| /* |
| * linux/mm/memory_hotplug.c |
| * |
| * Copyright (C) |
| */ |
| |
| #include <linux/stddef.h> |
| #include <linux/mm.h> |
| #include <linux/swap.h> |
| #include <linux/interrupt.h> |
| #include <linux/pagemap.h> |
| #include <linux/bootmem.h> |
| #include <linux/compiler.h> |
| #include <linux/module.h> |
| #include <linux/pagevec.h> |
| #include <linux/writeback.h> |
| #include <linux/slab.h> |
| #include <linux/sysctl.h> |
| #include <linux/cpu.h> |
| #include <linux/memory.h> |
| #include <linux/memory_hotplug.h> |
| #include <linux/highmem.h> |
| #include <linux/vmalloc.h> |
| #include <linux/ioport.h> |
| #include <linux/cpuset.h> |
| #include <linux/delay.h> |
| #include <linux/migrate.h> |
| #include <linux/page-isolation.h> |
| |
| #include <asm/tlbflush.h> |
| |
| /* add this memory to iomem resource */ |
| static struct resource *register_memory_resource(u64 start, u64 size) |
| { |
| struct resource *res; |
| res = kzalloc(sizeof(struct resource), GFP_KERNEL); |
| BUG_ON(!res); |
| |
| res->name = "System RAM"; |
| res->start = start; |
| res->end = start + size - 1; |
| res->flags = IORESOURCE_MEM; |
| if (request_resource(&iomem_resource, res) < 0) { |
| printk("System RAM resource %llx - %llx cannot be added\n", |
| (unsigned long long)res->start, (unsigned long long)res->end); |
| kfree(res); |
| res = NULL; |
| } |
| return res; |
| } |
| |
| static void release_memory_resource(struct resource *res) |
| { |
| if (!res) |
| return; |
| release_resource(res); |
| kfree(res); |
| return; |
| } |
| |
| |
| #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE |
| static int __add_zone(struct zone *zone, unsigned long phys_start_pfn) |
| { |
| struct pglist_data *pgdat = zone->zone_pgdat; |
| int nr_pages = PAGES_PER_SECTION; |
| int nid = pgdat->node_id; |
| int zone_type; |
| |
| zone_type = zone - pgdat->node_zones; |
| if (!zone->wait_table) { |
| int ret = 0; |
| ret = init_currently_empty_zone(zone, phys_start_pfn, |
| nr_pages, MEMMAP_HOTPLUG); |
| if (ret < 0) |
| return ret; |
| } |
| memmap_init_zone(nr_pages, nid, zone_type, |
| phys_start_pfn, MEMMAP_HOTPLUG); |
| return 0; |
| } |
| |
| static int __add_section(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); |
| |
| if (ret < 0) |
| return ret; |
| |
| ret = __add_zone(zone, phys_start_pfn); |
| |
| if (ret < 0) |
| return ret; |
| |
| return register_new_memory(__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 __add_pages(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(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); |
| |
| static void grow_zone_span(struct zone *zone, |
| unsigned long start_pfn, unsigned long end_pfn) |
| { |
| unsigned long old_zone_end_pfn; |
| |
| zone_span_writelock(zone); |
| |
| old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages; |
| if (start_pfn < zone->zone_start_pfn) |
| zone->zone_start_pfn = start_pfn; |
| |
| zone->spanned_pages = max(old_zone_end_pfn, end_pfn) - |
| zone->zone_start_pfn; |
| |
| zone_span_writeunlock(zone); |
| } |
| |
| 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; |
| |
| if (start_pfn < pgdat->node_start_pfn) |
| pgdat->node_start_pfn = start_pfn; |
| |
| pgdat->node_spanned_pages = max(old_pgdat_end_pfn, end_pfn) - |
| pgdat->node_start_pfn; |
| } |
| |
| static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages, |
| void *arg) |
| { |
| unsigned long i; |
| unsigned long onlined_pages = *(unsigned long *)arg; |
| struct page *page; |
| if (PageReserved(pfn_to_page(start_pfn))) |
| for (i = 0; i < nr_pages; i++) { |
| page = pfn_to_page(start_pfn + i); |
| online_page(page); |
| onlined_pages++; |
| } |
| *(unsigned long *)arg = onlined_pages; |
| return 0; |
| } |
| |
| |
| int online_pages(unsigned long pfn, unsigned long nr_pages) |
| { |
| unsigned long flags; |
| unsigned long onlined_pages = 0; |
| struct zone *zone; |
| int need_zonelists_rebuild = 0; |
| int nid; |
| int ret; |
| struct memory_notify arg; |
| |
| arg.start_pfn = pfn; |
| arg.nr_pages = nr_pages; |
| arg.status_change_nid = -1; |
| |
| nid = page_to_nid(pfn_to_page(pfn)); |
| if (node_present_pages(nid) == 0) |
| arg.status_change_nid = nid; |
| |
| ret = memory_notify(MEM_GOING_ONLINE, &arg); |
| ret = notifier_to_errno(ret); |
| if (ret) { |
| memory_notify(MEM_CANCEL_ONLINE, &arg); |
| return ret; |
| } |
| /* |
| * This doesn't need a lock to do pfn_to_page(). |
| * The section can't be removed here because of the |
| * memory_block->state_sem. |
| */ |
| zone = page_zone(pfn_to_page(pfn)); |
| pgdat_resize_lock(zone->zone_pgdat, &flags); |
| grow_zone_span(zone, pfn, pfn + nr_pages); |
| grow_pgdat_span(zone->zone_pgdat, pfn, pfn + nr_pages); |
| pgdat_resize_unlock(zone->zone_pgdat, &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. |
| */ |
| if (!populated_zone(zone)) |
| need_zonelists_rebuild = 1; |
| |
| walk_memory_resource(pfn, nr_pages, &onlined_pages, |
| online_pages_range); |
| zone->present_pages += onlined_pages; |
| zone->zone_pgdat->node_present_pages += onlined_pages; |
| |
| setup_per_zone_pages_min(); |
| if (onlined_pages) { |
| kswapd_run(zone_to_nid(zone)); |
| node_set_state(zone_to_nid(zone), N_HIGH_MEMORY); |
| } |
| |
| if (need_zonelists_rebuild) |
| build_all_zonelists(); |
| vm_total_pages = nr_free_pagecache_pages(); |
| writeback_set_ratelimit(); |
| |
| if (onlined_pages) |
| memory_notify(MEM_ONLINE, &arg); |
| |
| return 0; |
| } |
| #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ |
| |
| static pg_data_t *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; |
| |
| pgdat = arch_alloc_nodedata(nid); |
| if (!pgdat) |
| return NULL; |
| |
| arch_refresh_nodedata(nid, pgdat); |
| |
| /* we can use NODE_DATA(nid) from here */ |
| |
| /* init node's zones as empty zones, we don't have any present pages.*/ |
| free_area_init_node(nid, pgdat, zones_size, start_pfn, zholes_size); |
| |
| return pgdat; |
| } |
| |
| static void rollback_node_hotadd(int nid, pg_data_t *pgdat) |
| { |
| arch_refresh_nodedata(nid, NULL); |
| arch_free_nodedata(pgdat); |
| return; |
| } |
| |
| |
| int add_memory(int nid, u64 start, u64 size) |
| { |
| pg_data_t *pgdat = NULL; |
| int new_pgdat = 0; |
| struct resource *res; |
| int ret; |
| |
| res = register_memory_resource(start, size); |
| if (!res) |
| return -EEXIST; |
| |
| if (!node_online(nid)) { |
| pgdat = hotadd_new_pgdat(nid, start); |
| if (!pgdat) |
| return -ENOMEM; |
| new_pgdat = 1; |
| } |
| |
| /* call arch's memory hotadd */ |
| ret = arch_add_memory(nid, start, size); |
| |
| if (ret < 0) |
| goto error; |
| |
| /* we online node here. we can't roll back from here. */ |
| node_set_online(nid); |
| |
| cpuset_track_online_nodes(); |
| |
| if (new_pgdat) { |
| ret = register_one_node(nid); |
| /* |
| * If sysfs file of new node can't create, cpu on the node |
| * can't be hot-added. There is no rollback way now. |
| * So, check by BUG_ON() to catch it reluctantly.. |
| */ |
| BUG_ON(ret); |
| } |
| |
| return ret; |
| error: |
| /* rollback pgdat allocation and others */ |
| if (new_pgdat) |
| rollback_node_hotadd(nid, pgdat); |
| if (res) |
| release_memory_resource(res); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(add_memory); |
| |
| #ifdef CONFIG_MEMORY_HOTREMOVE |
| /* |
| * Confirm all pages in a range [start, end) is belongs to the same zone. |
| */ |
| static int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn) |
| { |
| unsigned long pfn; |
| struct zone *zone = NULL; |
| struct page *page; |
| int i; |
| for (pfn = start_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) |
| continue; |
| page = pfn_to_page(pfn + i); |
| if (zone && page_zone(page) != zone) |
| return 0; |
| zone = page_zone(page); |
| } |
| return 1; |
| } |
| |
| /* |
| * Scanning pfn is much easier than scanning lru list. |
| * Scan pfn from start to end and Find LRU page. |
| */ |
| int scan_lru_pages(unsigned long start, unsigned long end) |
| { |
| unsigned long pfn; |
| struct page *page; |
| for (pfn = start; pfn < end; pfn++) { |
| if (pfn_valid(pfn)) { |
| page = pfn_to_page(pfn); |
| if (PageLRU(page)) |
| return pfn; |
| } |
| } |
| return 0; |
| } |
| |
| static struct page * |
| hotremove_migrate_alloc(struct page *page, |
| unsigned long private, |
| int **x) |
| { |
| /* This should be improoooooved!! */ |
| return alloc_page(GFP_HIGHUSER_PAGECACHE); |
| } |
| |
| |
| #define NR_OFFLINE_AT_ONCE_PAGES (256) |
| static int |
| do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) |
| { |
| unsigned long pfn; |
| struct page *page; |
| int move_pages = NR_OFFLINE_AT_ONCE_PAGES; |
| int not_managed = 0; |
| int ret = 0; |
| LIST_HEAD(source); |
| |
| for (pfn = start_pfn; pfn < end_pfn && move_pages > 0; pfn++) { |
| if (!pfn_valid(pfn)) |
| continue; |
| page = pfn_to_page(pfn); |
| if (!page_count(page)) |
| continue; |
| /* |
| * We can skip free pages. And we can only deal with pages on |
| * LRU. |
| */ |
| ret = isolate_lru_page(page, &source); |
| if (!ret) { /* Success */ |
| move_pages--; |
| } else { |
| /* Becasue we don't have big zone->lock. we should |
| check this again here. */ |
| if (page_count(page)) |
| not_managed++; |
| #ifdef CONFIG_DEBUG_VM |
| printk(KERN_INFO "removing from LRU failed" |
| " %lx/%d/%lx\n", |
| pfn, page_count(page), page->flags); |
| #endif |
| } |
| } |
| ret = -EBUSY; |
| if (not_managed) { |
| if (!list_empty(&source)) |
| putback_lru_pages(&source); |
| goto out; |
| } |
| ret = 0; |
| if (list_empty(&source)) |
| goto out; |
| /* this function returns # of failed pages */ |
| ret = migrate_pages(&source, hotremove_migrate_alloc, 0); |
| |
| out: |
| return ret; |
| } |
| |
| /* |
| * remove from free_area[] and mark all as Reserved. |
| */ |
| static int |
| offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages, |
| void *data) |
| { |
| __offline_isolated_pages(start, start + nr_pages); |
| return 0; |
| } |
| |
| static void |
| offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) |
| { |
| walk_memory_resource(start_pfn, end_pfn - start_pfn, NULL, |
| offline_isolated_pages_cb); |
| } |
| |
| /* |
| * 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) |
| { |
| int ret; |
| long offlined = *(long *)data; |
| ret = test_pages_isolated(start_pfn, start_pfn + nr_pages); |
| offlined = nr_pages; |
| if (!ret) |
| *(long *)data += offlined; |
| return ret; |
| } |
| |
| static long |
| check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn) |
| { |
| long offlined = 0; |
| int ret; |
| |
| ret = walk_memory_resource(start_pfn, end_pfn - start_pfn, &offlined, |
| check_pages_isolated_cb); |
| if (ret < 0) |
| offlined = (long)ret; |
| return offlined; |
| } |
| |
| extern void drain_all_local_pages(void); |
| |
| int offline_pages(unsigned long start_pfn, |
| unsigned long end_pfn, unsigned long timeout) |
| { |
| unsigned long pfn, nr_pages, expire; |
| long offlined_pages; |
| int ret, drain, retry_max, node; |
| 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; |
| if (!IS_ALIGNED(end_pfn, pageblock_nr_pages)) |
| return -EINVAL; |
| /* This makes hotplug much easier...and readable. |
| we assume this for now. .*/ |
| if (!test_pages_in_a_zone(start_pfn, end_pfn)) |
| return -EINVAL; |
| |
| zone = page_zone(pfn_to_page(start_pfn)); |
| node = zone_to_nid(zone); |
| nr_pages = end_pfn - start_pfn; |
| |
| /* set above range as isolated */ |
| ret = start_isolate_page_range(start_pfn, end_pfn); |
| if (ret) |
| return ret; |
| |
| arg.start_pfn = start_pfn; |
| arg.nr_pages = nr_pages; |
| arg.status_change_nid = -1; |
| if (nr_pages >= node_present_pages(node)) |
| arg.status_change_nid = node; |
| |
| ret = memory_notify(MEM_GOING_OFFLINE, &arg); |
| ret = notifier_to_errno(ret); |
| if (ret) |
| goto failed_removal; |
| |
| pfn = start_pfn; |
| expire = jiffies + timeout; |
| drain = 0; |
| retry_max = 5; |
| repeat: |
| /* start memory hot removal */ |
| ret = -EAGAIN; |
| if (time_after(jiffies, expire)) |
| goto failed_removal; |
| ret = -EINTR; |
| if (signal_pending(current)) |
| goto failed_removal; |
| ret = 0; |
| if (drain) { |
| lru_add_drain_all(); |
| flush_scheduled_work(); |
| cond_resched(); |
| drain_all_local_pages(); |
| } |
| |
| pfn = scan_lru_pages(start_pfn, end_pfn); |
| if (pfn) { /* We have page on LRU */ |
| ret = do_migrate_range(pfn, end_pfn); |
| if (!ret) { |
| drain = 1; |
| goto repeat; |
| } else { |
| if (ret < 0) |
| if (--retry_max == 0) |
| goto failed_removal; |
| yield(); |
| drain = 1; |
| goto repeat; |
| } |
| } |
| /* drain all zone's lru pagevec, this is asyncronous... */ |
| lru_add_drain_all(); |
| flush_scheduled_work(); |
| yield(); |
| /* drain pcp pages , this is synchrouns. */ |
| drain_all_local_pages(); |
| /* check again */ |
| offlined_pages = check_pages_isolated(start_pfn, end_pfn); |
| if (offlined_pages < 0) { |
| ret = -EBUSY; |
| goto failed_removal; |
| } |
| printk(KERN_INFO "Offlined Pages %ld\n", offlined_pages); |
| /* Ok, all of our target is islaoted. |
| We cannot do rollback at this point. */ |
| offline_isolated_pages(start_pfn, end_pfn); |
| /* reset pagetype flags and makes migrate type to be MOVABLE */ |
| undo_isolate_page_range(start_pfn, end_pfn); |
| /* removal success */ |
| zone->present_pages -= offlined_pages; |
| zone->zone_pgdat->node_present_pages -= offlined_pages; |
| totalram_pages -= offlined_pages; |
| num_physpages -= offlined_pages; |
| |
| vm_total_pages = nr_free_pagecache_pages(); |
| writeback_set_ratelimit(); |
| |
| memory_notify(MEM_OFFLINE, &arg); |
| return 0; |
| |
| failed_removal: |
| printk(KERN_INFO "memory offlining %lx to %lx failed\n", |
| start_pfn, end_pfn); |
| memory_notify(MEM_CANCEL_OFFLINE, &arg); |
| /* pushback to free area */ |
| undo_isolate_page_range(start_pfn, end_pfn); |
| |
| return ret; |
| } |
| #else |
| int remove_memory(u64 start, u64 size) |
| { |
| return -EINVAL; |
| } |
| EXPORT_SYMBOL_GPL(remove_memory); |
| #endif /* CONFIG_MEMORY_HOTREMOVE */ |