[PATCH v2 22/39] lib: add codetag reference into slabobj_ext

[Suren Baghdasaryan]

To store code tag for every slab object, a codetag reference is embedded
into slabobj_ext when CONFIG_MEM_ALLOC_PROFILING=y.

Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Co-developed-by: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Signed-off-by: Kent Overstreet <kent.overstreet@xxxxxxxxx>
---
 include/linux/memcontrol.h | 5 +++++
 lib/Kconfig.debug          | 1 +
 mm/slab.h                  | 4 ++++
 3 files changed, 10 insertions(+)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index f3ede28b6fa6..853a24b5f713 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1613,7 +1613,12 @@ unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
  * if MEMCG_DATA_OBJEXTS is set.
  */
 struct slabobj_ext {
+#ifdef CONFIG_MEMCG_KMEM
 	struct obj_cgroup *objcg;
+#endif
+#ifdef CONFIG_MEM_ALLOC_PROFILING
+	union codetag_ref ref;
+#endif
 } __aligned(8);
 
 static inline void __inc_lruvec_kmem_state(void *p, enum node_stat_item idx)
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index e1eda1450d68..482a6aae7664 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -973,6 +973,7 @@ config MEM_ALLOC_PROFILING
 	depends on !DEBUG_FORCE_WEAK_PER_CPU
 	select CODE_TAGGING
 	select PAGE_EXTENSION
+	select SLAB_OBJ_EXT
 	help
 	  Track allocation source code and record total allocation size
 	  initiated at that code location. The mechanism can be used to track
diff --git a/mm/slab.h b/mm/slab.h
index 60417fd262ea..293210ed10a9 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -457,6 +457,10 @@ int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s,
 
 static inline bool need_slab_obj_ext(void)
 {
+#ifdef CONFIG_MEM_ALLOC_PROFILING
+	if (mem_alloc_profiling_enabled())
+		return true;
+#endif
 	/*
 	 * CONFIG_MEMCG_KMEM creates vector of obj_cgroup objects conditionally
 	 * inside memcg_slab_post_alloc_hook. No other users for now.
-- 
2.42.0.758.gaed0368e0e-goog