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Date: Mon, 12 Feb 2024 13:38:52 -0800
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Subject: [PATCH v3 06/35] mm: introduce __GFP_NO_OBJ_EXT flag to selectively
 prevent slabobj_ext creation
From: Suren Baghdasaryan <surenb@google.com>
To: akpm@linux-foundation.org
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Content-Type: text/plain; charset="UTF-8"

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@google.com>
---
 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 868c8fb1bbc1..e36e168d8cfd 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
-- 
2.43.0.687.g38aa6559b0-goog