diff options
Diffstat (limited to 'mm/memory_hotplug.c')
| -rw-r--r-- | mm/memory_hotplug.c | 567 |
1 files changed, 337 insertions, 230 deletions
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index b81a367b9f3..469bbf505f8 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -9,7 +9,6 @@ #include <linux/swap.h> #include <linux/interrupt.h> #include <linux/pagemap.h> -#include <linux/bootmem.h> #include <linux/compiler.h> #include <linux/export.h> #include <linux/pagevec.h> @@ -30,6 +29,8 @@ #include <linux/mm_inline.h> #include <linux/firmware-map.h> #include <linux/stop_machine.h> +#include <linux/hugetlb.h> +#include <linux/memblock.h> #include <asm/tlbflush.h> @@ -45,23 +46,84 @@ static void generic_online_page(struct page *page); static online_page_callback_t online_page_callback = generic_online_page; +static DEFINE_MUTEX(online_page_callback_lock); -DEFINE_MUTEX(mem_hotplug_mutex); +/* The same as the cpu_hotplug lock, but for memory hotplug. */ +static struct { + struct task_struct *active_writer; + struct mutex lock; /* Synchronizes accesses to refcount, */ + /* + * Also blocks the new readers during + * an ongoing mem hotplug operation. + */ + int refcount; + +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; +#endif +} mem_hotplug = { + .active_writer = NULL, + .lock = __MUTEX_INITIALIZER(mem_hotplug.lock), + .refcount = 0, +#ifdef CONFIG_DEBUG_LOCK_ALLOC + .dep_map = {.name = "mem_hotplug.lock" }, +#endif +}; + +/* Lockdep annotations for get/put_online_mems() and mem_hotplug_begin/end() */ +#define memhp_lock_acquire_read() lock_map_acquire_read(&mem_hotplug.dep_map) +#define memhp_lock_acquire() lock_map_acquire(&mem_hotplug.dep_map) +#define memhp_lock_release() lock_map_release(&mem_hotplug.dep_map) + +void get_online_mems(void) +{ + might_sleep(); + if (mem_hotplug.active_writer == current) + return; + memhp_lock_acquire_read(); + mutex_lock(&mem_hotplug.lock); + mem_hotplug.refcount++; + mutex_unlock(&mem_hotplug.lock); + +} -void lock_memory_hotplug(void) +void put_online_mems(void) { - mutex_lock(&mem_hotplug_mutex); + if (mem_hotplug.active_writer == current) + return; + mutex_lock(&mem_hotplug.lock); + + if (WARN_ON(!mem_hotplug.refcount)) + mem_hotplug.refcount++; /* try to fix things up */ + + if (!--mem_hotplug.refcount && unlikely(mem_hotplug.active_writer)) + wake_up_process(mem_hotplug.active_writer); + mutex_unlock(&mem_hotplug.lock); + memhp_lock_release(); - /* for exclusive hibernation if CONFIG_HIBERNATION=y */ - lock_system_sleep(); } -void unlock_memory_hotplug(void) +static void mem_hotplug_begin(void) { - unlock_system_sleep(); - mutex_unlock(&mem_hotplug_mutex); + mem_hotplug.active_writer = current; + + memhp_lock_acquire(); + for (;;) { + mutex_lock(&mem_hotplug.lock); + if (likely(!mem_hotplug.refcount)) + break; + __set_current_state(TASK_UNINTERRUPTIBLE); + mutex_unlock(&mem_hotplug.lock); + schedule(); + } } +static void mem_hotplug_done(void) +{ + mem_hotplug.active_writer = NULL; + mutex_unlock(&mem_hotplug.lock); + memhp_lock_release(); +} /* add this memory to iomem resource */ static struct resource *register_memory_resource(u64 start, u64 size) @@ -75,7 +137,7 @@ static struct resource *register_memory_resource(u64 start, u64 size) res->end = start + size - 1; res->flags = IORESOURCE_MEM | IORESOURCE_BUSY; if (request_resource(&iomem_resource, res) < 0) { - printk("System RAM resource %pR cannot be added\n", res); + pr_debug("System RAM resource %pR cannot be added\n", res); kfree(res); res = NULL; } @@ -101,12 +163,9 @@ void get_page_bootmem(unsigned long info, struct page *page, atomic_inc(&page->_count); } -/* reference to __meminit __free_pages_bootmem is valid - * so use __ref to tell modpost not to generate a warning */ -void __ref put_page_bootmem(struct page *page) +void put_page_bootmem(struct page *page) { unsigned long type; - static DEFINE_MUTEX(ppb_lock); type = (unsigned long) page->lru.next; BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE || @@ -116,17 +175,8 @@ void __ref put_page_bootmem(struct page *page) ClearPagePrivate(page); set_page_private(page, 0); INIT_LIST_HEAD(&page->lru); - - /* - * Please refer to comment for __free_pages_bootmem() - * for why we serialize here. - */ - mutex_lock(&ppb_lock); - __free_pages_bootmem(page, 0); - mutex_unlock(&ppb_lock); - totalram_pages++; + free_reserved_page(page); } - } #ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE @@ -206,7 +256,7 @@ void register_page_bootmem_info_node(struct pglist_data *pgdat) zone = &pgdat->node_zones[0]; for (; zone < pgdat->node_zones + MAX_NR_ZONES - 1; zone++) { - if (zone->wait_table) { + if (zone_is_initialized(zone)) { nr_pages = zone->wait_table_hash_nr_entries * sizeof(wait_queue_head_t); nr_pages = PAGE_ALIGN(nr_pages) >> PAGE_SHIFT; @@ -220,13 +270,13 @@ void register_page_bootmem_info_node(struct pglist_data *pgdat) pfn = pgdat->node_start_pfn; end_pfn = pgdat_end_pfn(pgdat); - /* register_section info */ + /* 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 node. + * reside in some other nodes. */ if (pfn_valid(pfn) && (pfn_to_nid(pfn) == node)) register_page_bootmem_info_section(pfn); @@ -241,8 +291,8 @@ static void grow_zone_span(struct zone *zone, unsigned long start_pfn, zone_span_writelock(zone); - old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages; - if (!zone->spanned_pages || start_pfn < zone->zone_start_pfn) + old_zone_end_pfn = zone_end_pfn(zone); + if (zone_is_empty(zone) || start_pfn < zone->zone_start_pfn) zone->zone_start_pfn = start_pfn; zone->spanned_pages = max(old_zone_end_pfn, end_pfn) - @@ -283,7 +333,7 @@ static void fix_zone_id(struct zone *zone, unsigned long start_pfn, } /* Can fail with -ENOMEM from allocating a wait table with vmalloc() or - * alloc_bootmem_node_nopanic() */ + * alloc_bootmem_node_nopanic()/memblock_virt_alloc_node_nopanic() */ static int __ref ensure_zone_is_initialized(struct zone *zone, unsigned long start_pfn, unsigned long num_pages) { @@ -309,7 +359,7 @@ static int __meminit move_pfn_range_left(struct zone *z1, struct zone *z2, /* can't move pfns which are higher than @z2 */ if (end_pfn > zone_end_pfn(z2)) goto out_fail; - /* the move out part mast at the left most of @z2 */ + /* the move out part must be at the left most of @z2 */ if (start_pfn > z2->zone_start_pfn) goto out_fail; /* must included/overlap */ @@ -317,7 +367,7 @@ static int __meminit move_pfn_range_left(struct zone *z1, struct zone *z2, goto out_fail; /* use start_pfn for z1's start_pfn if z1 is empty */ - if (z1->spanned_pages) + if (!zone_is_empty(z1)) z1_start_pfn = z1->zone_start_pfn; else z1_start_pfn = start_pfn; @@ -359,7 +409,7 @@ static int __meminit move_pfn_range_right(struct zone *z1, struct zone *z2, goto out_fail; /* use end_pfn for z2's end_pfn if z2 is empty */ - if (z2->spanned_pages) + if (!zone_is_empty(z2)) z2_end_pfn = zone_end_pfn(z2); else z2_end_pfn = end_pfn; @@ -380,8 +430,7 @@ out_fail: static void grow_pgdat_span(struct pglist_data *pgdat, unsigned long start_pfn, unsigned long end_pfn) { - unsigned long old_pgdat_end_pfn = - pgdat->node_start_pfn + pgdat->node_spanned_pages; + unsigned long old_pgdat_end_pfn = pgdat_end_pfn(pgdat); if (!pgdat->node_spanned_pages || start_pfn < pgdat->node_start_pfn) pgdat->node_start_pfn = start_pfn; @@ -417,13 +466,12 @@ static int __meminit __add_zone(struct zone *zone, unsigned long phys_start_pfn) static int __meminit __add_section(int nid, struct zone *zone, unsigned long phys_start_pfn) { - int nr_pages = PAGES_PER_SECTION; int ret; if (pfn_valid(phys_start_pfn)) return -EEXIST; - ret = sparse_add_one_section(zone, phys_start_pfn, nr_pages); + ret = sparse_add_one_section(zone, phys_start_pfn); if (ret < 0) return ret; @@ -436,6 +484,40 @@ static int __meminit __add_section(int nid, struct zone *zone, return register_new_memory(nid, __pfn_to_section(phys_start_pfn)); } +/* + * 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, struct zone *zone, unsigned long phys_start_pfn, + unsigned long nr_pages) +{ + unsigned long i; + int err = 0; + int start_sec, end_sec; + /* during initialize mem_map, align hot-added range to section */ + start_sec = pfn_to_section_nr(phys_start_pfn); + end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1); + + for (i = start_sec; i <= end_sec; i++) { + err = __add_section(nid, zone, i << PFN_SECTION_SHIFT); + + /* + * EEXIST is finally dealt with by ioresource collision + * check. see add_memory() => register_memory_resource() + * Warning will be printed if there is collision. + */ + if (err && (err != -EEXIST)) + break; + err = 0; + } + + return err; +} +EXPORT_SYMBOL_GPL(__add_pages); + +#ifdef CONFIG_MEMORY_HOTREMOVE /* find the smallest valid pfn in the range [start_pfn, end_pfn) */ static int find_smallest_section_pfn(int nid, struct zone *zone, unsigned long start_pfn, @@ -492,8 +574,9 @@ static int find_biggest_section_pfn(int nid, struct zone *zone, static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, unsigned long end_pfn) { - unsigned long zone_start_pfn = zone->zone_start_pfn; - unsigned long zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages; + unsigned long zone_start_pfn = zone->zone_start_pfn; + unsigned long z = zone_end_pfn(zone); /* zone_end_pfn namespace clash */ + unsigned long zone_end_pfn = z; unsigned long pfn; struct mem_section *ms; int nid = zone_to_nid(zone); @@ -559,9 +642,9 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, static void shrink_pgdat_span(struct pglist_data *pgdat, unsigned long start_pfn, unsigned long end_pfn) { - unsigned long pgdat_start_pfn = pgdat->node_start_pfn; - unsigned long pgdat_end_pfn = - pgdat->node_start_pfn + pgdat->node_spanned_pages; + unsigned long pgdat_start_pfn = pgdat->node_start_pfn; + unsigned long p = pgdat_end_pfn(pgdat); /* pgdat_end_pfn namespace clash */ + unsigned long pgdat_end_pfn = p; unsigned long pfn; struct mem_section *ms; int nid = pgdat->node_id; @@ -658,39 +741,6 @@ static int __remove_section(struct zone *zone, struct mem_section *ms) return 0; } -/* - * 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, struct zone *zone, unsigned long phys_start_pfn, - unsigned long nr_pages) -{ - unsigned long i; - int err = 0; - int start_sec, end_sec; - /* during initialize mem_map, align hot-added range to section */ - start_sec = pfn_to_section_nr(phys_start_pfn); - end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1); - - for (i = start_sec; i <= end_sec; i++) { - err = __add_section(nid, zone, i << PFN_SECTION_SHIFT); - - /* - * EEXIST is finally dealt with by ioresource collision - * check. see add_memory() => register_memory_resource() - * Warning will be printed if there is collision. - */ - if (err && (err != -EEXIST)) - break; - err = 0; - } - - return err; -} -EXPORT_SYMBOL_GPL(__add_pages); - /** * __remove_pages() - remove sections of pages from a zone * @zone: zone from which pages need to be removed @@ -705,8 +755,10 @@ EXPORT_SYMBOL_GPL(__add_pages); int __remove_pages(struct zone *zone, unsigned long phys_start_pfn, unsigned long nr_pages) { - unsigned long i, ret = 0; + unsigned long i; int sections_to_remove; + resource_size_t start, size; + int ret = 0; /* * We can only remove entire sections @@ -714,7 +766,15 @@ int __remove_pages(struct zone *zone, unsigned long phys_start_pfn, BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK); BUG_ON(nr_pages % PAGES_PER_SECTION); - release_mem_region(phys_start_pfn << PAGE_SHIFT, nr_pages * PAGE_SIZE); + start = phys_start_pfn << PAGE_SHIFT; + size = nr_pages * PAGE_SIZE; + 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); + } sections_to_remove = nr_pages / PAGES_PER_SECTION; for (i = 0; i < sections_to_remove; i++) { @@ -726,19 +786,22 @@ int __remove_pages(struct zone *zone, unsigned long phys_start_pfn, return ret; } EXPORT_SYMBOL_GPL(__remove_pages); +#endif /* CONFIG_MEMORY_HOTREMOVE */ int set_online_page_callback(online_page_callback_t callback) { int rc = -EINVAL; - lock_memory_hotplug(); + get_online_mems(); + mutex_lock(&online_page_callback_lock); if (online_page_callback == generic_online_page) { online_page_callback = callback; rc = 0; } - unlock_memory_hotplug(); + mutex_unlock(&online_page_callback_lock); + put_online_mems(); return rc; } @@ -748,14 +811,16 @@ int restore_online_page_callback(online_page_callback_t callback) { int rc = -EINVAL; - lock_memory_hotplug(); + get_online_mems(); + mutex_lock(&online_page_callback_lock); if (online_page_callback == callback) { online_page_callback = generic_online_page; rc = 0; } - unlock_memory_hotplug(); + mutex_unlock(&online_page_callback_lock); + put_online_mems(); return rc; } @@ -763,29 +828,18 @@ EXPORT_SYMBOL_GPL(restore_online_page_callback); void __online_page_set_limits(struct page *page) { - unsigned long pfn = page_to_pfn(page); - - if (pfn >= num_physpages) - num_physpages = pfn + 1; } EXPORT_SYMBOL_GPL(__online_page_set_limits); void __online_page_increment_counters(struct page *page) { - totalram_pages++; - -#ifdef CONFIG_HIGHMEM - if (PageHighMem(page)) - totalhigh_pages++; -#endif + adjust_managed_page_count(page, 1); } EXPORT_SYMBOL_GPL(__online_page_increment_counters); void __online_page_free(struct page *page) { - ClearPageReserved(page); - init_page_count(page); - __free_page(page); + __free_reserved_page(page); } EXPORT_SYMBOL_GPL(__online_page_free); @@ -906,6 +960,7 @@ static void node_states_set_node(int node, struct memory_notify *arg) int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_type) { + unsigned long flags; unsigned long onlined_pages = 0; struct zone *zone; int need_zonelists_rebuild = 0; @@ -913,7 +968,7 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ int ret; struct memory_notify arg; - lock_memory_hotplug(); + mem_hotplug_begin(); /* * This doesn't need a lock to do pfn_to_page(). * The section can't be removed here because of the @@ -921,23 +976,18 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ */ zone = page_zone(pfn_to_page(pfn)); + ret = -EINVAL; if ((zone_idx(zone) > ZONE_NORMAL || online_type == ONLINE_MOVABLE) && - !can_online_high_movable(zone)) { - unlock_memory_hotplug(); - return -1; - } + !can_online_high_movable(zone)) + goto out; if (online_type == ONLINE_KERNEL && zone_idx(zone) == ZONE_MOVABLE) { - if (move_pfn_range_left(zone - 1, zone, pfn, pfn + nr_pages)) { - unlock_memory_hotplug(); - return -1; - } + if (move_pfn_range_left(zone - 1, zone, pfn, pfn + nr_pages)) + goto out; } if (online_type == ONLINE_MOVABLE && zone_idx(zone) == ZONE_MOVABLE - 1) { - if (move_pfn_range_right(zone, zone + 1, pfn, pfn + nr_pages)) { - unlock_memory_hotplug(); - return -1; - } + if (move_pfn_range_right(zone, zone + 1, pfn, pfn + nr_pages)) + goto out; } /* Previous code may changed the zone of the pfn range */ @@ -947,14 +997,13 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ arg.nr_pages = nr_pages; node_states_check_changes_online(nr_pages, zone, &arg); - nid = page_to_nid(pfn_to_page(pfn)); + nid = pfn_to_nid(pfn); ret = memory_notify(MEM_GOING_ONLINE, &arg); ret = notifier_to_errno(ret); if (ret) { memory_notify(MEM_CANCEL_ONLINE, &arg); - unlock_memory_hotplug(); - return ret; + goto out; } /* * If this zone is not populated, then it is not in zonelist. @@ -978,13 +1027,15 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ (((unsigned long long) pfn + nr_pages) << PAGE_SHIFT) - 1); memory_notify(MEM_CANCEL_ONLINE, &arg); - unlock_memory_hotplug(); - return ret; + goto out; } - zone->managed_pages += onlined_pages; 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); + if (onlined_pages) { node_states_set_node(zone_to_nid(zone), &arg); if (need_zonelists_rebuild) @@ -1006,9 +1057,9 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ if (onlined_pages) memory_notify(MEM_ONLINE, &arg); - unlock_memory_hotplug(); - - return 0; +out: + mem_hotplug_done(); + return ret; } #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ @@ -1018,7 +1069,7 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start) struct pglist_data *pgdat; unsigned long zones_size[MAX_NR_ZONES] = {0}; unsigned long zholes_size[MAX_NR_ZONES] = {0}; - unsigned long start_pfn = start >> PAGE_SHIFT; + unsigned long start_pfn = PFN_DOWN(start); pgdat = NODE_DATA(nid); if (!pgdat) { @@ -1053,17 +1104,23 @@ static void rollback_node_hotadd(int nid, pg_data_t *pgdat) } -/* +/** + * try_online_node - online a node if offlined + * * called by cpu_up() to online a node without onlined memory. */ -int mem_online_node(int nid) +int try_online_node(int nid) { pg_data_t *pgdat; int ret; - lock_memory_hotplug(); + if (node_online(nid)) + return 0; + + mem_hotplug_begin(); pgdat = hotadd_new_pgdat(nid, 0); if (!pgdat) { + pr_err("Cannot online node %d due to NULL pgdat\n", nid); ret = -ENOMEM; goto out; } @@ -1071,11 +1128,34 @@ int mem_online_node(int nid) ret = register_one_node(nid); BUG_ON(ret); + if (pgdat->node_zonelists->_zonerefs->zone == NULL) { + mutex_lock(&zonelists_mutex); + build_all_zonelists(NULL, NULL); + mutex_unlock(&zonelists_mutex); + } + out: - unlock_memory_hotplug(); + mem_hotplug_done(); return ret; } +static int check_hotplug_memory_range(u64 start, u64 size) +{ + u64 start_pfn = PFN_DOWN(start); + u64 nr_pages = size >> PAGE_SHIFT; + + /* Memory range must be aligned with section */ + if ((start_pfn & ~PAGE_SECTION_MASK) || + (nr_pages % PAGES_PER_SECTION) || (!nr_pages)) { + pr_err("Section-unaligned hotplug range: start 0x%llx, size 0x%llx\n", + (unsigned long long)start, + (unsigned long long)size); + return -EINVAL; + } + + return 0; +} + /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ int __ref add_memory(int nid, u64 start, u64 size) { @@ -1085,17 +1165,22 @@ int __ref add_memory(int nid, u64 start, u64 size) struct resource *res; int ret; - lock_memory_hotplug(); + ret = check_hotplug_memory_range(start, size); + if (ret) + return ret; res = register_memory_resource(start, size); ret = -EEXIST; if (!res) - goto out; + return ret; { /* Stupid hack to suppress address-never-null warning */ void *p = NODE_DATA(nid); new_pgdat = !p; } + + mem_hotplug_begin(); + new_node = !node_online(nid); if (new_node) { pgdat = hotadd_new_pgdat(nid, start); @@ -1135,7 +1220,7 @@ error: release_memory_resource(res); out: - unlock_memory_hotplug(); + mem_hotplug_done(); return ret; } EXPORT_SYMBOL_GPL(add_memory); @@ -1215,10 +1300,12 @@ static int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn) } /* - * Scanning pfn is much easier than scanning lru list. - * Scan pfn from start to end and Find LRU page. + * Scan pfn range [start,end) to find movable/migratable pages (LRU 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. */ -static unsigned long scan_lru_pages(unsigned long start, unsigned long end) +static unsigned long scan_movable_pages(unsigned long start, unsigned long end) { unsigned long pfn; struct page *page; @@ -1227,6 +1314,13 @@ static unsigned long scan_lru_pages(unsigned long start, unsigned long end) page = pfn_to_page(pfn); if (PageLRU(page)) return pfn; + if (PageHuge(page)) { + if (is_hugepage_active(page)) + return pfn; + else + pfn = round_up(pfn + 1, + 1 << compound_order(page)) - 1; + } } } return 0; @@ -1247,6 +1341,19 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) if (!pfn_valid(pfn)) continue; page = pfn_to_page(pfn); + + if (PageHuge(page)) { + struct page *head = compound_head(page); + pfn = page_to_pfn(head) + (1<<compound_order(head)) - 1; + if (compound_order(head) > PFN_SECTION_SHIFT) { + ret = -EBUSY; + break; + } + if (isolate_huge_page(page, &source)) + move_pages -= 1 << compound_order(head); + continue; + } + if (!get_page_unless_zero(page)) continue; /* @@ -1265,7 +1372,7 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) #ifdef CONFIG_DEBUG_VM printk(KERN_ALERT "removing pfn %lx from LRU failed\n", pfn); - dump_page(page); + dump_page(page, "failed to remove from LRU"); #endif put_page(page); /* Because we don't have big zone->lock. we should @@ -1279,7 +1386,7 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) } if (!list_empty(&source)) { if (not_managed) { - putback_lru_pages(&source); + putback_movable_pages(&source); goto out; } @@ -1287,10 +1394,10 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) * alloc_migrate_target should be improooooved!! * migrate_pages returns # of failed pages. */ - ret = migrate_pages(&source, alloc_migrate_target, 0, + ret = migrate_pages(&source, alloc_migrate_target, NULL, 0, MIGRATE_SYNC, MR_MEMORY_HOTPLUG); if (ret) - putback_lru_pages(&source); + putback_movable_pages(&source); } out: return ret; @@ -1378,6 +1485,37 @@ static bool can_offline_normal(struct zone *zone, unsigned long nr_pages) } #endif /* CONFIG_MOVABLE_NODE */ +static int __init cmdline_parse_movable_node(char *p) +{ +#ifdef CONFIG_MOVABLE_NODE + /* + * Memory used by the kernel cannot be hot-removed because Linux + * cannot migrate the kernel pages. When memory hotplug is + * enabled, we should prevent memblock from allocating memory + * for the kernel. + * + * ACPI SRAT records all hotpluggable memory ranges. But before + * SRAT is parsed, we don't know about it. + * + * The kernel image is loaded into memory at very early time. We + * cannot prevent this anyway. So on NUMA system, we set any + * node the kernel resides in as un-hotpluggable. + * + * Since on modern servers, one node could have double-digit + * gigabytes memory, we can assume the memory around the kernel + * image is also un-hotpluggable. So before SRAT is parsed, just + * allocate memory near the kernel image to try the best to keep + * the kernel away from hotpluggable memory. + */ + memblock_set_bottom_up(true); + movable_node_enabled = true; +#else + pr_warn("movable_node option not supported\n"); +#endif + return 0; +} +early_param("movable_node", cmdline_parse_movable_node); + /* check which state of node_states will be changed when offline memory */ static void node_states_check_changes_offline(unsigned long nr_pages, struct zone *zone, struct memory_notify *arg) @@ -1475,10 +1613,10 @@ static int __ref __offline_pages(unsigned long start_pfn, unsigned long pfn, nr_pages, expire; long offlined_pages; int ret, drain, retry_max, node; + unsigned long flags; struct zone *zone; struct memory_notify arg; - BUG_ON(start_pfn >= end_pfn); /* at least, alignment against pageblock is necessary */ if (!IS_ALIGNED(start_pfn, pageblock_nr_pages)) return -EINVAL; @@ -1489,7 +1627,7 @@ static int __ref __offline_pages(unsigned long start_pfn, if (!test_pages_in_a_zone(start_pfn, end_pfn)) return -EINVAL; - lock_memory_hotplug(); + mem_hotplug_begin(); zone = page_zone(pfn_to_page(start_pfn)); node = zone_to_nid(zone); @@ -1533,8 +1671,8 @@ repeat: drain_all_pages(); } - pfn = scan_lru_pages(start_pfn, end_pfn); - if (pfn) { /* We have page on LRU */ + pfn = scan_movable_pages(start_pfn, end_pfn); + if (pfn) { /* We have movable pages */ ret = do_migrate_range(pfn, end_pfn); if (!ret) { drain = 1; @@ -1553,6 +1691,11 @@ repeat: yield(); /* drain pcp pages, this is synchronous. */ drain_all_pages(); + /* + * dissolve free hugepages in the memory block before doing offlining + * actually in order to make hugetlbfs's object counting consistent. + */ + dissolve_free_huge_pages(start_pfn, end_pfn); /* check again */ offlined_pages = check_pages_isolated(start_pfn, end_pfn); if (offlined_pages < 0) { @@ -1566,10 +1709,12 @@ repeat: /* reset pagetype flags and makes migrate type to be MOVABLE */ undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE); /* removal success */ - zone->managed_pages -= offlined_pages; + adjust_managed_page_count(pfn_to_page(start_pfn), -offlined_pages); zone->present_pages -= offlined_pages; + + pgdat_resize_lock(zone->zone_pgdat, &flags); zone->zone_pgdat->node_present_pages -= offlined_pages; - totalram_pages -= offlined_pages; + pgdat_resize_unlock(zone->zone_pgdat, &flags); init_per_zone_wmark_min(); @@ -1589,7 +1734,7 @@ repeat: writeback_set_ratelimit(); memory_notify(MEM_OFFLINE, &arg); - unlock_memory_hotplug(); + mem_hotplug_done(); return 0; failed_removal: @@ -1601,7 +1746,7 @@ failed_removal: undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE); out: - unlock_memory_hotplug(); + mem_hotplug_done(); return ret; } @@ -1609,11 +1754,12 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages) { return __offline_pages(start_pfn, start_pfn + nr_pages, 120 * HZ); } +#endif /* CONFIG_MEMORY_HOTREMOVE */ /** * walk_memory_range - walks through all mem sections in [start_pfn, end_pfn) * @start_pfn: start pfn of the memory range - * @end_pfn: end pft of the memory range + * @end_pfn: end pfn of the memory range * @arg: argument passed to func * @func: callback for each memory section walked * @@ -1622,7 +1768,7 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages) * * Returns the return value of func. */ -static int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn, +int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn, void *arg, int (*func)(struct memory_block *, void *)) { struct memory_block *mem = NULL; @@ -1659,40 +1805,26 @@ static int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn, return 0; } -/** - * offline_memory_block_cb - callback function for offlining memory block - * @mem: the memory block to be offlined - * @arg: buffer to hold error msg - * - * Always return 0, and put the error msg in arg if any. - */ -static int offline_memory_block_cb(struct memory_block *mem, void *arg) -{ - int *ret = arg; - int error = offline_memory_block(mem); - - if (error != 0 && *ret == 0) - *ret = error; - - return 0; -} - -static int is_memblock_offlined_cb(struct memory_block *mem, void *arg) +#ifdef CONFIG_MEMORY_HOTREMOVE +static int check_memblock_offlined_cb(struct memory_block *mem, void *arg) { int ret = !is_memblock_offlined(mem); - if (unlikely(ret)) + if (unlikely(ret)) { + phys_addr_t beginpa, endpa; + + beginpa = PFN_PHYS(section_nr_to_pfn(mem->start_section_nr)); + endpa = PFN_PHYS(section_nr_to_pfn(mem->end_section_nr + 1))-1; pr_warn("removing memory fails, because memory " - "[%#010llx-%#010llx] is onlined\n", - PFN_PHYS(section_nr_to_pfn(mem->start_section_nr)), - PFN_PHYS(section_nr_to_pfn(mem->end_section_nr + 1))-1); + "[%pa-%pa] is onlined\n", + &beginpa, &endpa); + } return ret; } -static int check_cpu_on_node(void *data) +static int check_cpu_on_node(pg_data_t *pgdat) { - struct pglist_data *pgdat = data; int cpu; for_each_present_cpu(cpu) { @@ -1707,10 +1839,9 @@ static int check_cpu_on_node(void *data) return 0; } -static void unmap_cpu_on_node(void *data) +static void unmap_cpu_on_node(pg_data_t *pgdat) { #ifdef CONFIG_ACPI_NUMA - struct pglist_data *pgdat = data; int cpu; for_each_possible_cpu(cpu) @@ -1719,10 +1850,11 @@ static void unmap_cpu_on_node(void *data) #endif } -static int check_and_unmap_cpu_on_node(void *data) +static int check_and_unmap_cpu_on_node(pg_data_t *pgdat) { - int ret = check_cpu_on_node(data); + int ret; + ret = check_cpu_on_node(pgdat); if (ret) return ret; @@ -1731,11 +1863,18 @@ static int check_and_unmap_cpu_on_node(void *data) * the cpu_to_node() now. */ - unmap_cpu_on_node(data); + unmap_cpu_on_node(pgdat); return 0; } -/* offline the node if all memory sections of this node are removed */ +/** + * try_offline_node + * + * Offline a node if all memory sections and cpus of the node are removed. + * + * NOTE: The caller must call lock_device_hotplug() to serialize hotplug + * and online/offline operations before this call. + */ void try_offline_node(int nid) { pg_data_t *pgdat = NODE_DATA(nid); @@ -1761,7 +1900,7 @@ void try_offline_node(int nid) return; } - if (stop_machine(check_and_unmap_cpu_on_node, pgdat, NULL)) + if (check_and_unmap_cpu_on_node(pgdat)) return; /* @@ -1779,7 +1918,11 @@ void try_offline_node(int nid) for (i = 0; i < MAX_NR_ZONES; i++) { struct zone *zone = pgdat->node_zones + i; - if (zone->wait_table) + /* + * wait_table may be allocated from boot memory, + * here only free if it's allocated by vmalloc. + */ + if (is_vmalloc_addr(zone->wait_table)) vfree(zone->wait_table); } @@ -1794,55 +1937,30 @@ void try_offline_node(int nid) } EXPORT_SYMBOL(try_offline_node); -int __ref remove_memory(int nid, u64 start, u64 size) +/** + * remove_memory + * + * NOTE: The caller must call lock_device_hotplug() to serialize hotplug + * and online/offline operations before this call, as required by + * try_offline_node(). + */ +void __ref remove_memory(int nid, u64 start, u64 size) { - unsigned long start_pfn, end_pfn; - int ret = 0; - int retry = 1; - - start_pfn = PFN_DOWN(start); - end_pfn = start_pfn + PFN_DOWN(size); - - /* - * When CONFIG_MEMCG is on, one memory block may be used by other - * blocks to store page cgroup when onlining pages. But we don't know - * in what order pages are onlined. So we iterate twice to offline - * memory: - * 1st iterate: offline every non primary memory block. - * 2nd iterate: offline primary (i.e. first added) memory block. - */ -repeat: - walk_memory_range(start_pfn, end_pfn, &ret, - offline_memory_block_cb); - if (ret) { - if (!retry) - return ret; + int ret; - retry = 0; - ret = 0; - goto repeat; - } + BUG_ON(check_hotplug_memory_range(start, size)); - lock_memory_hotplug(); + mem_hotplug_begin(); /* - * we have offlined all memory blocks like this: - * 1. lock memory hotplug - * 2. offline a memory block - * 3. unlock memory hotplug - * - * repeat step1-3 to offline the memory block. All memory blocks - * must be offlined before removing memory. But we don't hold the - * lock in the whole operation. So we should check whether all - * memory blocks are offlined. + * All memory blocks must be offlined before removing memory. Check + * whether all memory blocks in question are offline and trigger a BUG() + * if this is not the case. */ - - ret = walk_memory_range(start_pfn, end_pfn, NULL, - is_memblock_offlined_cb); - if (ret) { - unlock_memory_hotplug(); - return ret; - } + ret = walk_memory_range(PFN_DOWN(start), PFN_UP(start + size - 1), NULL, + check_memblock_offlined_cb); + if (ret) + BUG(); /* remove memmap entry */ firmware_map_remove(start, start + size, "System RAM"); @@ -1851,18 +1969,7 @@ repeat: try_offline_node(nid); - unlock_memory_hotplug(); - - return 0; + mem_hotplug_done(); } -#else -int offline_pages(unsigned long start_pfn, unsigned long nr_pages) -{ - return -EINVAL; -} -int remove_memory(int nid, u64 start, u64 size) -{ - return -EINVAL; -} -#endif /* CONFIG_MEMORY_HOTREMOVE */ EXPORT_SYMBOL_GPL(remove_memory); +#endif /* CONFIG_MEMORY_HOTREMOVE */ |