[PATCH v1] mm/damon: guard THP-specific DAMOS actions with CONFIG_TRANSPARENT_HUGEPAGE
From: gutierrez.asier
Date: Sat Mar 14 2026 - 05:39:48 EST
From: Asier Gutierrez <gutierrez.asier@xxxxxxxxxxxxxxxxxxx>
MADV_HUGEPAGE and MADV_NOHUGEPAGE are guarded and they are not
available when compiling the kernel without TRANSPARENT_HUGEPAGE
option. Therefore, DAMOS_HUGEPAGE and DAMOS_NOHUGEPAGE shouldn't be
available to the user either.
Signed-off-by: Asier Gutierrez <gutierrez.asier@xxxxxxxxxxxxxxxxxxx>
---
Documentation/mm/damon/design.rst | 6 ++++--
include/linux/damon.h | 2 ++
mm/damon/sysfs-schemes.c | 2 ++
mm/damon/vaddr.c | 2 ++
4 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/Documentation/mm/damon/design.rst b/Documentation/mm/damon/design.rst
index 29fff20b3c2a..207219ee10d4 100644
--- a/Documentation/mm/damon/design.rst
+++ b/Documentation/mm/damon/design.rst
@@ -460,9 +460,11 @@ that supports each action are as below.
- ``pageout``: Reclaim the region.
Supported by ``vaddr``, ``fvaddr`` and ``paddr`` operations set.
- ``hugepage``: Call ``madvise()`` for the region with ``MADV_HUGEPAGE``.
- Supported by ``vaddr`` and ``fvaddr`` operations set.
+ Supported by ``vaddr`` and ``fvaddr`` operations set when
+ TRANSPARENT_HUGEPAGE is enabled.
- ``nohugepage``: Call ``madvise()`` for the region with ``MADV_NOHUGEPAGE``.
- Supported by ``vaddr`` and ``fvaddr`` operations set.
+ Supported by ``vaddr`` and ``fvaddr`` operations set when
+ TRANSPARENT_HUGEPAGE is enabled.
- ``lru_prio``: Prioritize the region on its LRU lists.
Supported by ``paddr`` operations set.
- ``lru_deprio``: Deprioritize the region on its LRU lists.
diff --git a/include/linux/damon.h b/include/linux/damon.h
index 3a441fbca170..b3fcbe84b5d7 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -138,8 +138,10 @@ enum damos_action {
DAMOS_WILLNEED,
DAMOS_COLD,
DAMOS_PAGEOUT,
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
DAMOS_HUGEPAGE,
DAMOS_NOHUGEPAGE,
+#endif
DAMOS_LRU_PRIO,
DAMOS_LRU_DEPRIO,
DAMOS_MIGRATE_HOT,
diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c
index 5186966dafb3..05e57c7ca2b6 100644
--- a/mm/damon/sysfs-schemes.c
+++ b/mm/damon/sysfs-schemes.c
@@ -2033,6 +2033,7 @@ static struct damos_sysfs_action_name damos_sysfs_action_names[] = {
.action = DAMOS_PAGEOUT,
.name = "pageout",
},
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
{
.action = DAMOS_HUGEPAGE,
.name = "hugepage",
@@ -2041,6 +2042,7 @@ static struct damos_sysfs_action_name damos_sysfs_action_names[] = {
.action = DAMOS_NOHUGEPAGE,
.name = "nohugepage",
},
+#endif
{
.action = DAMOS_LRU_PRIO,
.name = "lru_prio",
diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c
index b069dbc7e3d2..19c488660027 100644
--- a/mm/damon/vaddr.c
+++ b/mm/damon/vaddr.c
@@ -897,12 +897,14 @@ static unsigned long damon_va_apply_scheme(struct damon_ctx *ctx,
case DAMOS_PAGEOUT:
madv_action = MADV_PAGEOUT;
break;
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
case DAMOS_HUGEPAGE:
madv_action = MADV_HUGEPAGE;
break;
case DAMOS_NOHUGEPAGE:
madv_action = MADV_NOHUGEPAGE;
break;
+#endif
case DAMOS_MIGRATE_HOT:
case DAMOS_MIGRATE_COLD:
return damos_va_migrate(t, r, scheme, sz_filter_passed);
--
2.43.0