Re: [PATCH v4 21/36] lib: add codetag reference into slabobj_ext

[Vlastimil Babka]

On 2/21/24 20:40, Suren Baghdasaryan wrote:
> 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>

Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx>

> ---
>  include/linux/memcontrol.h | 5 +++++
>  lib/Kconfig.debug          | 1 +
>  2 files changed, 6 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