This patch prints 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. The final check made with respect to
pages is that pfn_to_page() and page_to_pfn() are returning sensible values.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
---
mm/internal.h | 12 +++++++++
mm/mm_init.c | 63 +++++++++++++++++++++++++++++++++++++++++++++++++++
mm/page_alloc.c | 6 ++++
3 files changed, 81 insertions(+)
diff -rup -X /usr/src/patchset-0.6/bin//dontdiff linux-2.6.25-mm1-0010_mminit_debug_framework/mm/internal.h linux-2.6.25-mm1-0020_memmap_init_debug/mm/internal.h
--- linux-2.6.25-mm1-0010_mminit_debug_framework/mm/internal.h 2008-04-22 17:47:13.000000000 +0100
+++ linux-2.6.25-mm1-0020_memmap_init_debug/mm/internal.h 2008-04-22 17:49:33.000000000 +0100
@@ -77,6 +77,10 @@ do { \
} \
} while (0)
+extern void mminit_verify_pageflags(void);
+extern void mminit_verify_page_links(struct page *page,
+ enum zone_type zone, unsigned long nid, unsigned long pfn);
+
#else
static inline void mminit_debug_printk(unsigned int level, const char *prefix,
@@ -84,5 +88,13 @@ static inline void mminit_debug_printk(u
{
}
+static inline void mminit_verify_pageflags(void)
+{
+}
+
+static inline void mminit_verify_page_links(struct page *page,
+ enum zone_type zone, unsigned long nid, unsigned long pfn)
+{
+}
#endif /* CONFIG_DEBUG_MEMORY_INIT */
#endif
diff -rup -X /usr/src/patchset-0.6/bin//dontdiff linux-2.6.25-mm1-0010_mminit_debug_framework/mm/mm_init.c linux-2.6.25-mm1-0020_memmap_init_debug/mm/mm_init.c
--- linux-2.6.25-mm1-0010_mminit_debug_framework/mm/mm_init.c 2008-04-22 17:47:13.000000000 +0100
+++ linux-2.6.25-mm1-0020_memmap_init_debug/mm/mm_init.c 2008-04-22 17:49:33.000000000 +0100
@@ -7,9 +7,72 @@
*/
#include <linux/kernel.h>
#include <linux/init.h>
+#include "internal.h"
int __meminitdata mminit_loglevel;
+void __init mminit_verify_pageflags(void)
+{
+ int shift, width;
+
+ shift = 8 * sizeof(unsigned long);
+ width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH;
+ mminit_debug_printk(MMINIT_TRACE, "pageflags_layout_widths",
+ "Section %d Node %d Zone %d Flags %d\n",
+ SECTIONS_WIDTH,
+ NODES_WIDTH,
+ ZONES_WIDTH,
+ NR_PAGEFLAGS);
+ mminit_debug_printk(MMINIT_TRACE, "pageflags_layout_shifts",
+ "Section %d Node %d Zone %d\n",
+#ifdef SECTIONS_SHIFT
+ SECTIONS_SHIFT,
+#else
+ 0,
+#endif
+ NODES_SHIFT,
+ ZONES_SHIFT);
+ mminit_debug_printk(MMINIT_TRACE, "pageflags_layout_offsets",
+ "Section %d Node %d Zone %d\n",
+ SECTIONS_PGSHIFT,
+ NODES_PGSHIFT,
+ ZONES_PGSHIFT);
+ mminit_debug_printk(MMINIT_TRACE, "pageflags_layout_zoneid",
+ "Zone ID: %d -> %d\n",
+ ZONEID_PGOFF, ZONEID_PGOFF + ZONEID_SHIFT);
+ mminit_debug_printk(MMINIT_TRACE, "pageflags_layout_usage",
+ "location: %d -> %d unused %d -> %d flags %d -> %d\n",
+ shift, width, width, NR_PAGEFLAGS, NR_PAGEFLAGS, 0);
+#ifdef NODE_NOT_IN_PAGE_FLAGS
+ mminit_debug_printk(MMINIT_TRACE, "pageflags_layout_nodeflags",
+ "Node not in page flags");
+#endif
+
+ if (SECTIONS_WIDTH) {
+ shift -= SECTIONS_WIDTH;
+ BUG_ON(shift != SECTIONS_PGSHIFT);
+ }
+ if (NODES_WIDTH) {
+ shift -= NODES_WIDTH;
+ BUG_ON(shift != NODES_PGSHIFT);
+ }
+ if (ZONES_WIDTH) {
+ shift -= ZONES_WIDTH;
+ BUG_ON(shift != ZONES_PGSHIFT);
+ }
+ BUG_ON((ZONES_MASK << ZONES_PGSHIFT) &
+ (NODES_MASK << NODES_PGSHIFT) &
+ (SECTIONS_MASK << SECTIONS_PGSHIFT));
+}
+
+void __meminit mminit_verify_page_links(struct page *page, enum zone_type zone,
+ unsigned long nid, unsigned long pfn)
+{
+ BUG_ON(page_to_nid(page) != nid);
+ BUG_ON(page_zonenum(page) != zone);
+ BUG_ON(page_to_pfn(page) != pfn);
+}
+
static __init int set_mminit_loglevel(char *str)
{
get_option(&str, &mminit_loglevel);
diff -rup -X /usr/src/patchset-0.6/bin//dontdiff linux-2.6.25-mm1-0010_mminit_debug_framework/mm/page_alloc.c linux-2.6.25-mm1-0020_memmap_init_debug/mm/page_alloc.c
--- linux-2.6.25-mm1-0010_mminit_debug_framework/mm/page_alloc.c 2008-04-22 17:47:13.000000000 +0100
+++ linux-2.6.25-mm1-0020_memmap_init_debug/mm/page_alloc.c 2008-04-22 17:49:33.000000000 +0100
@@ -2637,6 +2637,7 @@ void __meminit memmap_init_zone(unsigned
}
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);
pc = page_get_page_cgroup(page);
@@ -2939,6 +2940,10 @@ __meminit int init_currently_empty_zone(
zone->zone_start_pfn = zone_start_pfn;
+ mminit_debug_printk(MMINIT_TRACE, "memmap_init",
+ "Initialising map node %d zone %d pfns %lu -> %lu\n",
+ pgdat->node_id, zone_idx(zone),
+ zone_start_pfn, (zone_start_pfn + size));
memmap_init(size, pgdat->node_id, zone_idx(zone), zone_start_pfn);
zone_init_free_lists(zone);
@@ -4012,6 +4017,7 @@ void __init free_area_init_nodes(unsigne
early_node_map[i].end_pfn);
/* Initialise every node */
+ mminit_verify_pageflags();
setup_nr_node_ids();
for_each_online_node(nid) {
pg_data_t *pgdat = NODE_DATA(nid);
--
