Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

[linux-2.6-microblaze.git] / mm / memory_hotplug.c

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 84ab329..55ac23e 100644 (file)
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -598,11 +598,6 @@ 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 generic_online_page(struct page *page, unsigned int order)
 {
        kernel_map_pages(page, 1 << order, 1);
@@ -1485,10 +1480,19 @@ 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;
@@ -1499,6 +1503,22 @@ static int __ref __offline_pages(unsigned long start_pfn,
 
        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,
@@ -1510,7 +1530,6 @@ static int __ref __offline_pages(unsigned long start_pfn,
 
        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,