1 files changed, 387 insertions, 55 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 5e6fa06..506eac8 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -18,6 +18,7 @@
 #include <linux/mm.h>
 #include <linux/swap.h>
 #include <linux/interrupt.h>
+#include <linux/rwsem.h>
 #include <linux/pagemap.h>
 #include <linux/jiffies.h>
 #include <linux/bootmem.h>
@@ -61,6 +62,7 @@
 #include <linux/hugetlb.h>
 #include <linux/sched/rt.h>
 #include <linux/page_owner.h>
+#include <linux/kthread.h>
 
 #include <asm/sections.h>
 #include <asm/tlbflush.h>
@@ -235,6 +237,77 @@ EXPORT_SYMBOL(nr_online_nodes);
 
 int page_group_by_mobility_disabled __read_mostly;
 
+#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
+static inline void reset_deferred_meminit(pg_data_t *pgdat)
+{
+	pgdat->first_deferred_pfn = ULONG_MAX;
+}
+
+/* Returns true if the struct page for the pfn is uninitialised */
+static inline bool __meminit early_page_uninitialised(unsigned long pfn)
+{
+	int nid = early_pfn_to_nid(pfn);
+
+	if (pfn >= NODE_DATA(nid)->first_deferred_pfn)
+		return true;
+
+	return false;
+}
+
+static inline bool early_page_nid_uninitialised(unsigned long pfn, int nid)
+{
+	if (pfn >= NODE_DATA(nid)->first_deferred_pfn)
+		return true;
+
+	return false;
+}
+
+/*
+ * Returns false when the remaining initialisation should be deferred until
+ * later in the boot cycle when it can be parallelised.
+ */
+static inline bool update_defer_init(pg_data_t *pgdat,
+				unsigned long pfn, unsigned long zone_end,
+				unsigned long *nr_initialised)
+{
+	/* Always populate low zones for address-contrained allocations */
+	if (zone_end < pgdat_end_pfn(pgdat))
+		return true;
+
+	/* Initialise at least 2G of the highest zone */
+	(*nr_initialised)++;
+	if (*nr_initialised > (2UL << (30 - PAGE_SHIFT)) &&
+	    (pfn & (PAGES_PER_SECTION - 1)) == 0) {
+		pgdat->first_deferred_pfn = pfn;
+		return false;
+	}
+
+	return true;
+}
+#else
+static inline void reset_deferred_meminit(pg_data_t *pgdat)
+{
+}
+
+static inline bool early_page_uninitialised(unsigned long pfn)
+{
+	return false;
+}
+
+static inline bool early_page_nid_uninitialised(unsigned long pfn, int nid)
+{
+	return false;
+}
+
+static inline bool update_defer_init(pg_data_t *pgdat,
+				unsigned long pfn, unsigned long zone_end,
+				unsigned long *nr_initialised)
+{
+	return true;
+}
+#endif
+
+
 void set_pageblock_migratetype(struct page *page, int migratetype)
 {
 	if (unlikely(page_group_by_mobility_disabled &&
@@ -764,6 +837,75 @@ static int free_tail_pages_check(struct page *head_page, struct page *page)
 	return 0;
 }
 
+static void __meminit __init_single_page(struct page *page, unsigned long pfn,
+				unsigned long zone, int nid)
+{
+	set_page_links(page, zone, nid, pfn);
+	init_page_count(page);
+	page_mapcount_reset(page);
+	page_cpupid_reset_last(page);
+
+	INIT_LIST_HEAD(&page->lru);
+#ifdef WANT_PAGE_VIRTUAL
+	/* The shift won't overflow because ZONE_NORMAL is below 4G. */
+	if (!is_highmem_idx(zone))
+		set_page_address(page, __va(pfn << PAGE_SHIFT));
+#endif
+}
+
+static void __meminit __init_single_pfn(unsigned long pfn, unsigned long zone,
+					int nid)
+{
+	return __init_single_page(pfn_to_page(pfn), pfn, zone, nid);
+}
+
+#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
+static void init_reserved_page(unsigned long pfn)
+{
+	pg_data_t *pgdat;
+	int nid, zid;
+
+	if (!early_page_uninitialised(pfn))
+		return;
+
+	nid = early_pfn_to_nid(pfn);
+	pgdat = NODE_DATA(nid);
+
+	for (zid = 0; zid < MAX_NR_ZONES; zid++) {
+		struct zone *zone = &pgdat->node_zones[zid];
+
+		if (pfn >= zone->zone_start_pfn && pfn < zone_end_pfn(zone))
+			break;
+	}
+	__init_single_pfn(pfn, zid, nid);
+}
+#else
+static inline void init_reserved_page(unsigned long pfn)
+{
+}
+#endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
+
+/*
+ * Initialised pages do not have PageReserved set. This function is
+ * called for each range allocated by the bootmem allocator and
+ * marks the pages PageReserved. The remaining valid pages are later
+ * sent to the buddy page allocator.
+ */
+void __meminit reserve_bootmem_region(unsigned long start, unsigned long end)
+{
+	unsigned long start_pfn = PFN_DOWN(start);
+	unsigned long end_pfn = PFN_UP(end);
+
+	for (; start_pfn < end_pfn; start_pfn++) {
+		if (pfn_valid(start_pfn)) {
+			struct page *page = pfn_to_page(start_pfn);
+
+			init_reserved_page(start_pfn);
+			SetPageReserved(page);
+		}
+	}
+}
+
 static bool free_pages_prepare(struct page *page, unsigned int order)
 {
 	bool compound = PageCompound(page);
@@ -818,7 +960,8 @@ static void __free_pages_ok(struct page *page, unsigned int order)
 	local_irq_restore(flags);
 }
 
-void __init __free_pages_bootmem(struct page *page, unsigned int order)
+static void __init __free_pages_boot_core(struct page *page,
+					unsigned long pfn, unsigned int order)
 {
 	unsigned int nr_pages = 1 << order;
 	struct page *p = page;
@@ -838,6 +981,223 @@ void __init __free_pages_bootmem(struct page *page, unsigned int order)
 	__free_pages(page, order);
 }
 
+#if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
+	defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
+/* Only safe to use early in boot when initialisation is single-threaded */
+static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata;
+
+int __meminit early_pfn_to_nid(unsigned long pfn)
+{
+	int nid;
+
+	/* The system will behave unpredictably otherwise */
+	BUG_ON(system_state != SYSTEM_BOOTING);
+
+	nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache);
+	if (nid >= 0)
+		return nid;
+	/* just returns 0 */
+	return 0;
+}
+#endif
+
+#ifdef CONFIG_NODES_SPAN_OTHER_NODES
+static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
+					struct mminit_pfnnid_cache *state)
+{
+	int nid;
+
+	nid = __early_pfn_to_nid(pfn, state);
+	if (nid >= 0 && nid != node)
+		return false;
+	return true;
+}
+
+/* Only safe to use early in boot when initialisation is single-threaded */
+static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
+{
+	return meminit_pfn_in_nid(pfn, node, &early_pfnnid_cache);
+}
+
+#else
+
+static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
+{
+	return true;
+}
+static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
+					struct mminit_pfnnid_cache *state)
+{
+	return true;
+}
+#endif
+
+
+void __init __free_pages_bootmem(struct page *page, unsigned long pfn,
+							unsigned int order)
+{
+	if (early_page_uninitialised(pfn))
+		return;
+	return __free_pages_boot_core(page, pfn, order);
+}
+
+#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
+static void __init deferred_free_range(struct page *page,
+					unsigned long pfn, int nr_pages)
+{
+	int i;
+
+	if (!page)
+		return;
+
+	/* Free a large naturally-aligned chunk if possible */
+	if (nr_pages == MAX_ORDER_NR_PAGES &&
+	    (pfn & (MAX_ORDER_NR_PAGES-1)) == 0) {
+		set_pageblock_migratetype(page, MIGRATE_MOVABLE);
+		__free_pages_boot_core(page, pfn, MAX_ORDER-1);
+		return;
+	}
+
+	for (i = 0; i < nr_pages; i++, page++, pfn++)
+		__free_pages_boot_core(page, pfn, 0);
+}
+
+static __initdata DECLARE_RWSEM(pgdat_init_rwsem);
+
+/* Initialise remaining memory on a node */
+static int __init deferred_init_memmap(void *data)
+{
+	pg_data_t *pgdat = data;
+	int nid = pgdat->node_id;
+	struct mminit_pfnnid_cache nid_init_state = { };
+	unsigned long start = jiffies;
+	unsigned long nr_pages = 0;
+	unsigned long walk_start, walk_end;
+	int i, zid;
+	struct zone *zone;
+	unsigned long first_init_pfn = pgdat->first_deferred_pfn;
+	const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
+
+	if (first_init_pfn == ULONG_MAX) {
+		up_read(&pgdat_init_rwsem);
+		return 0;
+	}
+
+	/* Bind memory initialisation thread to a local node if possible */
+	if (!cpumask_empty(cpumask))
+		set_cpus_allowed_ptr(current, cpumask);
+
+	/* Sanity check boundaries */
+	BUG_ON(pgdat->first_deferred_pfn < pgdat->node_start_pfn);
+	BUG_ON(pgdat->first_deferred_pfn > pgdat_end_pfn(pgdat));
+	pgdat->first_deferred_pfn = ULONG_MAX;
+
+	/* Only the highest zone is deferred so find it */
+	for (zid = 0; zid < MAX_NR_ZONES; zid++) {
+		zone = pgdat->node_zones + zid;
+		if (first_init_pfn < zone_end_pfn(zone))
+			break;
+	}
+
+	for_each_mem_pfn_range(i, nid, &walk_start, &walk_end, NULL) {
+		unsigned long pfn, end_pfn;
+		struct page *page = NULL;
+		struct page *free_base_page = NULL;
+		unsigned long free_base_pfn = 0;
+		int nr_to_free = 0;
+
+		end_pfn = min(walk_end, zone_end_pfn(zone));
+		pfn = first_init_pfn;
+		if (pfn < walk_start)
+			pfn = walk_start;
+		if (pfn < zone->zone_start_pfn)
+			pfn = zone->zone_start_pfn;
+
+		for (; pfn < end_pfn; pfn++) {
+			if (!pfn_valid_within(pfn))
+				goto free_range;
+
+			/*
+			 * Ensure pfn_valid is checked every
+			 * MAX_ORDER_NR_PAGES for memory holes
+			 */
+			if ((pfn & (MAX_ORDER_NR_PAGES - 1)) == 0) {
+				if (!pfn_valid(pfn)) {
+					page = NULL;
+					goto free_range;
+				}
+			}
+
+			if (!meminit_pfn_in_nid(pfn, nid, &nid_init_state)) {
+				page = NULL;
+				goto free_range;
+			}
+
+			/* Minimise pfn page lookups and scheduler checks */
+			if (page && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0) {
+				page++;
+			} else {
+				nr_pages += nr_to_free;
+				deferred_free_range(free_base_page,
+						free_base_pfn, nr_to_free);
+				free_base_page = NULL;
+				free_base_pfn = nr_to_free = 0;
+
+				page = pfn_to_page(pfn);
+				cond_resched();
+			}
+
+			if (page->flags) {
+				VM_BUG_ON(page_zone(page) != zone);
+				goto free_range;
+			}
+
+			__init_single_page(page, pfn, zid, nid);
+			if (!free_base_page) {
+				free_base_page = page;
+				free_base_pfn = pfn;
+				nr_to_free = 0;
+			}
+			nr_to_free++;
+
+			/* Where possible, batch up pages for a single free */
+			continue;
+free_range:
+			/* Free the current block of pages to allocator */
+			nr_pages += nr_to_free;
+			deferred_free_range(free_base_page, free_base_pfn,
+								nr_to_free);
+			free_base_page = NULL;
+			free_base_pfn = nr_to_free = 0;
+		}
+
+		first_init_pfn = max(end_pfn, first_init_pfn);
+	}
+
+	/* Sanity check that the next zone really is unpopulated */
+	WARN_ON(++zid < MAX_NR_ZONES && populated_zone(++zone));
+
+	pr_info("node %d initialised, %lu pages in %ums\n", nid, nr_pages,
+					jiffies_to_msecs(jiffies - start));
+	up_read(&pgdat_init_rwsem);
+	return 0;
+}
+
+void __init page_alloc_init_late(void)
+{
+	int nid;
+
+	for_each_node_state(nid, N_MEMORY) {
+		down_read(&pgdat_init_rwsem);
+		kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid);
+	}
+
+	/* Block until all are initialised */
+	down_write(&pgdat_init_rwsem);
+	up_write(&pgdat_init_rwsem);
+}
+#endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
+
 #ifdef CONFIG_CMA
 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
 void __init init_cma_reserved_pageblock(struct page *page)
@@ -4150,6 +4510,9 @@ static void setup_zone_migrate_reserve(struct zone *zone)
 	zone->nr_migrate_reserve_block = reserve;
 
 	for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
+		if (!early_page_nid_uninitialised(pfn, zone_to_nid(zone)))
+			return;
+
 		if (!pfn_valid(pfn))
 			continue;
 		page = pfn_to_page(pfn);
@@ -4212,15 +4575,16 @@ static void setup_zone_migrate_reserve(struct zone *zone)
 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
 		unsigned long start_pfn, enum memmap_context context)
 {
-	struct page *page;
+	pg_data_t *pgdat = NODE_DATA(nid);
 	unsigned long end_pfn = start_pfn + size;
 	unsigned long pfn;
 	struct zone *z;
+	unsigned long nr_initialised = 0;
 
 	if (highest_memmap_pfn < end_pfn - 1)
 		highest_memmap_pfn = end_pfn - 1;
 
-	z = &NODE_DATA(nid)->node_zones[zone];
+	z = &pgdat->node_zones[zone];
 	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
 		/*
 		 * There can be holes in boot-time mem_map[]s
@@ -4232,14 +4596,11 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
 				continue;
 			if (!early_pfn_in_nid(pfn, nid))
 				continue;
+			if (!update_defer_init(pgdat, pfn, end_pfn,
+						&nr_initialised))
+				break;
 		}
-		page = pfn_to_page(pfn);
-		set_page_links(page, zone, nid, pfn);
-		mminit_verify_page_links(page, zone, nid, pfn);
-		init_page_count(page);
-		page_mapcount_reset(page);
-		page_cpupid_reset_last(page);
-		SetPageReserved(page);
+
 		/*
 		 * Mark the block movable so that blocks are reserved for
 		 * movable at startup. This will force kernel allocations
@@ -4254,17 +4615,14 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
 		 * check here not to call set_pageblock_migratetype() against
 		 * pfn out of zone.
 		 */
-		if ((z->zone_start_pfn <= pfn)
-		    && (pfn < zone_end_pfn(z))
-		    && !(pfn & (pageblock_nr_pages - 1)))
-			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
+		if (!(pfn & (pageblock_nr_pages - 1))) {
+			struct page *page = pfn_to_page(pfn);
 
-		INIT_LIST_HEAD(&page->lru);
-#ifdef WANT_PAGE_VIRTUAL
-		/* The shift won't overflow because ZONE_NORMAL is below 4G. */
-		if (!is_highmem_idx(zone))
-			set_page_address(page, __va(pfn << PAGE_SHIFT));
-#endif
+			__init_single_page(page, pfn, zone, nid);
+			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
+		} else {
+			__init_single_pfn(pfn, zone, nid);
+		}
 	}
 }
 
@@ -4522,57 +4880,30 @@ int __meminit init_currently_empty_zone(struct zone *zone,
 
 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
+
 /*
  * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
  */
-int __meminit __early_pfn_to_nid(unsigned long pfn)
+int __meminit __early_pfn_to_nid(unsigned long pfn,
+					struct mminit_pfnnid_cache *state)
 {
 	unsigned long start_pfn, end_pfn;
 	int nid;
-	/*
-	 * NOTE: The following SMP-unsafe globals are only used early in boot
-	 * when the kernel is running single-threaded.
-	 */
-	static unsigned long __meminitdata last_start_pfn, last_end_pfn;
-	static int __meminitdata last_nid;
 
-	if (last_start_pfn <= pfn && pfn < last_end_pfn)
-		return last_nid;
+	if (state->last_start <= pfn && pfn < state->last_end)
+		return state->last_nid;
 
 	nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
 	if (nid != -1) {
-		last_start_pfn = start_pfn;
-		last_end_pfn = end_pfn;
-		last_nid = nid;
+		state->last_start = start_pfn;
+		state->last_end = end_pfn;
+		state->last_nid = nid;
 	}
 
 	return nid;
 }
 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
 
-int __meminit early_pfn_to_nid(unsigned long pfn)
-{
-	int nid;
-
-	nid = __early_pfn_to_nid(pfn);
-	if (nid >= 0)
-		return nid;
-	/* just returns 0 */
-	return 0;
-}
-
-#ifdef CONFIG_NODES_SPAN_OTHER_NODES
-bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
-{
-	int nid;
-
-	nid = __early_pfn_to_nid(pfn);
-	if (nid >= 0 && nid != node)
-		return false;
-	return true;
-}
-#endif
-
 /**
  * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
  * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
@@ -5090,6 +5421,7 @@ void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
 	/* pg_data_t should be reset to zero when it's allocated */
 	WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
 
+	reset_deferred_meminit(pgdat);
 	pgdat->node_id = nid;
 	pgdat->node_start_pfn = node_start_pfn;
 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP