[PATCH] mm: vmalloc: add optimization hint on page existence check

From: Miao Wang via B4 Relay
Date: Tue Aug 13 2024 - 13:12:25 EST


From: Miao Wang <shankerwangmiao@xxxxxxxxx>

In commit 21e516b913c1 ("mm: vmalloc: dump page owner info if page is
already mapped"), a BUG_ON macro was changed into an if statement, where
the compiler optimization hint introduced in the BUG_ON macro was removed
along with this change. This patch adds back the hint.

Fixes: 21e516b913c1 ("mm: vmalloc: dump page owner info if page is already mapped")
Signed-off-by: Miao Wang <shankerwangmiao@xxxxxxxxx>
---
mm/vmalloc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 6b783baf12a1..5d031fc83f04 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -105,7 +105,7 @@ static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
if (!pte)
return -ENOMEM;
do {
- if (!pte_none(ptep_get(pte))) {
+ if (unlikely(!pte_none(ptep_get(pte)))) {
if (pfn_valid(pfn)) {
page = pfn_to_page(pfn);
dump_page(page, "remapping already mapped page");

---
base-commit: 7c626ce4bae1ac14f60076d00eafe71af30450ba
change-id: 20240814-fix_vmap_unlikely-2973d2cb904b

Best regards,
--
Miao Wang <shankerwangmiao@xxxxxxxxx>