + (unsigned long)&mtc, MIGRATE_SYNC, MR_MEMORY_HOTPLUG, NULL); if (ret) { list_for_each_entry(page, &source, lru) { - pr_warn("migrating pfn %lx failed ret:%d ", - page_to_pfn(page), ret); - dump_page(page, "migration failure"); + if (__ratelimit(&migrate_rs)) { + pr_warn("migrating pfn %lx failed ret:%d\n", + page_to_pfn(page), ret); + dump_page(page, "migration failure"); + } } putback_movable_pages(&source); } @@ -1342,35 +1723,9 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) return ret; } -/* Mark all sections offline and remove all free pages from the buddy. */ -static int -offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages, - void *data) -{ - unsigned long *offlined_pages = (unsigned long *)data; - - *offlined_pages += __offline_isolated_pages(start, start + nr_pages); - return 0; -} - -/* - * Check all pages in range, recoreded as memory resource, are isolated. - */ -static int -check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages, - void *data) -{ - return test_pages_isolated(start_pfn, start_pfn + nr_pages, - MEMORY_OFFLINE); -} - 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); @@ -1385,7 +1740,6 @@ static void node_states_check_changes_offline(unsigned long nr_pages, arg->status_change_nid = NUMA_NO_NODE; arg->status_change_nid_normal = NUMA_NO_NODE; - arg->status_change_nid_high = NUMA_NO_NODE; /* * Check whether node_states[N_NORMAL_MEMORY] will be changed. @@ -1400,24 +1754,9 @@ static void node_states_check_changes_offline(unsigned long nr_pages, if (zone_idx(zone) <= ZONE_NORMAL && nr_pages >= present_pages) arg->status_change_nid_normal = zone_to_nid(zone); -#ifdef CONFIG_HIGHMEM - /* - * node_states[N_HIGH_MEMORY] contains nodes which - * have normal memory or high memory. - * Here we add the present_pages belonging to ZONE_HIGHMEM. - * If the zone is within the range of [0..ZONE_HIGHMEM), and - * we determine that the zones in that range become empty, - * we need to clear the node for N_HIGH_MEMORY. - */ - present_pages += pgdat->node_zones[ZONE_HIGHMEM].present_pages; - if (zone_idx(zone) <= ZONE_HIGHMEM && nr_pages >= present_pages) - arg->status_change_nid_high = zone_to_nid(zone); -#endif - /* - * We have accounted the pages from [0..ZONE_NORMAL), and - * in case of CONFIG_HIGHMEM the pages from ZONE_HIGHMEM - * as well. + * We have accounted the pages from [0..ZONE_NORMAL); ZONE_HIGHMEM + * does not apply as we don't support 32bit. * Here we count the possible pages from ZONE_MOVABLE. * If after having accounted all the pages, we see that the nr_pages * to be offlined is over or equal to the accounted pages, @@ -1435,9 +1774,6 @@ static void node_states_clear_node(int node, struct memory_notify *arg) if (arg->status_change_nid_normal >= 0) node_clear_state(node, N_NORMAL_MEMORY); - if (arg->status_change_nid_high >= 0) - node_clear_state(node, N_HIGH_MEMORY); - if (arg->status_change_nid >= 0) node_clear_state(node, N_MEMORY); } @@ -1451,16 +1787,27 @@ static int count_system_ram_pages_cb(unsigned long start_pfn, return 0; } -static int __ref __offline_pages(unsigned long start_pfn, - unsigned long end_pfn) +int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages, + struct zone *zone, struct memory_group *group) { - unsigned long pfn, nr_pages = 0; - unsigned long offlined_pages = 0; - int ret, node, nr_isolate_pageblock; + const unsigned long end_pfn = start_pfn + nr_pages; + unsigned long pfn, system_ram_pages = 0; + const int node = zone_to_nid(zone); unsigned long flags; - struct zone *zone; struct memory_notify arg; char *reason; + int ret; + + /* + * {on,off}lining is constrained to full memory sections (or more + * precisely to memory blocks from the user space POV). + * memmap_on_memory is an exception because it reserves initial part + * of the physical memory space for vmemmaps. That space is pageblock + * aligned. + */ + if (WARN_ON_ONCE(!nr_pages || !pageblock_aligned(start_pfn) || + !IS_ALIGNED(start_pfn + nr_pages, PAGES_PER_SECTION))) + return -EINVAL; mem_hotplug_begin(); @@ -1472,33 +1819,42 @@ static int __ref __offline_pages(unsigned long start_pfn, * memory holes PG_reserved, don't need pfn_valid() checks, and can * avoid using walk_system_ram_range() later. */ - walk_system_ram_range(start_pfn, end_pfn - start_pfn, &nr_pages, + walk_system_ram_range(start_pfn, nr_pages, &system_ram_pages, count_system_ram_pages_cb); - if (nr_pages != end_pfn - start_pfn) { + if (system_ram_pages != nr_pages) { ret = -EINVAL; reason = "memory holes"; goto failed_removal; } - /* This makes hotplug much easier...and readable. - we assume this for now. .*/ - zone = test_pages_in_a_zone(start_pfn, end_pfn); - if (!zone) { + /* + * We only support offlining of memory blocks managed by a single zone, + * checked by calling code. This is just a sanity check that we might + * want to remove in the future. + */ + if (WARN_ON_ONCE(page_zone(pfn_to_page(start_pfn)) != zone || + page_zone(pfn_to_page(end_pfn - 1)) != zone)) { ret = -EINVAL; reason = "multizone range"; goto failed_removal; } - node = zone_to_nid(zone); + + /* + * Disable pcplists so that page isolation cannot race with freeing + * in a way that pages from isolated pageblock are left on pcplists. + */ + zone_pcp_disable(zone); + lru_cache_disable(); /* set above range as isolated */ ret = start_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE, - MEMORY_OFFLINE | REPORT_FAILURE); - if (ret < 0) { + MEMORY_OFFLINE | REPORT_FAILURE, + GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL); + if (ret) { reason = "failure to isolate range"; - goto failed_removal; + goto failed_removal_pcplists_disabled; } - nr_isolate_pageblock = ret; arg.start_pfn = start_pfn; arg.nr_pages = nr_pages; @@ -1512,7 +1868,8 @@ static int __ref __offline_pages(unsigned long start_pfn, } do { - for (pfn = start_pfn; pfn;) { + pfn = start_pfn; + do { if (signal_pending(current)) { ret = -EINTR; reason = "signal backoff"; @@ -1520,16 +1877,20 @@ static int __ref __offline_pages(unsigned long start_pfn, } cond_resched(); - lru_add_drain_all(); - pfn = scan_movable_pages(pfn, end_pfn); - if (pfn) { + ret = scan_movable_pages(pfn, end_pfn, &pfn); + if (!ret) { /* * TODO: fatal migration failures should bail * out */ do_migrate_range(pfn, end_pfn); } + } while (!ret); + + if (ret != -ENOENT) { + reason = "unmovable page"; + goto failed_removal_isolated; } /* @@ -1542,48 +1903,45 @@ static int __ref __offline_pages(unsigned long start_pfn, reason = "failure to dissolve huge pages"; goto failed_removal_isolated; } - /* check again */ - ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn, - NULL, check_pages_isolated_cb); + + ret = test_pages_isolated(start_pfn, end_pfn, MEMORY_OFFLINE); + } while (ret); - /* Ok, all of our target is isolated. - We cannot do rollback at this point. */ - walk_system_ram_range(start_pfn, end_pfn - start_pfn, - &offlined_pages, offline_isolated_pages_cb); - pr_info("Offlined Pages %ld\n", offlined_pages); + /* Mark all sections offline and remove free pages from the buddy. */ + __offline_isolated_pages(start_pfn, end_pfn); + pr_debug("Offlined Pages %ld\n", nr_pages); + /* - * Onlining will reset pagetype flags and makes migrate type - * MOVABLE, so just need to decrease the number of isolated - * pageblocks zone counter here. + * The memory sections are marked offline, and the pageblock flags + * effectively stale; nobody should be touching them. Fixup the number + * of isolated pageblocks, memory onlining will properly revert this. */ spin_lock_irqsave(&zone->lock, flags); - zone->nr_isolate_pageblock -= nr_isolate_pageblock; + zone->nr_isolate_pageblock -= nr_pages / pageblock_nr_pages; spin_unlock_irqrestore(&zone->lock, flags); - /* removal success */ - adjust_managed_page_count(pfn_to_page(start_pfn), -offlined_pages); - zone->present_pages -= offlined_pages; + lru_cache_enable(); + zone_pcp_enable(zone); - pgdat_resize_lock(zone->zone_pgdat, &flags); - zone->zone_pgdat->node_present_pages -= offlined_pages; - pgdat_resize_unlock(zone->zone_pgdat, &flags); + /* removal success */ + adjust_managed_page_count(pfn_to_page(start_pfn), -nr_pages); + adjust_present_page_count(pfn_to_page(start_pfn), group, -nr_pages); + /* reinitialise watermarks and update pcp limits */ init_per_zone_wmark_min(); if (!populated_zone(zone)) { zone_pcp_reset(zone); build_all_zonelists(NULL); - } else - zone_pcp_update(zone); + } node_states_clear_node(node, &arg); if (arg.status_change_nid >= 0) { - kswapd_stop(node); kcompactd_stop(node); + kswapd_stop(node); } - vm_total_pages = nr_free_pagecache_pages(); writeback_set_ratelimit(); memory_notify(MEM_OFFLINE, &arg); @@ -1592,28 +1950,27 @@ static int __ref __offline_pages(unsigned long start_pfn, return 0; failed_removal_isolated: + /* pushback to free area */ undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE); memory_notify(MEM_CANCEL_OFFLINE, &arg); +failed_removal_pcplists_disabled: + lru_cache_enable(); + zone_pcp_enable(zone); failed_removal: pr_debug("memory offlining [mem %#010llx-%#010llx] failed due to %s\n", (unsigned long long) start_pfn << PAGE_SHIFT, ((unsigned long long) end_pfn << PAGE_SHIFT) - 1, reason); - /* pushback to free area */ mem_hotplug_done(); return ret; } -int offline_pages(unsigned long start_pfn, unsigned long nr_pages) -{ - return __offline_pages(start_pfn, start_pfn + nr_pages); -} - static int check_memblock_offlined_cb(struct memory_block *mem, void *arg) { - int ret = !is_memblock_offlined(mem); + int *nid = arg; - if (unlikely(ret)) { + *nid = mem->nid; + if (unlikely(mem->state != MEM_OFFLINE)) { phys_addr_t beginpa, endpa; beginpa = PFN_PHYS(section_nr_to_pfn(mem->start_section_nr)); @@ -1626,12 +1983,20 @@ static int check_memblock_offlined_cb(struct memory_block *mem, void *arg) return 0; } -static int check_cpu_on_node(pg_data_t *pgdat) +static int get_nr_vmemmap_pages_cb(struct memory_block *mem, void *arg) +{ + /* + * If not set, continue with the next block. + */ + return mem->nr_vmemmap_pages; +} + +static int check_cpu_on_node(int nid) { int cpu; for_each_present_cpu(cpu) { - if (cpu_to_node(cpu) == pgdat->node_id) + if (cpu_to_node(cpu) == nid) /* * the cpu on this node isn't removed, and we can't * offline this node. @@ -1665,7 +2030,6 @@ static int check_no_memblock_for_node_cb(struct memory_block *mem, void *arg) */ void try_offline_node(int nid) { - pg_data_t *pgdat = NODE_DATA(nid); int rc; /* @@ -1673,7 +2037,7 @@ void try_offline_node(int nid) * offline it. A node spans memory after move_pfn_range_to_zone(), * e.g., after the memory block was onlined. */ - if (pgdat->node_spanned_pages) + if (node_spanned_pages(nid)) return; /* @@ -1685,7 +2049,7 @@ void try_offline_node(int nid) if (rc) return; - if (check_cpu_on_node(pgdat)) + if (check_cpu_on_node(nid)) return; /* @@ -1697,29 +2061,12 @@ void try_offline_node(int nid) } EXPORT_SYMBOL(try_offline_node); -static void __release_memory_resource(resource_size_t start, - resource_size_t size) -{ - int ret; - - /* - * When removing memory in the same granularity as it was added, - * this function never fails. It might only fail if resources - * have to be adjusted or split. We'll ignore the error, as - * removing of memory cannot fail. - */ - ret = release_mem_region_adjustable(&iomem_resource, start, size); - if (ret) { - resource_size_t endres = start + size - 1; - - pr_warn("Unable to release resource <%pa-%pa> (%d)\n", - &start, &endres, ret); - } -} - -static int __ref try_remove_memory(int nid, u64 start, u64 size) +static int __ref try_remove_memory(u64 start, u64 size) { - int rc = 0; + struct vmem_altmap mhp_altmap = {}; + struct vmem_altmap *altmap = NULL; + unsigned long nr_vmemmap_pages; + int rc = 0, nid = NUMA_NO_NODE; BUG_ON(check_hotplug_memory_range(start, size)); @@ -1727,10 +2074,39 @@ static int __ref try_remove_memory(int nid, u64 start, u64 size) * All memory blocks must be offlined before removing memory. Check * whether all memory blocks in question are offline and return error * if this is not the case. + * + * While at it, determine the nid. Note that if we'd have mixed nodes, + * we'd only try to offline the last determined one -- which is good + * enough for the cases we care about. */ - rc = walk_memory_blocks(start, size, NULL, check_memblock_offlined_cb); + rc = walk_memory_blocks(start, size, &nid, check_memblock_offlined_cb); if (rc) - goto done; + return rc; + + /* + * We only support removing memory added with MHP_MEMMAP_ON_MEMORY in + * the same granularity it was added - a single memory block. + */ + if (mhp_memmap_on_memory()) { + nr_vmemmap_pages = walk_memory_blocks(start, size, NULL, + get_nr_vmemmap_pages_cb); + if (nr_vmemmap_pages) { + if (size != memory_block_size_bytes()) { + pr_warn("Refuse to remove %#llx - %#llx," + "wrong granularity\n", + start, start + size); + return -EINVAL; + } + + /* + * Let remove_pmd_table->free_hugepage_table do the + * right thing if we used vmem_altmap when hot-adding + * the range. + */ + mhp_altmap.alloc = nr_vmemmap_pages; + altmap = &mhp_altmap; + } + } /* remove memmap entry */ firmware_map_remove(start, start + size, "System RAM"); @@ -1743,21 +2119,24 @@ static int __ref try_remove_memory(int nid, u64 start, u64 size) mem_hotplug_begin(); - arch_remove_memory(nid, start, size, NULL); - memblock_free(start, size); - memblock_remove(start, size); - __release_memory_resource(start, size); + arch_remove_memory(start, size, altmap); + + if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) { + memblock_phys_free(start, size); + memblock_remove(start, size); + } + + release_mem_region_adjustable(start, size); - try_offline_node(nid); + if (nid != NUMA_NO_NODE) + try_offline_node(nid); -done: mem_hotplug_done(); - return rc; + return 0; } /** - * remove_memory - * @nid: the node ID + * __remove_memory - Remove memory if every memory block is offline * @start: physical address of the region to remove * @size: size of the region to remove * @@ -1765,14 +2144,14 @@ done: * and online/offline operations before this call, as required by * try_offline_node(). */ -void __remove_memory(int nid, u64 start, u64 size) +void __remove_memory(u64 start, u64 size) { /* * trigger BUG() if some memory is not offlined prior to calling this * function */ - if (try_remove_memory(nid, start, size)) + if (try_remove_memory(start, size)) BUG(); } @@ -1780,15 +2159,125 @@ void __remove_memory(int nid, u64 start, u64 size) * Remove memory if every memory block is offline, otherwise return -EBUSY is * some memory is not offline */ -int remove_memory(int nid, u64 start, u64 size) +int remove_memory(u64 start, u64 size) { int rc; lock_device_hotplug(); - rc = try_remove_memory(nid, start, size); + rc = try_remove_memory(start, size); unlock_device_hotplug(); return rc; } EXPORT_SYMBOL_GPL(remove_memory); + +static int try_offline_memory_block(struct memory_block *mem, void *arg) +{ + uint8_t online_type = MMOP_ONLINE_KERNEL; + uint8_t **online_types = arg; + struct page *page; + int rc; + + /* + * Sense the online_type via the zone of the memory block. Offlining + * with multiple zones within one memory block will be rejected + * by offlining code ... so we don't care about that. + */ + page = pfn_to_online_page(section_nr_to_pfn(mem->start_section_nr)); + if (page && zone_idx(page_zone(page)) == ZONE_MOVABLE) + online_type = MMOP_ONLINE_MOVABLE; + + rc = device_offline(&mem->dev); + /* + * Default is MMOP_OFFLINE - change it only if offlining succeeded, + * so try_reonline_memory_block() can do the right thing. + */ + if (!rc) + **online_types = online_type; + + (*online_types)++; + /* Ignore if already offline. */ + return rc < 0 ? rc : 0; +} + +static int try_reonline_memory_block(struct memory_block *mem, void *arg) +{ + uint8_t **online_types = arg; + int rc; + + if (**online_types != MMOP_OFFLINE) { + mem->online_type = **online_types; + rc = device_online(&mem->dev); + if (rc < 0) + pr_warn("%s: Failed to re-online memory: %d", + __func__, rc); + } + + /* Continue processing all remaining memory blocks. */ + (*online_types)++; + return 0; +} + +/* + * Try to offline and remove memory. Might take a long time to finish in case + * memory is still in use. Primarily useful for memory devices that logically + * unplugged all memory (so it's no longer in use) and want to offline + remove + * that memory. + */ +int offline_and_remove_memory(u64 start, u64 size) +{ + const unsigned long mb_count = size / memory_block_size_bytes(); + uint8_t *online_types, *tmp; + int rc; + + if (!IS_ALIGNED(start, memory_block_size_bytes()) || + !IS_ALIGNED(size, memory_block_size_bytes()) || !size) + return -EINVAL; + + /* + * We'll remember the old online type of each memory block, so we can + * try to revert whatever we did when offlining one memory block fails + * after offlining some others succeeded. + */ + online_types = kmalloc_array(mb_count, sizeof(*online_types), + GFP_KERNEL); + if (!online_types) + return -ENOMEM; + /* + * Initialize all states to MMOP_OFFLINE, so when we abort processing in + * try_offline_memory_block(), we'll skip all unprocessed blocks in + * try_reonline_memory_block(). + */ + memset(online_types, MMOP_OFFLINE, mb_count); + + lock_device_hotplug(); + + tmp = online_types; + rc = walk_memory_blocks(start, size, &tmp, try_offline_memory_block); + + /* + * In case we succeeded to offline all memory, remove it. + * This cannot fail as it cannot get onlined in the meantime. + */ + if (!rc) { + rc = try_remove_memory(start, size); + if (rc) + pr_err("%s: Failed to remove memory: %d", __func__, rc); + } + + /* + * Rollback what we did. While memory onlining might theoretically fail + * (nacked by a notifier), it barely ever happens. + */ + if (rc) { + tmp = online_types; + walk_memory_blocks(start, size, &tmp, + try_reonline_memory_block); + } + unlock_device_hotplug(); + + kfree(online_types); + return rc; +} +EXPORT_SYMBOL_GPL(offline_and_remove_memory); #endif /* CONFIG_MEMORY_HOTREMOVE */ |