X-Git-Url: https://nv-tegra.nvidia.com/r/gitweb?p=linux-2.6.git;a=blobdiff_plain;f=mm%2Fmemory_hotplug.c;h=c46887b5a11eaa5bbe48008d16ad71bd37f7302f;hp=85eb4d342ac5010ccc0997be9a251d20cb82bb50;hb=6a7ebdf2fd15417e87b4fd02ff411aeaca34da5f;hpb=cf23422b9d76215316855253da491d4c9f294372

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 85eb4d342ac..c46887b5a11 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -34,6 +34,23 @@
 
 #include "internal.h"
 
+DEFINE_MUTEX(mem_hotplug_mutex);
+
+void lock_memory_hotplug(void)
+{
+	mutex_lock(&mem_hotplug_mutex);
+
+	/* for exclusive hibernation if CONFIG_HIBERNATION=y */
+	lock_system_sleep();
+}
+
+void unlock_memory_hotplug(void)
+{
+	unlock_system_sleep();
+	mutex_unlock(&mem_hotplug_mutex);
+}
+
+
 /* add this memory to iomem resource */
 static struct resource *register_memory_resource(u64 start, u64 size)
 {
@@ -65,9 +82,10 @@ static void release_memory_resource(struct resource *res)
 
 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
 #ifndef CONFIG_SPARSEMEM_VMEMMAP
-static void get_page_bootmem(unsigned long info,  struct page *page, int type)
+static void get_page_bootmem(unsigned long info,  struct page *page,
+			     unsigned long type)
 {
-	atomic_set(&page->_mapcount, type);
+	page->lru.next = (struct list_head *) type;
 	SetPagePrivate(page);
 	set_page_private(page, info);
 	atomic_inc(&page->_count);
@@ -77,15 +95,16 @@ static void get_page_bootmem(unsigned long info,  struct page *page, int type)
  * so use __ref to tell modpost not to generate a warning */
 void __ref put_page_bootmem(struct page *page)
 {
-	int type;
+	unsigned long type;
 
-	type = atomic_read(&page->_mapcount);
-	BUG_ON(type >= -1);
+	type = (unsigned long) page->lru.next;
+	BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
+	       type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE);
 
 	if (atomic_dec_return(&page->_count) == 1) {
 		ClearPagePrivate(page);
 		set_page_private(page, 0);
-		reset_page_mapcount(page);
+		INIT_LIST_HEAD(&page->lru);
 		__free_pages_bootmem(page, 0);
 	}
 
@@ -355,10 +374,6 @@ void online_page(struct page *page)
 		totalhigh_pages++;
 #endif
 
-#ifdef CONFIG_FLATMEM
-	max_mapnr = max(page_to_pfn(page), max_mapnr);
-#endif
-
 	ClearPageReserved(page);
 	init_page_count(page);
 	__free_page(page);
@@ -381,7 +396,7 @@ static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
 }
 
 
-int online_pages(unsigned long pfn, unsigned long nr_pages)
+int __ref online_pages(unsigned long pfn, unsigned long nr_pages)
 {
 	unsigned long onlined_pages = 0;
 	struct zone *zone;
@@ -390,6 +405,7 @@ int online_pages(unsigned long pfn, unsigned long nr_pages)
 	int ret;
 	struct memory_notify arg;
 
+	lock_memory_hotplug();
 	arg.start_pfn = pfn;
 	arg.nr_pages = nr_pages;
 	arg.status_change_nid = -1;
@@ -402,6 +418,7 @@ int online_pages(unsigned long pfn, unsigned long nr_pages)
 	ret = notifier_to_errno(ret);
 	if (ret) {
 		memory_notify(MEM_CANCEL_ONLINE, &arg);
+		unlock_memory_hotplug();
 		return ret;
 	}
 	/*
@@ -415,38 +432,44 @@ int online_pages(unsigned long pfn, unsigned long nr_pages)
 	 * This means the page allocator ignores this zone.
 	 * So, zonelist must be updated after online.
 	 */
+	mutex_lock(&zonelists_mutex);
 	if (!populated_zone(zone))
 		need_zonelists_rebuild = 1;
 
 	ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages,
 		online_pages_range);
 	if (ret) {
+		mutex_unlock(&zonelists_mutex);
 		printk(KERN_DEBUG "online_pages %lx at %lx failed\n",
 			nr_pages, pfn);
 		memory_notify(MEM_CANCEL_ONLINE, &arg);
+		unlock_memory_hotplug();
 		return ret;
 	}
 
 	zone->present_pages += onlined_pages;
 	zone->zone_pgdat->node_present_pages += onlined_pages;
+	if (need_zonelists_rebuild)
+		build_all_zonelists(zone);
+	else
+		zone_pcp_update(zone);
+
+	mutex_unlock(&zonelists_mutex);
+
+	init_per_zone_wmark_min();
 
-	zone_pcp_update(zone);
-	setup_per_zone_wmarks();
-	calculate_zone_inactive_ratio(zone);
 	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();
-	else
-		vm_total_pages = nr_free_pagecache_pages();
+	vm_total_pages = nr_free_pagecache_pages();
 
 	writeback_set_ratelimit();
 
 	if (onlined_pages)
 		memory_notify(MEM_ONLINE, &arg);
+	unlock_memory_hotplug();
 
 	return 0;
 }
@@ -471,6 +494,14 @@ 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_node(nid, zones_size, start_pfn, zholes_size);
 
+	/*
+	 * The node we allocated has no zone fallback lists. For avoiding
+	 * to access not-initialized zonelist, build here.
+	 */
+	mutex_lock(&zonelists_mutex);
+	build_all_zonelists(NULL);
+	mutex_unlock(&zonelists_mutex);
+
 	return pgdat;
 }
 
@@ -490,9 +521,9 @@ int mem_online_node(int nid)
 	pg_data_t	*pgdat;
 	int	ret;
 
-	lock_system_sleep();
+	lock_memory_hotplug();
 	pgdat = hotadd_new_pgdat(nid, 0);
-	if (pgdat) {
+	if (!pgdat) {
 		ret = -ENOMEM;
 		goto out;
 	}
@@ -501,7 +532,7 @@ int mem_online_node(int nid)
 	BUG_ON(ret);
 
 out:
-	unlock_system_sleep();
+	unlock_memory_hotplug();
 	return ret;
 }
 
@@ -513,7 +544,7 @@ int __ref add_memory(int nid, u64 start, u64 size)
 	struct resource *res;
 	int ret;
 
-	lock_system_sleep();
+	lock_memory_hotplug();
 
 	res = register_memory_resource(start, size);
 	ret = -EEXIST;
@@ -560,7 +591,7 @@ error:
 		release_memory_resource(res);
 
 out:
-	unlock_system_sleep();
+	unlock_memory_hotplug();
 	return ret;
 }
 EXPORT_SYMBOL_GPL(add_memory);
@@ -581,45 +612,32 @@ static inline int pageblock_free(struct page *page)
 /* Return the start of the next active pageblock after a given page */
 static struct page *next_active_pageblock(struct page *page)
 {
-	int pageblocks_stride;
-
 	/* Ensure the starting page is pageblock-aligned */
 	BUG_ON(page_to_pfn(page) & (pageblock_nr_pages - 1));
 
-	/* Move forward by at least 1 * pageblock_nr_pages */
-	pageblocks_stride = 1;
-
 	/* If the entire pageblock is free, move to the end of free page */
-	if (pageblock_free(page))
-		pageblocks_stride += page_order(page) - pageblock_order;
+	if (pageblock_free(page)) {
+		int order;
+		/* be careful. we don't have locks, page_order can be changed.*/
+		order = page_order(page);
+		if ((order < MAX_ORDER) && (order >= pageblock_order))
+			return page + (1 << order);
+	}
 
-	return page + (pageblocks_stride * pageblock_nr_pages);
+	return page + pageblock_nr_pages;
 }
 
 /* Checks if this range of memory is likely to be hot-removable. */
 int is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages)
 {
-	int type;
 	struct page *page = pfn_to_page(start_pfn);
 	struct page *end_page = page + nr_pages;
 
 	/* Check the starting page of each pageblock within the range */
 	for (; page < end_page; page = next_active_pageblock(page)) {
-		type = get_pageblock_migratetype(page);
-
-		/*
-		 * A pageblock containing MOVABLE or free pages is considered
-		 * removable
-		 */
-		if (type != MIGRATE_MOVABLE && !pageblock_free(page))
-			return 0;
-
-		/*
-		 * A pageblock starting with a PageReserved page is not
-		 * considered removable.
-		 */
-		if (PageReserved(page))
+		if (!is_pageblock_removable_nolock(page))
 			return 0;
+		cond_resched();
 	}
 
 	/* All pageblocks in the memory block are likely to be hot-removable */
@@ -656,7 +674,7 @@ 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.
  */
-int scan_lru_pages(unsigned long start, unsigned long end)
+static unsigned long scan_lru_pages(unsigned long start, unsigned long end)
 {
 	unsigned long pfn;
 	struct page *page;
@@ -692,7 +710,7 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
 		if (!pfn_valid(pfn))
 			continue;
 		page = pfn_to_page(pfn);
-		if (!page_count(page))
+		if (!get_page_unless_zero(page))
 			continue;
 		/*
 		 * We can skip free pages. And we can only deal with pages on
@@ -700,35 +718,39 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
 		 */
 		ret = isolate_lru_page(page);
 		if (!ret) { /* Success */
+			put_page(page);
 			list_add_tail(&page->lru, &source);
 			move_pages--;
 			inc_zone_page_state(page, NR_ISOLATED_ANON +
 					    page_is_file_cache(page));
 
 		} 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_ALERT "removing pfn %lx from LRU failed\n",
 			       pfn);
 			dump_page(page);
 #endif
+			put_page(page);
+			/* Because we don't have big zone->lock. we should
+			   check this again here. */
+			if (page_count(page)) {
+				not_managed++;
+				ret = -EBUSY;
+				break;
+			}
 		}
 	}
-	ret = -EBUSY;
-	if (not_managed) {
-		if (!list_empty(&source))
+	if (!list_empty(&source)) {
+		if (not_managed) {
+			putback_lru_pages(&source);
+			goto out;
+		}
+		/* this function returns # of failed pages */
+		ret = migrate_pages(&source, hotremove_migrate_alloc, 0,
+								true, true);
+		if (ret)
 			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, 1);
-
 out:
 	return ret;
 }
@@ -780,7 +802,7 @@ check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
 	return offlined;
 }
 
-static int offline_pages(unsigned long start_pfn,
+static int __ref offline_pages(unsigned long start_pfn,
 		  unsigned long end_pfn, unsigned long timeout)
 {
 	unsigned long pfn, nr_pages, expire;
@@ -800,7 +822,7 @@ static int offline_pages(unsigned long start_pfn,
 	if (!test_pages_in_a_zone(start_pfn, end_pfn))
 		return -EINVAL;
 
-	lock_system_sleep();
+	lock_memory_hotplug();
 
 	zone = page_zone(pfn_to_page(start_pfn));
 	node = zone_to_nid(zone);
@@ -837,7 +859,6 @@ repeat:
 	ret = 0;
 	if (drain) {
 		lru_add_drain_all();
-		flush_scheduled_work();
 		cond_resched();
 		drain_all_pages();
 	}
@@ -859,7 +880,6 @@ 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_pages();
@@ -880,8 +900,8 @@ repeat:
 	zone->zone_pgdat->node_present_pages -= offlined_pages;
 	totalram_pages -= offlined_pages;
 
-	setup_per_zone_wmarks();
-	calculate_zone_inactive_ratio(zone);
+	init_per_zone_wmark_min();
+
 	if (!node_present_pages(node)) {
 		node_clear_state(node, N_HIGH_MEMORY);
 		kswapd_stop(node);
@@ -891,7 +911,7 @@ repeat:
 	writeback_set_ratelimit();
 
 	memory_notify(MEM_OFFLINE, &arg);
-	unlock_system_sleep();
+	unlock_memory_hotplug();
 	return 0;
 
 failed_removal:
@@ -902,7 +922,7 @@ failed_removal:
 	undo_isolate_page_range(start_pfn, end_pfn);
 
 out:
-	unlock_system_sleep();
+	unlock_memory_hotplug();
 	return ret;
 }