mm: introduce dump_page() and print symbolic flag names
- introduce dump_page() to print the page info for debugging some error
condition.
- convert three mm users: bad_page(), print_bad_pte() and memory offline
failure.
- print an extra field: the symbolic names of page->flags
Example dump_page() output:
[ 157.521694] page:ffffea0000a7cba8 count:2 mapcount:1 mapping:ffff88001c901791 index:0x147
[ 157.525570] page flags: 0x100000000100068(uptodate|lru|active|swapbacked)
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alex Chiang <achiang@hp.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Mel Gorman <mel@linux.vnet.ibm.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 78ce90d..d03c946 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -50,6 +50,7 @@
#include <linux/kmemleak.h>
#include <linux/memory.h>
#include <trace/events/kmem.h>
+#include <linux/ftrace_event.h>
#include <asm/tlbflush.h>
#include <asm/div64.h>
@@ -288,10 +289,7 @@
printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n",
current->comm, page_to_pfn(page));
- printk(KERN_ALERT
- "page:%p flags:%p count:%d mapcount:%d mapping:%p index:%lx\n",
- page, (void *)page->flags, page_count(page),
- page_mapcount(page), page->mapping, page->index);
+ dump_page(page);
dump_stack();
out:
@@ -5183,3 +5181,80 @@
return order < MAX_ORDER;
}
#endif
+
+static struct trace_print_flags pageflag_names[] = {
+ {1UL << PG_locked, "locked" },
+ {1UL << PG_error, "error" },
+ {1UL << PG_referenced, "referenced" },
+ {1UL << PG_uptodate, "uptodate" },
+ {1UL << PG_dirty, "dirty" },
+ {1UL << PG_lru, "lru" },
+ {1UL << PG_active, "active" },
+ {1UL << PG_slab, "slab" },
+ {1UL << PG_owner_priv_1, "owner_priv_1" },
+ {1UL << PG_arch_1, "arch_1" },
+ {1UL << PG_reserved, "reserved" },
+ {1UL << PG_private, "private" },
+ {1UL << PG_private_2, "private_2" },
+ {1UL << PG_writeback, "writeback" },
+#ifdef CONFIG_PAGEFLAGS_EXTENDED
+ {1UL << PG_head, "head" },
+ {1UL << PG_tail, "tail" },
+#else
+ {1UL << PG_compound, "compound" },
+#endif
+ {1UL << PG_swapcache, "swapcache" },
+ {1UL << PG_mappedtodisk, "mappedtodisk" },
+ {1UL << PG_reclaim, "reclaim" },
+ {1UL << PG_buddy, "buddy" },
+ {1UL << PG_swapbacked, "swapbacked" },
+ {1UL << PG_unevictable, "unevictable" },
+#ifdef CONFIG_MMU
+ {1UL << PG_mlocked, "mlocked" },
+#endif
+#ifdef CONFIG_ARCH_USES_PG_UNCACHED
+ {1UL << PG_uncached, "uncached" },
+#endif
+#ifdef CONFIG_MEMORY_FAILURE
+ {1UL << PG_hwpoison, "hwpoison" },
+#endif
+ {-1UL, NULL },
+};
+
+static void dump_page_flags(unsigned long flags)
+{
+ const char *delim = "";
+ unsigned long mask;
+ int i;
+
+ printk(KERN_ALERT "page flags: %#lx(", flags);
+
+ /* remove zone id */
+ flags &= (1UL << NR_PAGEFLAGS) - 1;
+
+ for (i = 0; pageflag_names[i].name && flags; i++) {
+
+ mask = pageflag_names[i].mask;
+ if ((flags & mask) != mask)
+ continue;
+
+ flags &= ~mask;
+ printk("%s%s", delim, pageflag_names[i].name);
+ delim = "|";
+ }
+
+ /* check for left over flags */
+ if (flags)
+ printk("%s%#lx", delim, flags);
+
+ printk(")\n");
+}
+
+void dump_page(struct page *page)
+{
+ printk(KERN_ALERT
+ "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
+ page, page_count(page), page_mapcount(page),
+ page->mapping, page->index);
+ dump_page_flags(page->flags);
+}