mm: verify the page links and memory model

Print out information on how the page flags are being used if mminit_loglevel
is MMINIT_VERIFY or higher and unconditionally performs sanity checks on the
flags regardless of loglevel.

When the page flags are updated with section, node and zone information, a
check are made to ensure the values can be retrieved correctly.  Finally we
confirm that pfn_to_page and page_to_pfn are the correct inverse functions.

[akpm@linux-foundation.org: fix printk warnings]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 0908352ba727..acab6ad326df 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2534,6 +2534,7 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
                 }
                 page = pfn_to_page(pfn);
                 set_page_links(page, zone, nid, pfn);
+                mminit_verify_page_links(page, zone, nid, pfn);
                 init_page_count(page);
                 reset_page_mapcount(page);
                 SetPageReserved(page);
@@ -2836,6 +2837,12 @@ __meminit int init_currently_empty_zone(struct zone *zone,
 
         zone->zone_start_pfn = zone_start_pfn;
 
+        mminit_dprintk(MMINIT_TRACE, "memmap_init",
+                        "Initialising map node %d zone %lu pfns %lu -> %lu\n",
+                        pgdat->node_id,
+                        (unsigned long)zone_idx(zone),
+                        zone_start_pfn, (zone_start_pfn + size));
+
         zone_init_free_lists(zone);
 
         return 0;
@@ -3961,6 +3968,7 @@ void __init free_area_init_nodes(unsigned long *max_zone_pfn)
                                                 early_node_map[i].end_pfn);
 
         /* Initialise every node */
+        mminit_verify_pageflags_layout();
         setup_nr_node_ids();
         for_each_online_node(nid) {
                 pg_data_t *pgdat = NODE_DATA(nid);