[PATCH v3 20/35] lib: add codetag reference into slabobj_ext

Suren Baghdasaryan
2024-02-12T21:40:17Z

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@google.com>
Co-developed-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
---
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 f3584e98b640..2b010316016c 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1653,7 +1653,12 @@ 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 7bbdb0ddb011..9ecfcdb54417 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -979,6 +979,7 @@ 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 77cf7474fe46..224a4b2305fb 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -569,6 +569,10 @@ 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.
--
2.43.0.687.g38aa6559b0-goog