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From: Xie Yuanbin <qq570070308@gmail.com>
To: rppt@kernel.org, david.laight.linux@gmail.com,
	akpm@linux-foundation.org, david@kernel.org, ljs@kernel.org,
	Liam.Howlett@oracle.com, vbabka@kernel.org, surenb@google.com,
	mhocko@suse.com, nathan@kernel.org,
	nick.desaulniers+lkml@gmail.com, morbo@google.com,
	justinstitt@google.com
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	llvm@lists.linux.dev, Xie Yuanbin <qq570070308@gmail.com>
Subject: [PATCH] mm/debug: optimize once judgment with clang
Date: Mon,  9 Mar 2026 23:34:05 +0800	[thread overview]
Message-ID: <20260309153405.20130-1-qq570070308@gmail.com> (raw)

commit 242b872239f6a7deacbc ("include/linux/once_lite.h: fix judgment in
WARN_ONCE with clang") helps optimize performance and size under the
clang compiler, but the modification is not complete.

Port the modification to VM_WARN_ON_ONCE_PAGE(), VM_WARN_ON_ONCE_FOLIO(),
VM_WARN_ON_ONCE_MM() and VM_WARN_ON_ONCE_VMA().

Cc: Mike Rapoport <rppt@kernel.org>
Cc: David Laight <david.laight.linux@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Xie Yuanbin <qq570070308@gmail.com>
---
 include/linux/mmdebug.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/linux/mmdebug.h b/include/linux/mmdebug.h
index ab60ffba08f5..a167c5aa525e 100644
--- a/include/linux/mmdebug.h
+++ b/include/linux/mmdebug.h
@@ -60,7 +60,7 @@ void vma_iter_dump_tree(const struct vma_iterator *vmi);
 	static bool __section(".data..once") __warned;			\
 	int __ret_warn_once = !!(cond);					\
 									\
-	if (unlikely(__ret_warn_once && !__warned)) {			\
+	if (unlikely(__ret_warn_once) && unlikely(!__warned)) {		\
 		dump_page(page, "VM_WARN_ON_ONCE_PAGE(" __stringify(cond)")");\
 		__warned = true;					\
 		WARN_ON(1);						\
@@ -80,7 +80,7 @@ void vma_iter_dump_tree(const struct vma_iterator *vmi);
 	static bool __section(".data..once") __warned;			\
 	int __ret_warn_once = !!(cond);					\
 									\
-	if (unlikely(__ret_warn_once && !__warned)) {			\
+	if (unlikely(__ret_warn_once) && unlikely(!__warned)) {		\
 		dump_page(&folio->page, "VM_WARN_ON_ONCE_FOLIO(" __stringify(cond)")");\
 		__warned = true;					\
 		WARN_ON(1);						\
@@ -91,7 +91,7 @@ void vma_iter_dump_tree(const struct vma_iterator *vmi);
 	static bool __section(".data..once") __warned;			\
 	int __ret_warn_once = !!(cond);					\
 									\
-	if (unlikely(__ret_warn_once && !__warned)) {			\
+	if (unlikely(__ret_warn_once) && unlikely(!__warned)) {		\
 		dump_mm(mm);						\
 		__warned = true;					\
 		WARN_ON(1);						\
@@ -102,7 +102,7 @@ void vma_iter_dump_tree(const struct vma_iterator *vmi);
 	static bool __section(".data..once") __warned;			\
 	int __ret_warn_once = !!(cond);					\
 									\
-	if (unlikely(__ret_warn_once && !__warned)) {			\
+	if (unlikely(__ret_warn_once) && unlikely(!__warned)) {		\
 		dump_vma(vma);						\
 		__warned = true;					\
 		WARN_ON(1);						\
-- 
2.53.0



             reply	other threads:[~2026-03-09 15:35 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-03-09 15:34 Xie Yuanbin [this message]
2026-03-10 10:50 ` [PATCH] mm/debug: optimize once judgment with clang vbabka

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