On kernels from v2.6.18 to v2.6.37, buddy page is marked by the
PG_buddy flag.
kernel version | PG_buddy
------------------ +---------------------------------
v2.6.17 to v2.6.26 | 19
v2.6.27 to v2.6.37 | 19 if CONFIG_PAGEFLAGS_EXTEND=y
| 18 otherwise
We don't need to care about CONFIG_PAGEFLAGS_EXTEND because the
architectures specifying this as y are um and xtensa only. They are
not included in the supported architectures of makedumpfile.
Signed-off-by: HATAYAMA Daisuke <d.hatayama at jp.fujitsu.com>
---
makedumpfile.c | 24 ++++++++++++++++++++----
1 files changed, 20 insertions(+), 4 deletions(-)
diff --git a/makedumpfile.c b/makedumpfile.c
index 7b13dca..4e5d4d3 100644
--- a/makedumpfile.c
+++ b/makedumpfile.c
@@ -3669,6 +3669,19 @@ exclude_free_page(void)
}
/*
+ * For the kernel versions from v2.6.17 to v2.6.37.
+ */
+static int
+page_is_buddy_v2(unsigned long flags, unsigned int _mapcount,
+ unsigned long private, unsigned int _count)
+{
+ if (flags & (1UL << NUMBER(PG_buddy)))
+ return TRUE;
+
+ return FALSE;
+}
+
+/*
* For v2.6.38 and later kernel versions.
*/
static int
@@ -3690,10 +3703,13 @@ setup_page_is_buddy(void)
if (OFFSET(page.private) == NOT_FOUND_STRUCTURE)
goto out;
- if (NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE) != NOT_FOUND_NUMBER) {
- if (OFFSET(page._mapcount) != NOT_FOUND_STRUCTURE)
- info->page_is_buddy = page_is_buddy_v3;
- }
+ if (NUMBER(PG_buddy) == NOT_FOUND_NUMBER) {
+ if (NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE) != NOT_FOUND_NUMBER) {
+ if (OFFSET(page._mapcount) != NOT_FOUND_STRUCTURE)
+ info->page_is_buddy = page_is_buddy_v3;
+ }
+ } else
+ info->page_is_buddy = page_is_buddy_v2;
out:
if (!info->page_is_buddy)
