1 files changed, 202 insertions, 92 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index c3edb62..327516b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -61,10 +61,14 @@
 #include <linux/hugetlb.h>
 #include <linux/sched/rt.h>
 
+#include <asm/sections.h>
 #include <asm/tlbflush.h>
 #include <asm/div64.h>
 #include "internal.h"
 
+/* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
+static DEFINE_MUTEX(pcp_batch_high_lock);
+
 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
 DEFINE_PER_CPU(int, numa_node);
 EXPORT_PER_CPU_SYMBOL(numa_node);
@@ -100,6 +104,9 @@ nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
 };
 EXPORT_SYMBOL(node_states);
 
+/* Protect totalram_pages and zone->managed_pages */
+static DEFINE_SPINLOCK(managed_page_count_lock);
+
 unsigned long totalram_pages __read_mostly;
 unsigned long totalreserve_pages __read_mostly;
 /*
@@ -739,14 +746,7 @@ static void __free_pages_ok(struct page *page, unsigned int order)
 	local_irq_restore(flags);
 }
 
-/*
- * Read access to zone->managed_pages is safe because it's unsigned long,
- * but we still need to serialize writers. Currently all callers of
- * __free_pages_bootmem() except put_page_bootmem() should only be used
- * at boot time. So for shorter boot time, we shift the burden to
- * put_page_bootmem() to serialize writers.
- */
-void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
+void __init __free_pages_bootmem(struct page *page, unsigned int order)
 {
 	unsigned int nr_pages = 1 << order;
 	unsigned int loop;
@@ -781,11 +781,7 @@ void __init init_cma_reserved_pageblock(struct page *page)
 	set_page_refcounted(page);
 	set_pageblock_migratetype(page, MIGRATE_CMA);
 	__free_pages(page, pageblock_order);
-	totalram_pages += pageblock_nr_pages;
-#ifdef CONFIG_HIGHMEM
-	if (PageHighMem(page))
-		totalhigh_pages += pageblock_nr_pages;
-#endif
+	adjust_managed_page_count(page, pageblock_nr_pages);
 }
 #endif
 
@@ -1179,10 +1175,12 @@ void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
 {
 	unsigned long flags;
 	int to_drain;
+	unsigned long batch;
 
 	local_irq_save(flags);
-	if (pcp->count >= pcp->batch)
-		to_drain = pcp->batch;
+	batch = ACCESS_ONCE(pcp->batch);
+	if (pcp->count >= batch)
+		to_drain = batch;
 	else
 		to_drain = pcp->count;
 	if (to_drain > 0) {
@@ -1350,8 +1348,9 @@ void free_hot_cold_page(struct page *page, int cold)
 		list_add(&page->lru, &pcp->lists[migratetype]);
 	pcp->count++;
 	if (pcp->count >= pcp->high) {
-		free_pcppages_bulk(zone, pcp->batch, pcp);
-		pcp->count -= pcp->batch;
+		unsigned long batch = ACCESS_ONCE(pcp->batch);
+		free_pcppages_bulk(zone, batch, pcp);
+		pcp->count -= batch;
 	}
 
 out:
@@ -2839,7 +2838,7 @@ EXPORT_SYMBOL(free_pages_exact);
  * nr_free_zone_pages() counts the number of counts pages which are beyond the
  * high watermark within all zones at or below a given zone index.  For each
  * zone, the number of pages is calculated as:
- *     present_pages - high_pages
+ *     managed_pages - high_pages
  */
 static unsigned long nr_free_zone_pages(int offset)
 {
@@ -2906,9 +2905,13 @@ EXPORT_SYMBOL(si_meminfo);
 #ifdef CONFIG_NUMA
 void si_meminfo_node(struct sysinfo *val, int nid)
 {
+	int zone_type;		/* needs to be signed */
+	unsigned long managed_pages = 0;
 	pg_data_t *pgdat = NODE_DATA(nid);
 
-	val->totalram = pgdat->node_present_pages;
+	for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
+		managed_pages += pgdat->node_zones[zone_type].managed_pages;
+	val->totalram = managed_pages;
 	val->freeram = node_page_state(nid, NR_FREE_PAGES);
 #ifdef CONFIG_HIGHMEM
 	val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].managed_pages;
@@ -3250,18 +3253,25 @@ int numa_zonelist_order_handler(ctl_table *table, int write,
 	static DEFINE_MUTEX(zl_order_mutex);
 
 	mutex_lock(&zl_order_mutex);
-	if (write)
-		strcpy(saved_string, (char*)table->data);
+	if (write) {
+		if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) {
+			ret = -EINVAL;
+			goto out;
+		}
+		strcpy(saved_string, (char *)table->data);
+	}
 	ret = proc_dostring(table, write, buffer, length, ppos);
 	if (ret)
 		goto out;
 	if (write) {
 		int oldval = user_zonelist_order;
-		if (__parse_numa_zonelist_order((char*)table->data)) {
+
+		ret = __parse_numa_zonelist_order((char *)table->data);
+		if (ret) {
 			/*
 			 * bogus value.  restore saved string
 			 */
-			strncpy((char*)table->data, saved_string,
+			strncpy((char *)table->data, saved_string,
 				NUMA_ZONELIST_ORDER_LEN);
 			user_zonelist_order = oldval;
 		} else if (oldval != user_zonelist_order) {
@@ -3425,8 +3435,8 @@ static int default_zonelist_order(void)
 			z = &NODE_DATA(nid)->node_zones[zone_type];
 			if (populated_zone(z)) {
 				if (zone_type < ZONE_NORMAL)
-					low_kmem_size += z->present_pages;
-				total_size += z->present_pages;
+					low_kmem_size += z->managed_pages;
+				total_size += z->managed_pages;
 			} else if (zone_type == ZONE_NORMAL) {
 				/*
 				 * If any node has only lowmem, then node order
@@ -3705,12 +3715,12 @@ void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
 		mminit_verify_zonelist();
 		cpuset_init_current_mems_allowed();
 	} else {
-		/* we have to stop all cpus to guarantee there is no user
-		   of zonelist */
 #ifdef CONFIG_MEMORY_HOTPLUG
 		if (zone)
 			setup_zone_pageset(zone);
 #endif
+		/* we have to stop all cpus to guarantee there is no user
+		   of zonelist */
 		stop_machine(__build_all_zonelists, pgdat, NULL);
 		/* cpuset refresh routine should be here */
 	}
@@ -4032,7 +4042,40 @@ static int __meminit zone_batchsize(struct zone *zone)
 #endif
 }
 
-static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
+/*
+ * pcp->high and pcp->batch values are related and dependent on one another:
+ * ->batch must never be higher then ->high.
+ * The following function updates them in a safe manner without read side
+ * locking.
+ *
+ * Any new users of pcp->batch and pcp->high should ensure they can cope with
+ * those fields changing asynchronously (acording the the above rule).
+ *
+ * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
+ * outside of boot time (or some other assurance that no concurrent updaters
+ * exist).
+ */
+static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
+		unsigned long batch)
+{
+       /* start with a fail safe value for batch */
+	pcp->batch = 1;
+	smp_wmb();
+
+       /* Update high, then batch, in order */
+	pcp->high = high;
+	smp_wmb();
+
+	pcp->batch = batch;
+}
+
+/* a companion to pageset_set_high() */
+static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch)
+{
+	pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch));
+}
+
+static void pageset_init(struct per_cpu_pageset *p)
 {
 	struct per_cpu_pages *pcp;
 	int migratetype;
@@ -4041,45 +4084,55 @@ static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
 
 	pcp = &p->pcp;
 	pcp->count = 0;
-	pcp->high = 6 * batch;
-	pcp->batch = max(1UL, 1 * batch);
 	for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
 		INIT_LIST_HEAD(&pcp->lists[migratetype]);
 }
 
+static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
+{
+	pageset_init(p);
+	pageset_set_batch(p, batch);
+}
+
 /*
- * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
+ * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
  * to the value high for the pageset p.
  */
-
-static void setup_pagelist_highmark(struct per_cpu_pageset *p,
+static void pageset_set_high(struct per_cpu_pageset *p,
 				unsigned long high)
 {
-	struct per_cpu_pages *pcp;
+	unsigned long batch = max(1UL, high / 4);
+	if ((high / 4) > (PAGE_SHIFT * 8))
+		batch = PAGE_SHIFT * 8;
 
-	pcp = &p->pcp;
-	pcp->high = high;
-	pcp->batch = max(1UL, high/4);
-	if ((high/4) > (PAGE_SHIFT * 8))
-		pcp->batch = PAGE_SHIFT * 8;
+	pageset_update(&p->pcp, high, batch);
 }
 
-static void __meminit setup_zone_pageset(struct zone *zone)
+static void __meminit pageset_set_high_and_batch(struct zone *zone,
+		struct per_cpu_pageset *pcp)
 {
-	int cpu;
-
-	zone->pageset = alloc_percpu(struct per_cpu_pageset);
+	if (percpu_pagelist_fraction)
+		pageset_set_high(pcp,
+			(zone->managed_pages /
+				percpu_pagelist_fraction));
+	else
+		pageset_set_batch(pcp, zone_batchsize(zone));
+}
 
-	for_each_possible_cpu(cpu) {
-		struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
+static void __meminit zone_pageset_init(struct zone *zone, int cpu)
+{
+	struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
 
-		setup_pageset(pcp, zone_batchsize(zone));
+	pageset_init(pcp);
+	pageset_set_high_and_batch(zone, pcp);
+}
 
-		if (percpu_pagelist_fraction)
-			setup_pagelist_highmark(pcp,
-				(zone->managed_pages /
-					percpu_pagelist_fraction));
-	}
+static void __meminit setup_zone_pageset(struct zone *zone)
+{
+	int cpu;
+	zone->pageset = alloc_percpu(struct per_cpu_pageset);
+	for_each_possible_cpu(cpu)
+		zone_pageset_init(zone, cpu);
 }
 
 /*
@@ -5150,35 +5203,101 @@ early_param("movablecore", cmdline_parse_movablecore);
 
 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
 
-unsigned long free_reserved_area(unsigned long start, unsigned long end,
-				 int poison, char *s)
+void adjust_managed_page_count(struct page *page, long count)
+{
+	spin_lock(&managed_page_count_lock);
+	page_zone(page)->managed_pages += count;
+	totalram_pages += count;
+#ifdef CONFIG_HIGHMEM
+	if (PageHighMem(page))
+		totalhigh_pages += count;
+#endif
+	spin_unlock(&managed_page_count_lock);
+}
+EXPORT_SYMBOL(adjust_managed_page_count);
+
+unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
 {
-	unsigned long pages, pos;
+	void *pos;
+	unsigned long pages = 0;
 
-	pos = start = PAGE_ALIGN(start);
-	end &= PAGE_MASK;
-	for (pages = 0; pos < end; pos += PAGE_SIZE, pages++) {
-		if (poison)
-			memset((void *)pos, poison, PAGE_SIZE);
-		free_reserved_page(virt_to_page((void *)pos));
+	start = (void *)PAGE_ALIGN((unsigned long)start);
+	end = (void *)((unsigned long)end & PAGE_MASK);
+	for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
+		if ((unsigned int)poison <= 0xFF)
+			memset(pos, poison, PAGE_SIZE);
+		free_reserved_page(virt_to_page(pos));
 	}
 
 	if (pages && s)
-		pr_info("Freeing %s memory: %ldK (%lx - %lx)\n",
+		pr_info("Freeing %s memory: %ldK (%p - %p)\n",
 			s, pages << (PAGE_SHIFT - 10), start, end);
 
 	return pages;
 }
+EXPORT_SYMBOL(free_reserved_area);
 
 #ifdef	CONFIG_HIGHMEM
 void free_highmem_page(struct page *page)
 {
 	__free_reserved_page(page);
 	totalram_pages++;
+	page_zone(page)->managed_pages++;
 	totalhigh_pages++;
 }
 #endif
 
+
+void __init mem_init_print_info(const char *str)
+{
+	unsigned long physpages, codesize, datasize, rosize, bss_size;
+	unsigned long init_code_size, init_data_size;
+
+	physpages = get_num_physpages();
+	codesize = _etext - _stext;
+	datasize = _edata - _sdata;
+	rosize = __end_rodata - __start_rodata;
+	bss_size = __bss_stop - __bss_start;
+	init_data_size = __init_end - __init_begin;
+	init_code_size = _einittext - _sinittext;
+
+	/*
+	 * Detect special cases and adjust section sizes accordingly:
+	 * 1) .init.* may be embedded into .data sections
+	 * 2) .init.text.* may be out of [__init_begin, __init_end],
+	 *    please refer to arch/tile/kernel/vmlinux.lds.S.
+	 * 3) .rodata.* may be embedded into .text or .data sections.
+	 */
+#define adj_init_size(start, end, size, pos, adj) \
+	if (start <= pos && pos < end && size > adj) \
+		size -= adj;
+
+	adj_init_size(__init_begin, __init_end, init_data_size,
+		     _sinittext, init_code_size);
+	adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
+	adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
+	adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
+	adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
+
+#undef	adj_init_size
+
+	printk("Memory: %luK/%luK available "
+	       "(%luK kernel code, %luK rwdata, %luK rodata, "
+	       "%luK init, %luK bss, %luK reserved"
+#ifdef	CONFIG_HIGHMEM
+	       ", %luK highmem"
+#endif
+	       "%s%s)\n",
+	       nr_free_pages() << (PAGE_SHIFT-10), physpages << (PAGE_SHIFT-10),
+	       codesize >> 10, datasize >> 10, rosize >> 10,
+	       (init_data_size + init_code_size) >> 10, bss_size >> 10,
+	       (physpages - totalram_pages) << (PAGE_SHIFT-10),
+#ifdef	CONFIG_HIGHMEM
+	       totalhigh_pages << (PAGE_SHIFT-10),
+#endif
+	       str ? ", " : "", str ? str : "");
+}
+
 /**
  * set_dma_reserve - set the specified number of pages reserved in the first zone
  * @new_dma_reserve: The number of pages to mark reserved
@@ -5540,7 +5659,6 @@ int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
  * cpu.  It is the fraction of total pages in each zone that a hot per cpu pagelist
  * can have before it gets flushed back to buddy allocator.
  */
-
 int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
 	void __user *buffer, size_t *length, loff_t *ppos)
 {
@@ -5551,14 +5669,16 @@ int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
 	ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
 	if (!write || (ret < 0))
 		return ret;
+
+	mutex_lock(&pcp_batch_high_lock);
 	for_each_populated_zone(zone) {
-		for_each_possible_cpu(cpu) {
-			unsigned long  high;
-			high = zone->managed_pages / percpu_pagelist_fraction;
-			setup_pagelist_highmark(
-				per_cpu_ptr(zone->pageset, cpu), high);
-		}
+		unsigned long  high;
+		high = zone->managed_pages / percpu_pagelist_fraction;
+		for_each_possible_cpu(cpu)
+			pageset_set_high(per_cpu_ptr(zone->pageset, cpu),
+					 high);
 	}
+	mutex_unlock(&pcp_batch_high_lock);
 	return 0;
 }
 
@@ -6047,32 +6167,18 @@ void free_contig_range(unsigned long pfn, unsigned nr_pages)
 #endif
 
 #ifdef CONFIG_MEMORY_HOTPLUG
-static int __meminit __zone_pcp_update(void *data)
-{
-	struct zone *zone = data;
-	int cpu;
-	unsigned long batch = zone_batchsize(zone), flags;
-
-	for_each_possible_cpu(cpu) {
-		struct per_cpu_pageset *pset;
-		struct per_cpu_pages *pcp;
-
-		pset = per_cpu_ptr(zone->pageset, cpu);
-		pcp = &pset->pcp;
-
-		local_irq_save(flags);
-		if (pcp->count > 0)
-			free_pcppages_bulk(zone, pcp->count, pcp);
-		drain_zonestat(zone, pset);
-		setup_pageset(pset, batch);
-		local_irq_restore(flags);
-	}
-	return 0;
-}
-
+/*
+ * The zone indicated has a new number of managed_pages; batch sizes and percpu
+ * page high values need to be recalulated.
+ */
 void __meminit zone_pcp_update(struct zone *zone)
 {
-	stop_machine(__zone_pcp_update, zone, NULL);
+	unsigned cpu;
+	mutex_lock(&pcp_batch_high_lock);
+	for_each_possible_cpu(cpu)
+		pageset_set_high_and_batch(zone,
+				per_cpu_ptr(zone->pageset, cpu));
+	mutex_unlock(&pcp_batch_high_lock);
 }
 #endif
 
@@ -6142,6 +6248,10 @@ __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
 		list_del(&page->lru);
 		rmv_page_order(page);
 		zone->free_area[order].nr_free--;
+#ifdef CONFIG_HIGHMEM
+		if (PageHighMem(page))
+			totalhigh_pages -= 1 << order;
+#endif
 		for (i = 0; i < (1 << order); i++)
 			SetPageReserved((page+i));
 		pfn += (1 << order);