Thread (8 messages) 8 messages, 3 authors, 2016-04-04
STALE3767d

[PATCH 3/4] page-flags: make page flag helpers accept struct head_page

From: Kirill A. Shutemov <hidden>
Date: 2016-03-27 19:47:51
Also in: lkml
Subsystem: kernel build + files below scripts/ (unless maintained elsewhere), the rest · Maintainers: Nathan Chancellor, Nicolas Schier, Linus Torvalds

This patch makes all generated page flag helpers to accept pointer to
struct head_page as well as struct page.

In case if pointer to struct head_page is passed, we assume that it's
head page and bypass policy constrain checks.

Note, to get get inteface consistent we would need to make non-generated
page flag helper to accept struct head_page as well.

Not-yet-signed-off-by: Kirill A. Shutemov [off-list ref]
---
 scripts/mkpageflags.sh | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/scripts/mkpageflags.sh b/scripts/mkpageflags.sh
index 29d46bccaea4..272aab4ad1a3 100755
--- a/scripts/mkpageflags.sh
+++ b/scripts/mkpageflags.sh
@@ -6,23 +6,23 @@ fatal() {
 }
 
 any() {
-	echo "(__p)"
+	echo "((struct page *)(__p))"
 }
 
 head() {
-	echo "compound_head(__p)"
+	echo "compound_head((struct page *)(__p))"
 }
 
 no_tail() {
 	local enforce="${1:+VM_BUG_ON_PGFLAGS(PageTail(__p), __p);}"
 
-	echo "({$enforce compound_head(__p);})"
+	echo "({$enforce compound_head((struct page *)(__p));})"
 }
 
 no_compound() {
 	local enforce="${1:+VM_BUG_ON_PGFLAGS(PageCompound(__p), __p);}"
 
-	echo "({$enforce __p;})"
+	echo "({$enforce ((struct page *)(__p));})"
 }
 
 generate_test() {
@@ -34,7 +34,9 @@ generate_test() {
 	cat <<EOF
 #define $uname(__p) ({								\\
 	int ret;								\\
-	if (__builtin_types_compatible_p(typeof(*(__p)), struct page))		\\
+	if (__builtin_types_compatible_p(typeof(*(__p)), struct head_page))	\\
+		ret = $op(PG_$lname, &((struct head_page *)(__p))->page.flags);	\\
+	else if (__builtin_types_compatible_p(typeof(*(__p)), struct page))	\\
 		ret = $op(PG_$lname, &$page->flags);				\\
 	else									\\
 		BUILD_BUG();							\\
@@ -52,7 +54,9 @@ generate_mod() {
 
 	cat <<EOF
 #define $uname(__p) do {							\\
-	if (__builtin_types_compatible_p(typeof(*(__p)), struct page))		\\
+	if (__builtin_types_compatible_p(typeof(*(__p)), struct head_page))	\\
+		$op(PG_$lname, &((struct head_page *)(__p))->page.flags);	\\
+	else if (__builtin_types_compatible_p(typeof(*(__p)), struct page))	\\
 		$op(PG_$lname, &$page->flags);					\\
 	else									\\
 		BUILD_BUG();							\\
-- 
2.8.0.rc3

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