mm: print more details for bad_page()
bad_page() is cool in that it prints out a bunch of data about the page.
But, I can never remember which page flags are good and which are bad,
or whether ->index or ->mapping is required to be NULL.
This patch allows bad/dump_page() callers to specify a string about why
they are dumping the page and adds explanation strings to a number of
places. It also adds a 'bad_flags' argument to bad_page(), which it
then dumps out separately from the flags which are actually set.
This way, the messages will show specifically why the page was bad,
*specifically* which flags it is complaining about, if it was a page
flag combination which was the problem.
[akpm@linux-foundation.org: switch to pr_alert]
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c
index 07dbc8e..6e45a50 100644
--- a/mm/balloon_compaction.c
+++ b/mm/balloon_compaction.c
@@ -267,7 +267,7 @@
put_page(page);
} else {
WARN_ON(1);
- dump_page(page);
+ dump_page(page, "not movable balloon page");
}
unlock_page(page);
}
@@ -287,7 +287,7 @@
BUG_ON(!trylock_page(newpage));
if (WARN_ON(!__is_movable_balloon_page(page))) {
- dump_page(page);
+ dump_page(page, "not movable balloon page");
unlock_page(newpage);
return rc;
}