diff options
Diffstat (limited to 'mm/memory_hotplug.c')
| -rw-r--r-- | mm/memory_hotplug.c | 475 |
1 files changed, 219 insertions, 256 deletions
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index c73f09913165..0a54ffac8c68 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -49,8 +49,6 @@ * and restore_online_page_callback() for generic callback restore. */ -static void generic_online_page(struct page *page, unsigned int order); - static online_page_callback_t online_page_callback = generic_online_page; static DEFINE_MUTEX(online_page_callback_lock); @@ -278,6 +276,22 @@ static int check_pfn_span(unsigned long pfn, unsigned long nr_pages, return 0; } +static int check_hotplug_memory_addressable(unsigned long pfn, + unsigned long nr_pages) +{ + const u64 max_addr = PFN_PHYS(pfn + nr_pages) - 1; + + 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; + } + + return 0; +} + /* * Reasonably generic function for adding memory. It is * expected that archs that support memory hotplug will @@ -291,6 +305,10 @@ int __ref __add_pages(int nid, unsigned long pfn, unsigned long nr_pages, unsigned long nr, start_sec, end_sec; struct vmem_altmap *altmap = restrictions->altmap; + err = check_hotplug_memory_addressable(pfn, nr_pages); + if (err) + return err; + if (altmap) { /* * Validate altmap is within bounds of the total request @@ -331,13 +349,13 @@ static unsigned long find_smallest_section_pfn(int nid, struct zone *zone, unsigned long end_pfn) { for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SUBSECTION) { - if (unlikely(!pfn_valid(start_pfn))) + if (unlikely(!pfn_to_online_page(start_pfn))) continue; if (unlikely(pfn_to_nid(start_pfn) != nid)) continue; - if (zone && zone != page_zone(pfn_to_page(start_pfn))) + if (zone != page_zone(pfn_to_page(start_pfn))) continue; return start_pfn; @@ -356,13 +374,13 @@ static unsigned long find_biggest_section_pfn(int nid, struct zone *zone, /* pfn is the end pfn of a memory section. */ pfn = end_pfn - 1; for (; pfn >= start_pfn; pfn -= PAGES_PER_SUBSECTION) { - if (unlikely(!pfn_valid(pfn))) + if (unlikely(!pfn_to_online_page(pfn))) continue; if (unlikely(pfn_to_nid(pfn) != nid)) continue; - if (zone && zone != page_zone(pfn_to_page(pfn))) + if (zone != page_zone(pfn_to_page(pfn))) continue; return pfn; @@ -374,14 +392,11 @@ static unsigned long 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 z = zone_end_pfn(zone); /* zone_end_pfn namespace clash */ - unsigned long zone_end_pfn = z; unsigned long pfn; int nid = zone_to_nid(zone); zone_span_writelock(zone); - if (zone_start_pfn == start_pfn) { + if (zone->zone_start_pfn == start_pfn) { /* * If the section is smallest section in the zone, it need * shrink zone->zone_start_pfn and zone->zone_spanned_pages. @@ -389,144 +404,106 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, * for shrinking zone. */ pfn = find_smallest_section_pfn(nid, zone, end_pfn, - zone_end_pfn); + zone_end_pfn(zone)); if (pfn) { + zone->spanned_pages = zone_end_pfn(zone) - pfn; zone->zone_start_pfn = pfn; - zone->spanned_pages = zone_end_pfn - pfn; + } else { + zone->zone_start_pfn = 0; + zone->spanned_pages = 0; } - } else if (zone_end_pfn == end_pfn) { + } else if (zone_end_pfn(zone) == end_pfn) { /* * If the section is biggest section in the zone, it need * shrink zone->spanned_pages. * In this case, we find second biggest valid mem_section for * shrinking zone. */ - pfn = find_biggest_section_pfn(nid, zone, zone_start_pfn, + pfn = find_biggest_section_pfn(nid, zone, zone->zone_start_pfn, start_pfn); if (pfn) - zone->spanned_pages = pfn - zone_start_pfn + 1; - } - - /* - * The section is not biggest or smallest mem_section in the zone, it - * only creates a hole in the zone. So in this case, we need not - * change the zone. But perhaps, the zone has only hole data. Thus - * it check the zone has only hole or not. - */ - pfn = zone_start_pfn; - for (; pfn < zone_end_pfn; pfn += PAGES_PER_SUBSECTION) { - if (unlikely(!pfn_valid(pfn))) - continue; - - if (page_zone(pfn_to_page(pfn)) != zone) - continue; - - /* Skip range to be removed */ - if (pfn >= start_pfn && pfn < end_pfn) - continue; - - /* If we find valid section, we have nothing to do */ - zone_span_writeunlock(zone); - return; + zone->spanned_pages = pfn - zone->zone_start_pfn + 1; + else { + zone->zone_start_pfn = 0; + zone->spanned_pages = 0; + } } - - /* The zone has no valid section */ - zone->zone_start_pfn = 0; - zone->spanned_pages = 0; zone_span_writeunlock(zone); } -static void shrink_pgdat_span(struct pglist_data *pgdat, - unsigned long start_pfn, unsigned long end_pfn) +static void update_pgdat_span(struct pglist_data *pgdat) { - 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; - int nid = pgdat->node_id; + unsigned long node_start_pfn = 0, node_end_pfn = 0; + struct zone *zone; - if (pgdat_start_pfn == start_pfn) { - /* - * If the section is smallest section in the pgdat, it need - * shrink pgdat->node_start_pfn and pgdat->node_spanned_pages. - * In this case, we find second smallest valid mem_section - * for shrinking zone. - */ - pfn = find_smallest_section_pfn(nid, NULL, end_pfn, - pgdat_end_pfn); - if (pfn) { - pgdat->node_start_pfn = pfn; - pgdat->node_spanned_pages = pgdat_end_pfn - pfn; - } - } else if (pgdat_end_pfn == end_pfn) { - /* - * If the section is biggest section in the pgdat, it need - * shrink pgdat->node_spanned_pages. - * In this case, we find second biggest valid mem_section for - * shrinking zone. - */ - pfn = find_biggest_section_pfn(nid, NULL, pgdat_start_pfn, - start_pfn); - if (pfn) - pgdat->node_spanned_pages = pfn - pgdat_start_pfn + 1; - } + 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; - /* - * If the section is not biggest or smallest mem_section in the pgdat, - * it only creates a hole in the pgdat. So in this case, we need not - * change the pgdat. - * But perhaps, the pgdat has only hole data. Thus it check the pgdat - * has only hole or not. - */ - pfn = pgdat_start_pfn; - for (; pfn < pgdat_end_pfn; pfn += PAGES_PER_SUBSECTION) { - if (unlikely(!pfn_valid(pfn))) - continue; - - if (pfn_to_nid(pfn) != nid) + /* No need to lock the zones, they can't change. */ + if (!zone->spanned_pages) continue; - - /* Skip range to be removed */ - if (pfn >= start_pfn && pfn < end_pfn) + if (!node_end_pfn) { + node_start_pfn = zone->zone_start_pfn; + node_end_pfn = zone_end_pfn; continue; + } - /* If we find valid section, we have nothing to do */ - return; + if (zone_end_pfn > node_end_pfn) + node_end_pfn = zone_end_pfn; + if (zone->zone_start_pfn < node_start_pfn) + node_start_pfn = zone->zone_start_pfn; } - /* The pgdat has no valid section */ - pgdat->node_start_pfn = 0; - pgdat->node_spanned_pages = 0; + pgdat->node_start_pfn = node_start_pfn; + pgdat->node_spanned_pages = node_end_pfn - node_start_pfn; } -static void __remove_zone(struct zone *zone, unsigned long start_pfn, - unsigned long nr_pages) +void __ref remove_pfn_range_from_zone(struct zone *zone, + unsigned long start_pfn, + unsigned long nr_pages) { struct pglist_data *pgdat = zone->zone_pgdat; unsigned long flags; + /* Poison struct pages because they are now uninitialized again. */ + page_init_poison(pfn_to_page(start_pfn), sizeof(struct page) * 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) + return; +#endif + + clear_zone_contiguous(zone); + pgdat_resize_lock(zone->zone_pgdat, &flags); shrink_zone_span(zone, start_pfn, start_pfn + nr_pages); - shrink_pgdat_span(pgdat, start_pfn, start_pfn + nr_pages); + update_pgdat_span(pgdat); pgdat_resize_unlock(zone->zone_pgdat, &flags); + + set_zone_contiguous(zone); } -static void __remove_section(struct zone *zone, unsigned long pfn, - unsigned long nr_pages, unsigned long map_offset, - struct vmem_altmap *altmap) +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)); if (WARN_ON_ONCE(!valid_section(ms))) return; - __remove_zone(zone, pfn, nr_pages); sparse_remove_section(ms, pfn, nr_pages, map_offset, altmap); } /** - * __remove_pages() - remove sections of pages from a zone - * @zone: zone from which pages need to be removed + * __remove_pages() - remove sections of pages * @pfn: starting pageframe (must be aligned to start of a section) * @nr_pages: number of pages to remove (must be multiple of section size) * @altmap: alternative device page map or %NULL if default memmap is used @@ -536,34 +513,25 @@ static void __remove_section(struct zone *zone, unsigned long pfn, * sure that pages are marked reserved and zones are adjust properly by * calling offline_pages(). */ -void __remove_pages(struct zone *zone, unsigned long pfn, - unsigned long nr_pages, struct vmem_altmap *altmap) +void __remove_pages(unsigned long pfn, unsigned long nr_pages, + struct vmem_altmap *altmap) { + const unsigned long end_pfn = pfn + nr_pages; + unsigned long cur_nr_pages; unsigned long map_offset = 0; - unsigned long nr, start_sec, end_sec; map_offset = vmem_altmap_offset(altmap); - clear_zone_contiguous(zone); - if (check_pfn_span(pfn, nr_pages, "remove")) return; - 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; - + for (; pfn < end_pfn; pfn += cur_nr_pages) { cond_resched(); - pfns = min(nr_pages, PAGES_PER_SECTION - - (pfn & ~PAGE_SECTION_MASK)); - __remove_section(zone, pfn, pfns, map_offset, altmap); - pfn += pfns; - nr_pages -= pfns; + /* Select all remaining pages up to the next section boundary */ + cur_nr_pages = min(end_pfn - pfn, -(pfn | PAGE_SECTION_MASK)); + __remove_section(pfn, cur_nr_pages, map_offset, altmap); map_offset = 0; } - - set_zone_contiguous(zone); } int set_online_page_callback(online_page_callback_t callback) @@ -604,24 +572,7 @@ int restore_online_page_callback(online_page_callback_t callback) } EXPORT_SYMBOL_GPL(restore_online_page_callback); -void __online_page_set_limits(struct page *page) -{ -} -EXPORT_SYMBOL_GPL(__online_page_set_limits); - -void __online_page_increment_counters(struct page *page) -{ - adjust_managed_page_count(page, 1); -} -EXPORT_SYMBOL_GPL(__online_page_increment_counters); - -void __online_page_free(struct page *page) -{ - __free_reserved_page(page); -} -EXPORT_SYMBOL_GPL(__online_page_free); - -static void generic_online_page(struct page *page, unsigned int order) +void generic_online_page(struct page *page, unsigned int order) { kernel_map_pages(page, 1 << order, 1); __free_pages_core(page, order); @@ -631,34 +582,32 @@ static void generic_online_page(struct page *page, unsigned int order) totalhigh_pages_add(1UL << order); #endif } - -static int online_pages_blocks(unsigned long start, unsigned long nr_pages) -{ - unsigned long end = start + nr_pages; - int order, onlined_pages = 0; - - while (start < end) { - order = min(MAX_ORDER - 1, - get_order(PFN_PHYS(end) - PFN_PHYS(start))); - (*online_page_callback)(pfn_to_page(start), order); - - onlined_pages += (1UL << order); - start += (1UL << order); - } - return onlined_pages; -} +EXPORT_SYMBOL_GPL(generic_online_page); static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages, void *arg) { - unsigned long onlined_pages = *(unsigned long *)arg; + const unsigned long end_pfn = start_pfn + nr_pages; + unsigned long pfn; + int order; - if (PageReserved(pfn_to_page(start_pfn))) - onlined_pages += online_pages_blocks(start_pfn, nr_pages); + /* + * 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"). + */ + 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; + (*online_page_callback)(pfn_to_page(pfn), order); + } - online_mem_sections(start_pfn, start_pfn + nr_pages); + /* mark all involved sections as online */ + online_mem_sections(start_pfn, end_pfn); - *(unsigned long *)arg = onlined_pages; + *(unsigned long *)arg += nr_pages; return 0; } @@ -714,8 +663,13 @@ static void __meminit resize_pgdat_range(struct pglist_data *pgdat, unsigned lon pgdat->node_start_pfn = start_pfn; pgdat->node_spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - pgdat->node_start_pfn; -} +} +/* + * 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. + */ void __ref move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn, unsigned long nr_pages, struct vmem_altmap *altmap) { @@ -804,43 +758,21 @@ struct zone * zone_for_pfn_range(int online_type, int nid, unsigned start_pfn, return default_zone_for_pfn(nid, start_pfn, nr_pages); } -/* - * Associates the given pfn range with the given node and the zone appropriate - * for the given online type. - */ -static struct zone * __meminit move_pfn_range(int online_type, int nid, - unsigned long start_pfn, unsigned long nr_pages) -{ - struct zone *zone; - - zone = zone_for_pfn_range(online_type, nid, start_pfn, nr_pages); - move_pfn_range_to_zone(zone, start_pfn, nr_pages, NULL); - return zone; -} - -int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_type) +int __ref online_pages(unsigned long pfn, unsigned long nr_pages, + int online_type, int nid) { unsigned long flags; unsigned long onlined_pages = 0; struct zone *zone; int need_zonelists_rebuild = 0; - int nid; int ret; struct memory_notify arg; - struct memory_block *mem; mem_hotplug_begin(); - /* - * We can't use pfn_to_nid() because nid might be stored in struct page - * which is not yet initialized. Instead, we find nid from memory block. - */ - mem = find_memory_block(__pfn_to_section(pfn)); - nid = mem->nid; - put_device(&mem->dev); - /* associate pfn range with the zone */ - zone = move_pfn_range(online_type, nid, pfn, nr_pages); + zone = zone_for_pfn_range(online_type, nid, pfn, nr_pages); + move_pfn_range_to_zone(zone, pfn, nr_pages, NULL); arg.start_pfn = pfn; arg.nr_pages = nr_pages; @@ -864,6 +796,7 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ 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; @@ -877,27 +810,22 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ shuffle_zone(zone); - if (onlined_pages) { - node_states_set_node(nid, &arg); - if (need_zonelists_rebuild) - build_all_zonelists(NULL); - else - zone_pcp_update(zone); - } + node_states_set_node(nid, &arg); + if (need_zonelists_rebuild) + build_all_zonelists(NULL); + else + zone_pcp_update(zone); init_per_zone_wmark_min(); - if (onlined_pages) { - kswapd_run(nid); - kcompactd_run(nid); - } + kswapd_run(nid); + kcompactd_run(nid); vm_total_pages = nr_free_pagecache_pages(); writeback_set_ratelimit(); - if (onlined_pages) - memory_notify(MEM_ONLINE, &arg); + memory_notify(MEM_ONLINE, &arg); mem_hotplug_done(); return 0; @@ -906,6 +834,7 @@ failed_addition: (unsigned long long) pfn << PAGE_SHIFT, (((unsigned long long) pfn + nr_pages) << PAGE_SHIFT) - 1); memory_notify(MEM_CANCEL_ONLINE, &arg); + remove_pfn_range_from_zone(zone, pfn, nr_pages); mem_hotplug_done(); return ret; } @@ -933,8 +862,11 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start) 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 @@ -943,6 +875,12 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start) 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 */ @@ -952,7 +890,6 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start) /* init node's zones as empty zones, we don't have any present pages.*/ free_area_init_core_hotplug(nid); - pgdat->per_cpu_nodestats = alloc_percpu(struct per_cpu_nodestat); /* * The node we allocated has no zone fallback lists. For avoiding @@ -1211,7 +1148,8 @@ static bool is_pageblock_removable_nolock(unsigned long pfn) if (!zone_spans_pfn(zone, pfn)) return false; - return !has_unmovable_pages(zone, page, 0, MIGRATE_MOVABLE, SKIP_HWPOISON); + return !has_unmovable_pages(zone, page, MIGRATE_MOVABLE, + MEMORY_OFFLINE); } /* Checks if this range of memory is likely to be hot-removable. */ @@ -1234,14 +1172,13 @@ bool is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages) } /* - * Confirm all pages in a range [start, end) belong to the same zone. - * When true, return its valid [start, end). + * Confirm all pages in a range [start, end) belong to the same zone (skipping + * memory holes). When true, return the zone. */ -int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn, - unsigned long *valid_start, unsigned long *valid_end) +struct zone *test_pages_in_a_zone(unsigned long start_pfn, + unsigned long end_pfn) { unsigned long pfn, sec_end_pfn; - unsigned long start, end; struct zone *zone = NULL; struct page *page; int i; @@ -1262,24 +1199,15 @@ int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn, continue; /* Check if we got outside of the zone */ if (zone && !zone_spans_pfn(zone, pfn + i)) - return 0; + return NULL; page = pfn_to_page(pfn + i); if (zone && page_zone(page) != zone) - return 0; - if (!zone) - start = pfn + i; + return NULL; zone = page_zone(page); - end = pfn + MAX_ORDER_NR_PAGES; } } - if (zone) { - *valid_start = start; - *valid_end = min(end, end_pfn); - return 1; - } else { - return 0; - } + return zone; } /* @@ -1309,7 +1237,7 @@ static unsigned long scan_movable_pages(unsigned long start, unsigned long end) head = compound_head(page); if (page_huge_active(head)) return pfn; - skip = (1 << compound_order(head)) - (page - head); + skip = compound_nr(head) - (page - head); pfn += skip - 1; } return 0; @@ -1347,7 +1275,7 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) if (PageHuge(page)) { struct page *head = compound_head(page); - pfn = page_to_pfn(head) + (1<<compound_order(head)) - 1; + pfn = page_to_pfn(head) + compound_nr(head) - 1; isolate_huge_page(head, &source); continue; } else if (PageTransHuge(page)) @@ -1408,9 +1336,7 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) return ret; } -/* - * remove from free_area[] and mark all as Reserved. - */ +/* 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) @@ -1428,7 +1354,8 @@ 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, true); + return test_pages_isolated(start_pfn, start_pfn + nr_pages, + MEMORY_OFFLINE); } static int __init cmdline_parse_movable_node(char *p) @@ -1509,37 +1436,58 @@ static void node_states_clear_node(int node, struct memory_notify *arg) node_clear_state(node, N_MEMORY); } +static int count_system_ram_pages_cb(unsigned long start_pfn, + unsigned long nr_pages, void *data) +{ + unsigned long *nr_system_ram_pages = data; + + *nr_system_ram_pages += nr_pages; + return 0; +} + static int __ref __offline_pages(unsigned long start_pfn, unsigned long end_pfn) { - unsigned long pfn, nr_pages; + unsigned long pfn, nr_pages = 0; unsigned long offlined_pages = 0; int ret, node, nr_isolate_pageblock; unsigned long flags; - unsigned long valid_start, valid_end; struct zone *zone; struct memory_notify arg; char *reason; mem_hotplug_begin(); + /* + * Don't allow to offline memory blocks that contain holes. + * Consequently, memory blocks with holes can never get onlined + * via the hotplug path - online_pages() - as hotplugged memory has + * no holes. This way, we e.g., don't have to worry about marking + * 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, + count_system_ram_pages_cb); + if (nr_pages != end_pfn - start_pfn) { + ret = -EINVAL; + reason = "memory holes"; + goto failed_removal; + } + /* This makes hotplug much easier...and readable. we assume this for now. .*/ - if (!test_pages_in_a_zone(start_pfn, end_pfn, &valid_start, - &valid_end)) { + zone = test_pages_in_a_zone(start_pfn, end_pfn); + if (!zone) { ret = -EINVAL; reason = "multizone range"; goto failed_removal; } - - zone = page_zone(pfn_to_page(valid_start)); 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, MIGRATE_MOVABLE, - SKIP_HWPOISON | REPORT_FAILURE); + MEMORY_OFFLINE | REPORT_FAILURE); if (ret < 0) { reason = "failure to isolate range"; goto failed_removal; @@ -1633,6 +1581,7 @@ static int __ref __offline_pages(unsigned long start_pfn, writeback_set_ratelimit(); memory_notify(MEM_OFFLINE, &arg); + remove_pfn_range_from_zone(zone, start_pfn, nr_pages); mem_hotplug_done(); return 0; @@ -1662,7 +1611,7 @@ static int check_memblock_offlined_cb(struct memory_block *mem, void *arg) 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; + endpa = beginpa + memory_block_size_bytes() - 1; pr_warn("removing memory fails, because memory [%pa-%pa] is onlined\n", &beginpa, &endpa); @@ -1687,6 +1636,18 @@ static int check_cpu_on_node(pg_data_t *pgdat) return 0; } +static int check_no_memblock_for_node_cb(struct memory_block *mem, void *arg) +{ + int nid = *(int *)arg; + + /* + * If a memory block belongs to multiple nodes, the stored nid is not + * reliable. However, such blocks are always online (e.g., cannot get + * offlined) and, therefore, are still spanned by the node. + */ + return mem->nid == nid ? -EEXIST : 0; +} + /** * try_offline_node * @nid: the node ID @@ -1699,25 +1660,24 @@ static int check_cpu_on_node(pg_data_t *pgdat) void try_offline_node(int nid) { pg_data_t *pgdat = NODE_DATA(nid); - unsigned long start_pfn = pgdat->node_start_pfn; - unsigned long end_pfn = start_pfn + pgdat->node_spanned_pages; - unsigned long pfn; - - for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { - unsigned long section_nr = pfn_to_section_nr(pfn); - - if (!present_section_nr(section_nr)) - continue; + int rc; - if (pfn_to_nid(pfn) != nid) - continue; + /* + * If the node still spans pages (especially ZONE_DEVICE), don't + * 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) + return; - /* - * some memory sections of this node are not removed, and we - * can't offline node now. - */ + /* + * Especially offline memory blocks might not be spanned by the + * node. They will get spanned by the node once they get onlined. + * However, they link to the node in sysfs and can get onlined later. + */ + rc = for_each_memory_block(&nid, check_no_memblock_for_node_cb); + if (rc) return; - } if (check_cpu_on_node(pgdat)) return; @@ -1757,8 +1717,6 @@ static int __ref try_remove_memory(int nid, u64 start, u64 size) BUG_ON(check_hotplug_memory_range(start, size)); - mem_hotplug_begin(); - /* * All memory blocks must be offlined before removing memory. Check * whether all memory blocks in question are offline and return error @@ -1770,13 +1728,18 @@ static int __ref try_remove_memory(int nid, u64 start, u64 size) /* remove memmap entry */ firmware_map_remove(start, start + size, "System RAM"); - memblock_free(start, size); - memblock_remove(start, size); - /* remove memory block devices before removing memory */ + /* + * Memory block device removal under the device_hotplug_lock is + * a barrier against racing online attempts. + */ remove_memory_block_devices(start, size); + mem_hotplug_begin(); + arch_remove_memory(nid, start, size, NULL); + memblock_free(start, size); + memblock_remove(start, size); __release_memory_resource(start, size); try_offline_node(nid); @@ -1800,7 +1763,7 @@ void __remove_memory(int nid, u64 start, u64 size) { /* - * trigger BUG() is some memory is not offlined prior to calling this + * trigger BUG() if some memory is not offlined prior to calling this * function */ if (try_remove_memory(nid, start, size)) |
