[PATCH v4 16/18] mm: remove the __GFP_NO_OBJ_EXT flag

From: Brendan Jackman

Date: Thu Jul 02 2026 - 06:14:46 EST


From: "Vlastimil Babka (SUSE)" <vbabka@xxxxxxxxxx>

All users of the flag are converted to SLAB_ALLOC_NO_RECURSE or
ALLOC_NO_CODETAG (from __GFP_NO_CODETAG which reused the NO_OBJ_EXT bit).
Free up the flag bit.

Signed-off-by: Vlastimil Babka (SUSE) <vbabka@xxxxxxxxxx>
[Rebased onto __GFP_NO_CODETAG removal]
Signed-off-by: Brendan Jackman <jackmanb@xxxxxxxxxx>
---
include/linux/gfp_types.h | 7 -------
include/trace/events/mmflags.h | 10 +---------
tools/include/linux/gfp_types.h | 7 -------
3 files changed, 1 insertion(+), 23 deletions(-)

diff --git a/include/linux/gfp_types.h b/include/linux/gfp_types.h
index 463b551d12d99..190191411009f 100644
--- a/include/linux/gfp_types.h
+++ b/include/linux/gfp_types.h
@@ -55,7 +55,6 @@ enum {
#ifdef CONFIG_LOCKDEP
___GFP_NOLOCKDEP_BIT,
#endif
- ___GFP_NO_OBJ_EXT_BIT,
___GFP_LAST_BIT
};

@@ -96,7 +95,6 @@ enum {
#else
#define ___GFP_NOLOCKDEP 0
#endif
-#define ___GFP_NO_OBJ_EXT BIT(___GFP_NO_OBJ_EXT_BIT)

/*
* Physical address zone modifiers (see linux/mmzone.h - low four bits)
@@ -138,17 +136,12 @@ enum {
*
* %__GFP_ACCOUNT causes the allocation to be accounted to the active
* cgroup context.
- *
- * %__GFP_NO_OBJ_EXT causes slab allocation to have no object extension.
- * mark_obj_codetag_empty() should be called upon freeing for objects allocated
- * with this flag to indicate that their NULL tags are expected and normal.
*/
#define __GFP_RECLAIMABLE ((__force gfp_t)___GFP_RECLAIMABLE)
#define __GFP_WRITE ((__force gfp_t)___GFP_WRITE)
#define __GFP_HARDWALL ((__force gfp_t)___GFP_HARDWALL)
#define __GFP_THISNODE ((__force gfp_t)___GFP_THISNODE)
#define __GFP_ACCOUNT ((__force gfp_t)___GFP_ACCOUNT)
-#define __GFP_NO_OBJ_EXT ((__force gfp_t)___GFP_NO_OBJ_EXT)

/**
* DOC: Watermark modifiers
diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h
index a6e5a44c9b429..c1a05ff0feab0 100644
--- a/include/trace/events/mmflags.h
+++ b/include/trace/events/mmflags.h
@@ -54,18 +54,10 @@
# define TRACE_GFP_FLAGS_LOCKDEP
#endif

-#ifdef CONFIG_SLAB_OBJ_EXT
-# define TRACE_GFP_FLAGS_SLAB \
- TRACE_GFP_EM(NO_OBJ_EXT)
-#else
-# define TRACE_GFP_FLAGS_SLAB
-#endif
-
#define TRACE_GFP_FLAGS \
TRACE_GFP_FLAGS_GENERAL \
TRACE_GFP_FLAGS_KASAN \
- TRACE_GFP_FLAGS_LOCKDEP \
- TRACE_GFP_FLAGS_SLAB
+ TRACE_GFP_FLAGS_LOCKDEP

#undef TRACE_GFP_EM
#define TRACE_GFP_EM(a) TRACE_DEFINE_ENUM(___GFP_##a##_BIT);
diff --git a/tools/include/linux/gfp_types.h b/tools/include/linux/gfp_types.h
index 6c75df30a281d..a93b8bd200b76 100644
--- a/tools/include/linux/gfp_types.h
+++ b/tools/include/linux/gfp_types.h
@@ -55,7 +55,6 @@ enum {
#ifdef CONFIG_LOCKDEP
___GFP_NOLOCKDEP_BIT,
#endif
- ___GFP_NO_OBJ_EXT_BIT,
___GFP_LAST_BIT
};

@@ -96,7 +95,6 @@ enum {
#else
#define ___GFP_NOLOCKDEP 0
#endif
-#define ___GFP_NO_OBJ_EXT BIT(___GFP_NO_OBJ_EXT_BIT)

/*
* Physical address zone modifiers (see linux/mmzone.h - low four bits)
@@ -137,17 +135,12 @@ enum {
* node with no fallbacks or placement policy enforcements.
*
* %__GFP_ACCOUNT causes the allocation to be accounted to kmemcg.
- *
- * %__GFP_NO_OBJ_EXT causes slab allocation to have no object extension.
- * mark_obj_codetag_empty() should be called upon freeing for objects allocated
- * with this flag to indicate that their NULL tags are expected and normal.
*/
#define __GFP_RECLAIMABLE ((__force gfp_t)___GFP_RECLAIMABLE)
#define __GFP_WRITE ((__force gfp_t)___GFP_WRITE)
#define __GFP_HARDWALL ((__force gfp_t)___GFP_HARDWALL)
#define __GFP_THISNODE ((__force gfp_t)___GFP_THISNODE)
#define __GFP_ACCOUNT ((__force gfp_t)___GFP_ACCOUNT)
-#define __GFP_NO_OBJ_EXT ((__force gfp_t)___GFP_NO_OBJ_EXT)

/**
* DOC: Watermark modifiers

--
2.54.0