Re: assert/crash in __rmqueue() when enabling CONFIG_NUMA

From: Ingo Molnar
Date: Thu May 04 2006 - 05:09:09 EST



* Ingo Molnar <mingo@xxxxxxx> wrote:

> > The patch below isn't compile tested or correct for those cases where
> > alloc_remap is called or where arch code has allocated node_mem_map
> > for CONFIG_FLAT_NODE_MEM_MAP. It's just conveying what I believe the
> > issue is.
>
> thx. One pair of parentheses were missing i think - see the delta fix
> below. I'll try it.

the same easy crash still happens if i enable CONFIG_NUMA:

zone c214e600 (HighMem):
pfn: 00037d00
zone->zone_start_pfn: 00037e00
zone->spanned_pages: 00007e00
zone->zone_start_pfn + zone->spanned_pages: 0003fc00

[<c010574a>] do_invalid_op+0x63/0x93
[<c0104a0b>] error_code+0x4f/0x54
[<c0164d48>] get_page_from_freelist+0x13e/0x565
[<c01651dd>] __alloc_pages+0x6e/0x325
[<c017a6c9>] alloc_page_vma+0x80/0x86
[<c016e2ae>] __handle_mm_fault+0x1e7/0xd00
[<c10fe9af>] do_page_fault+0x339/0x7c5
[<c0104a0b>] error_code+0x4f/0x54

see the debug patch below.

Ingo

----
From: Ingo Molnar <mingo@xxxxxxx>

do buddy zone size checks unconditionally.

Signed-off-by: Ingo Molnar <mingo@xxxxxxx>

----

mm/page_alloc.c | 31 ++++++++++++++++++++++++-------
1 files changed, 24 insertions(+), 7 deletions(-)

Index: linux/mm/page_alloc.c
===================================================================
--- linux.orig/mm/page_alloc.c
+++ linux/mm/page_alloc.c
@@ -101,17 +101,32 @@ static int page_outside_zone_boundaries(
ret = 1;
} while (zone_span_seqretry(zone, seq));

+#define P(x) printk("%s: %08lx\n", #x, x)
+
+ if (ret) {
+ printk("zone %p (%s):\n", zone, zone->name);
+ P(pfn);
+ P(zone->zone_start_pfn);
+ P(zone->spanned_pages);
+ P(zone->zone_start_pfn + zone->spanned_pages);
+ }
+
return ret;
}

static int page_is_consistent(struct zone *zone, struct page *page)
{
-#ifdef CONFIG_HOLES_IN_ZONE
- if (!pfn_valid(page_to_pfn(page)))
+ if (!pfn_valid(page_to_pfn(page))) {
+ printk("BUG: pfn: %08lx, page: %p\n",
+ page_to_pfn(page), page);
+ dump_stack();
return 0;
-#endif
- if (zone != page_zone(page))
+ }
+ if (zone != page_zone(page)) {
+ printk("zone: %p != %p == page_zone(%p)\n",
+ zone, page_zone(page), page);
return 0;
+ }

return 1;
}
@@ -309,10 +324,12 @@ __find_combined_index(unsigned long page
*/
static inline int page_is_buddy(struct page *page, int order)
{
-#ifdef CONFIG_HOLES_IN_ZONE
- if (!pfn_valid(page_to_pfn(page)))
+ if (!pfn_valid(page_to_pfn(page))) {
+ printk("BUG: pfn: %08lx, page: %p, order: %d\n",
+ page_to_pfn(page), page, order);
+ dump_stack();
return 0;
-#endif
+ }

if (PageBuddy(page) && page_order(page) == order) {
BUG_ON(page_count(page) != 0);
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/