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mm: verify the page links and memory model

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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>
This commit is contained in:
Mel Gorman
2008-07-23 21:26:51 -07:00
committed by Linus Torvalds
parent 6b74ab97bc
commit 708614e618
3 changed files with 91 additions and 0 deletions
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71
mm/mm_init.c
View File

@@ -7,9 +7,80 @@
*/
#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 %lu Node %lu Zone %lu\n",
(unsigned long)SECTIONS_PGSHIFT,
(unsigned long)NODES_PGSHIFT,
(unsigned long)ZONES_PGSHIFT);
mminit_dprintk(MMINIT_TRACE, "pageflags_layout_zoneid",
"Zone ID: %lu -> %lu\n",
(unsigned long)ZONEID_PGOFF,
(unsigned long)(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);