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mm: dump page when hitting a VM_BUG_ON using VM_BUG_ON_PAGE

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Most of the VM_BUG_ON assertions are performed on a page.  Usually, when
one of these assertions fails we'll get a BUG_ON with a call stack and
the registers.

I've recently noticed based on the requests to add a small piece of code
that dumps the page to various VM_BUG_ON sites that the page dump is
quite useful to people debugging issues in mm.

This patch adds a VM_BUG_ON_PAGE(cond, page) which beyond doing what
VM_BUG_ON() does, also dumps the page before executing the actual
BUG_ON.

[akpm@linux-foundation.org: fix up includes]
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Sasha Levin
2014-01-23 15:52:54 -08:00
committed by Linus Torvalds
parent e3bba3c3c9
commit 309381feae
30 changed files with 181 additions and 170 deletions
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21
mm/page_alloc.c
View File

@@ -509,12 +509,12 @@ static inline int page_is_buddy(struct page *page, struct page *buddy,
return 0;
if (page_is_guard(buddy) && page_order(buddy) == order) {
VM_BUG_ON(page_count(buddy) != 0);
VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
return 1;
}
if (PageBuddy(buddy) && page_order(buddy) == order) {
VM_BUG_ON(page_count(buddy) != 0);
VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
return 1;
}
return 0;
@@ -564,8 +564,8 @@ static inline void __free_one_page(struct page *page,
page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);
VM_BUG_ON(page_idx & ((1 << order) - 1));
VM_BUG_ON(bad_range(zone, page));
VM_BUG_ON_PAGE(page_idx & ((1 << order) - 1), page);
VM_BUG_ON_PAGE(bad_range(zone, page), page);
while (order < MAX_ORDER-1) {
buddy_idx = __find_buddy_index(page_idx, order);
@@ -827,7 +827,7 @@ static inline void expand(struct zone *zone, struct page *page,
area--;
high--;
size >>= 1;
VM_BUG_ON(bad_range(zone, &page[size]));
VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
#ifdef CONFIG_DEBUG_PAGEALLOC
if (high < debug_guardpage_minorder()) {
@@ -980,7 +980,7 @@ int move_freepages(struct zone *zone,
for (page = start_page; page <= end_page;) {
/* Make sure we are not inadvertently changing nodes */
VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone));
VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
if (!pfn_valid_within(page_to_pfn(page))) {
page++;
@@ -1429,8 +1429,8 @@ void split_page(struct page *page, unsigned int order)
{
int i;
VM_BUG_ON(PageCompound(page));
VM_BUG_ON(!page_count(page));
VM_BUG_ON_PAGE(PageCompound(page), page);
VM_BUG_ON_PAGE(!page_count(page), page);
#ifdef CONFIG_KMEMCHECK
/*
@@ -1577,7 +1577,7 @@ again:
zone_statistics(preferred_zone, zone, gfp_flags);
local_irq_restore(flags);
VM_BUG_ON(bad_range(zone, page));
VM_BUG_ON_PAGE(bad_range(zone, page), page);
if (prep_new_page(page, order, gfp_flags))
goto again;
return page;
@@ -6021,7 +6021,7 @@ void set_pageblock_flags_group(struct page *page, unsigned long flags,
pfn = page_to_pfn(page);
bitmap = get_pageblock_bitmap(zone, pfn);
bitidx = pfn_to_bitidx(zone, pfn);
VM_BUG_ON(!zone_spans_pfn(zone, pfn));
VM_BUG_ON_PAGE(!zone_spans_pfn(zone, pfn), page);
for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
if (flags & value)
@@ -6539,3 +6539,4 @@ void dump_page(struct page *page, char *reason)
{
dump_page_badflags(page, reason, 0);
}
EXPORT_SYMBOL_GPL(dump_page);