Merge branch 'master' of /pub/scm/linux/kernel/git/torvalds/linux-2.6

[karo-tx-linux.git] / mm / memory_hotplug.c

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index d4e940a26945cde1f8251b39b37fde3144639d5b..2c6523af54738faba3dd37eef938315503275de4 100644 (file)
--- 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)
 {
@@ -493,7 +510,7 @@ 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) {
                ret = -ENOMEM;
@@ -504,7 +521,7 @@ int mem_online_node(int nid)
        BUG_ON(ret);
 
 out:
-       unlock_system_sleep();
+       unlock_memory_hotplug();
        return ret;
 }
 
@@ -516,7 +533,7 @@ 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;
@@ -563,7 +580,7 @@ error:
                release_memory_resource(res);
 
 out:
-       unlock_system_sleep();
+       unlock_memory_hotplug();
        return ret;
 }
 EXPORT_SYMBOL_GPL(add_memory);
@@ -602,27 +619,14 @@ static struct page *next_active_pageblock(struct page *page)
 /* 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 */
@@ -659,7 +663,7 @@ 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;
@@ -709,29 +713,30 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
                                            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
+                       /* Becasue 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, 1);
+               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;
 }
@@ -803,7 +808,7 @@ 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);
@@ -892,7 +897,7 @@ repeat:
        writeback_set_ratelimit();
 
        memory_notify(MEM_OFFLINE, &arg);
-       unlock_system_sleep();
+       unlock_memory_hotplug();
        return 0;
 
 failed_removal:
@@ -903,7 +908,7 @@ failed_removal:
        undo_isolate_page_range(start_pfn, end_pfn);
 
 out:
-       unlock_system_sleep();
+       unlock_memory_hotplug();
        return ret;
 }