The patch titled
mm: verify the page links and memory model
has been added to the -mm tree. Its filename is
mm-verify-the-page-links-and-memory-model.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: mm: verify the page links and memory model
From: Mel Gorman <mel@xxxxxxxxx>
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.
Signed-off-by: Mel Gorman <mel@xxxxxxxxx>
Cc: Christoph Lameter <clameter@xxxxxxx>
Cc: Andy Whitcroft <apw@xxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/internal.h | 12 +++++++
mm/mm_init.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++
mm/page_alloc.c | 6 +++
3 files changed, 88 insertions(+)
diff -puN mm/internal.h~mm-verify-the-page-links-and-memory-model mm/internal.h
--- a/mm/internal.h~mm-verify-the-page-links-and-memory-model
+++ a/mm/internal.h
@@ -78,6 +78,10 @@ do { \
} \
} while (0)
+extern void mminit_verify_pageflags_layout(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_dprintk(enum mminit_level level,
@@ -85,5 +89,13 @@ static inline void mminit_dprintk(enum m
{
}
+static inline void mminit_verify_pageflags_layout(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 -puN mm/mm_init.c~mm-verify-the-page-links-and-memory-model mm/mm_init.c
--- a/mm/mm_init.c~mm-verify-the-page-links-and-memory-model
+++ a/mm/mm_init.c
@@ -7,9 +7,79 @@
*/
#include <linux/kernel.h>
#include <linux/init.h>
+#include "internal.h"
int __meminitdata mminit_loglevel;
+void __init mminit_verify_pageflags_layout(void)
+{
+ int shift, width;
+ unsigned long or_mask, add_mask;
+
+ shift = 8 * sizeof(unsigned long);
+ width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH;
+ mminit_dprintk(MMINIT_TRACE, "pageflags_layout_widths",
+ "Section %d Node %d Zone %d Flags %d\n",
+ SECTIONS_WIDTH,
+ NODES_WIDTH,
+ ZONES_WIDTH,
+ NR_PAGEFLAGS);
+ mminit_dprintk(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_dprintk(MMINIT_TRACE, "pageflags_layout_offsets",
+ "Section %d Node %d Zone %d\n",
+ SECTIONS_PGSHIFT,
+ NODES_PGSHIFT,
+ ZONES_PGSHIFT);
+ mminit_dprintk(MMINIT_TRACE, "pageflags_layout_zoneid",
+ "Zone ID: %d -> %d\n",
+ ZONEID_PGOFF, ZONEID_PGOFF + ZONEID_SHIFT);
+ mminit_dprintk(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_dprintk(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);
+ }
+
+ /* Check for bitmask overlaps */
+ or_mask = (ZONES_MASK << ZONES_PGSHIFT) |
+ (NODES_MASK << NODES_PGSHIFT) |
+ (SECTIONS_MASK << SECTIONS_PGSHIFT);
+ add_mask = (ZONES_MASK << ZONES_PGSHIFT) +
+ (NODES_MASK << NODES_PGSHIFT) +
+ (SECTIONS_MASK << SECTIONS_PGSHIFT);
+ BUG_ON(or_mask != add_mask);
+}
+
+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 -puN mm/page_alloc.c~mm-verify-the-page-links-and-memory-model mm/page_alloc.c
--- a/mm/page_alloc.c~mm-verify-the-page-links-and-memory-model
+++ a/mm/page_alloc.c
@@ -2554,6 +2554,7 @@ 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);
SetPageReserved(page);
@@ -2856,6 +2857,10 @@ __meminit int init_currently_empty_zone(
zone->zone_start_pfn = zone_start_pfn;
+ mminit_dprintk(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);
@@ -3923,6 +3928,7 @@ void __init free_area_init_nodes(unsigne
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);
_
Patches currently in -mm which might be from mel@xxxxxxxxx are
origin.patch
mm-fix-usemap-initialization.patch
mm-fix-misleading-__gfp_repeat-related-comments.patch
page-allcoator-smarter-retry-of-costly-order-allocations.patch
page-allocator-explicitly-retry-hugepage-allocations.patch
memcgroup-move-memory-controller-allocations-to-their-own-slabs.patch
proc-pagetypeinfo-fix-output-for-memoryless-nodes.patch
mm-add-a-basic-debugging-framework-for-memory-initialisation.patch
mm-verify-the-page-links-and-memory-model.patch
mm-make-defensive-checks-around-pfn-values-registered-for-memory-usage.patch
mm-print-out-the-zonelists-on-request-for-manual-verification.patch
page-owner-tracking-leak-detector.patch
add-debugging-aid-for-memory-initialisation-problems.patch
--
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