[PATCH v2 08/39] mm: introduce __GFP_NO_OBJ_EXT flag to selectively prevent slabobj_ext creation

From: Suren Baghdasaryan
Date: Tue Oct 24 2023 - 09:47:48 EST


Introduce __GFP_NO_OBJ_EXT flag in order to prevent recursive allocations
when allocating slabobj_ext on a slab.

Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
---
include/linux/gfp_types.h | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/include/linux/gfp_types.h b/include/linux/gfp_types.h
index 3fbe624763d9..1c6573d69347 100644
--- a/include/linux/gfp_types.h
+++ b/include/linux/gfp_types.h
@@ -52,6 +52,9 @@ enum {
#endif
#ifdef CONFIG_LOCKDEP
___GFP_NOLOCKDEP_BIT,
+#endif
+#ifdef CONFIG_SLAB_OBJ_EXT
+ ___GFP_NO_OBJ_EXT_BIT,
#endif
___GFP_LAST_BIT
};
@@ -93,6 +96,11 @@ enum {
#else
#define ___GFP_NOLOCKDEP 0
#endif
+#ifdef CONFIG_SLAB_OBJ_EXT
+#define ___GFP_NO_OBJ_EXT BIT(___GFP_NO_OBJ_EXT_BIT)
+#else
+#define ___GFP_NO_OBJ_EXT 0
+#endif

/*
* Physical address zone modifiers (see linux/mmzone.h - low four bits)
@@ -133,12 +141,15 @@ 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.
*/
#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
--
2.42.0.758.gaed0368e0e-goog