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-rw-r--r--mm/page_alloc.c102
1 files changed, 72 insertions, 30 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 533e2147d14f..e3758a09a009 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -205,7 +205,7 @@ static char * const zone_names[MAX_NR_ZONES] = {
};
int min_free_kbytes = 1024;
-int user_min_free_kbytes;
+int user_min_free_kbytes = -1;
static unsigned long __meminitdata nr_kernel_pages;
static unsigned long __meminitdata nr_all_pages;
@@ -295,7 +295,7 @@ static inline int bad_range(struct zone *zone, struct page *page)
}
#endif
-static void bad_page(struct page *page)
+static void bad_page(struct page *page, char *reason, unsigned long bad_flags)
{
static unsigned long resume;
static unsigned long nr_shown;
@@ -329,7 +329,7 @@ static void bad_page(struct page *page)
printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n",
current->comm, page_to_pfn(page));
- dump_page(page);
+ dump_page_badflags(page, reason, bad_flags);
print_modules();
dump_stack();
@@ -383,7 +383,7 @@ static int destroy_compound_page(struct page *page, unsigned long order)
int bad = 0;
if (unlikely(compound_order(page) != order)) {
- bad_page(page);
+ bad_page(page, "wrong compound order", 0);
bad++;
}
@@ -392,8 +392,11 @@ static int destroy_compound_page(struct page *page, unsigned long order)
for (i = 1; i < nr_pages; i++) {
struct page *p = page + i;
- if (unlikely(!PageTail(p) || (p->first_page != page))) {
- bad_page(page);
+ if (unlikely(!PageTail(p))) {
+ bad_page(page, "PageTail not set", 0);
+ bad++;
+ } else if (unlikely(p->first_page != page)) {
+ bad_page(page, "first_page not consistent", 0);
bad++;
}
__ClearPageTail(p);
@@ -506,12 +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;
@@ -561,8 +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);
@@ -618,12 +621,23 @@ out:
static inline int free_pages_check(struct page *page)
{
- if (unlikely(page_mapcount(page) |
- (page->mapping != NULL) |
- (atomic_read(&page->_count) != 0) |
- (page->flags & PAGE_FLAGS_CHECK_AT_FREE) |
- (mem_cgroup_bad_page_check(page)))) {
- bad_page(page);
+ char *bad_reason = NULL;
+ unsigned long bad_flags = 0;
+
+ if (unlikely(page_mapcount(page)))
+ bad_reason = "nonzero mapcount";
+ if (unlikely(page->mapping != NULL))
+ bad_reason = "non-NULL mapping";
+ if (unlikely(atomic_read(&page->_count) != 0))
+ bad_reason = "nonzero _count";
+ if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) {
+ bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
+ bad_flags = PAGE_FLAGS_CHECK_AT_FREE;
+ }
+ if (unlikely(mem_cgroup_bad_page_check(page)))
+ bad_reason = "cgroup check failed";
+ if (unlikely(bad_reason)) {
+ bad_page(page, bad_reason, bad_flags);
return 1;
}
page_cpupid_reset_last(page);
@@ -813,7 +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()) {
@@ -843,12 +857,23 @@ static inline void expand(struct zone *zone, struct page *page,
*/
static inline int check_new_page(struct page *page)
{
- if (unlikely(page_mapcount(page) |
- (page->mapping != NULL) |
- (atomic_read(&page->_count) != 0) |
- (page->flags & PAGE_FLAGS_CHECK_AT_PREP) |
- (mem_cgroup_bad_page_check(page)))) {
- bad_page(page);
+ char *bad_reason = NULL;
+ unsigned long bad_flags = 0;
+
+ if (unlikely(page_mapcount(page)))
+ bad_reason = "nonzero mapcount";
+ if (unlikely(page->mapping != NULL))
+ bad_reason = "non-NULL mapping";
+ if (unlikely(atomic_read(&page->_count) != 0))
+ bad_reason = "nonzero _count";
+ if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) {
+ bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";
+ bad_flags = PAGE_FLAGS_CHECK_AT_PREP;
+ }
+ if (unlikely(mem_cgroup_bad_page_check(page)))
+ bad_reason = "cgroup check failed";
+ if (unlikely(bad_reason)) {
+ bad_page(page, bad_reason, bad_flags);
return 1;
}
return 0;
@@ -955,7 +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++;
@@ -1404,8 +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
/*
@@ -1552,7 +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;
@@ -5729,7 +5754,12 @@ module_init(init_per_zone_wmark_min)
int min_free_kbytes_sysctl_handler(ctl_table *table, int write,
void __user *buffer, size_t *length, loff_t *ppos)
{
- proc_dointvec(table, write, buffer, length, ppos);
+ int rc;
+
+ rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
+ if (rc)
+ return rc;
+
if (write) {
user_min_free_kbytes = min_free_kbytes;
setup_per_zone_wmarks();
@@ -5996,7 +6026,7 @@ 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)
@@ -6494,12 +6524,24 @@ static void dump_page_flags(unsigned long flags)
printk(")\n");
}
-void dump_page(struct page *page)
+void dump_page_badflags(struct page *page, char *reason, unsigned long badflags)
{
printk(KERN_ALERT
"page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
page, atomic_read(&page->_count), page_mapcount(page),
page->mapping, page->index);
dump_page_flags(page->flags);
+ if (reason)
+ pr_alert("page dumped because: %s\n", reason);
+ if (page->flags & badflags) {
+ pr_alert("bad because of flags:\n");
+ dump_page_flags(page->flags & badflags);
+ }
mem_cgroup_print_bad_page(page);
}
+
+void dump_page(struct page *page, char *reason)
+{
+ dump_page_badflags(page, reason, 0);
+}
+EXPORT_SYMBOL_GPL(dump_page);
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-07-19 14:20:27 +0200