Save PG_compound or PG_head value in VMCOREINFO

[ptesarik@xxxxxxx (Petr Tesarik)]

To allow filtering of huge pages, makedumpfile must be able to identify
them in the dump. This can be done by checking for the appropriate
page flag, so communicate its value to makedumpfile through the VMCOREINFO 
interface.

Signed-off-by: Petr Tesarik <ptesarik at suse.cz>

---
 kernel/kexec.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -1511,6 +1511,11 @@ static int __init crash_save_vmcoreinfo_
 	VMCOREINFO_NUMBER(NR_FREE_PAGES);
 	VMCOREINFO_NUMBER(PG_lru);
 	VMCOREINFO_NUMBER(PG_private);
+#ifdef CONFIG_PAGEFLAGS_EXTENDED
+	VMCOREINFO_NUMBER(PG_head);
+#else
+	VMCOREINFO_NUMBER(PG_compound);
+#endif
 	VMCOREINFO_NUMBER(PG_swapcache);
 
 	arch_crash_save_vmcoreinfo();