[PATCH RFC 15/15] mm: remove the __GFP_NO_OBJ_EXT flag

["Vlastimil Babka (SUSE)" <vbabka@kernel.org>]

All users of the flag are converted to SLAB_ALLOC_NO_RECURSE. Free up
the flag bit.

Signed-off-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
---
 include/linux/gfp_types.h       |  7 -------
 include/linux/slab.h            |  2 +-
 include/trace/events/mmflags.h  | 10 +---------
 lib/alloc_tag.c                 |  2 +-
 tools/include/linux/gfp_types.h |  7 -------
 5 files changed, 3 insertions(+), 25 deletions(-)

diff --git a/include/linux/gfp_types.h b/include/linux/gfp_types.h
index 6c75df30a281..a93b8bd200b7 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)
@@ -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
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 11e82fdbe8d3..15d1917b81d3 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -1043,7 +1043,7 @@ void *_kmalloc_nolock_noprof(DECL_TOKEN_PARAMS(size, token), gfp_t gfp_flags, in
 /**
  * kmalloc_nolock - Allocate an object of given size from any context.
  * @size: size to allocate
- * @gfp_flags: GFP flags. Only __GFP_ACCOUNT, __GFP_ZERO, __GFP_NO_OBJ_EXT
+ * @gfp_flags: GFP flags. Only __GFP_ACCOUNT, __GFP_ZERO
  * allowed.
  * @node: node number of the target node.
  *
diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h
index a6e5a44c9b42..c1a05ff0feab 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/lib/alloc_tag.c b/lib/alloc_tag.c
index ed1bdcf1f8ab..63686b44a23d 100644
--- a/lib/alloc_tag.c
+++ b/lib/alloc_tag.c
@@ -776,7 +776,7 @@ static __init bool need_page_alloc_tagging(void)
  * If insufficient, a warning will be triggered to alert the user.
  *
  * TODO: Replace fixed-size array with dynamic allocation using
- * a GFP flag similar to ___GFP_NO_OBJ_EXT to avoid recursion.
+ * something similar to slab's SLAB_ALLOC_NO_RECURSE to avoid recursion.
  */
 #define EARLY_ALLOC_PFN_MAX		8192
 
diff --git a/tools/include/linux/gfp_types.h b/tools/include/linux/gfp_types.h
index 6c75df30a281..a93b8bd200b7 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