On 3/15/24 16:43, Suren Baghdasaryan wrote:
> On Fri, Mar 15, 2024 at 3:58 AM Vlastimil Babka <vbabka@xxxxxxx> wrote:
>>
>> On 3/6/24 19:24, Suren Baghdasaryan wrote:
>> > Account slab allocations using codetag reference embedded into slabobj_ext.
>> >
>> > 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: Kees Cook <keescook@xxxxxxxxxxxx>
>>
>> Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx>
>>
>> Nit below:
>>
>> > @@ -3833,6 +3913,7 @@ void slab_post_alloc_hook(struct kmem_cache *s, struct obj_cgroup *objcg,
>> > unsigned int orig_size)
>> > {
>> > unsigned int zero_size = s->object_size;
>> > + struct slabobj_ext *obj_exts;
>> > bool kasan_init = init;
>> > size_t i;
>> > gfp_t init_flags = flags & gfp_allowed_mask;
>> > @@ -3875,6 +3956,12 @@ void slab_post_alloc_hook(struct kmem_cache *s, struct obj_cgroup *objcg,
>> > kmemleak_alloc_recursive(p[i], s->object_size, 1,
>> > s->flags, init_flags);
>> > kmsan_slab_alloc(s, p[i], init_flags);
>> > + obj_exts = prepare_slab_obj_exts_hook(s, flags, p[i]);
>> > +#ifdef CONFIG_MEM_ALLOC_PROFILING
>> > + /* obj_exts can be allocated for other reasons */
>> > + if (likely(obj_exts) && mem_alloc_profiling_enabled())
Could you at least flip these two checks then so the static key one goes first?
>> > + alloc_tag_add(&obj_exts->ref, current->alloc_tag, s->size);
>> > +#endif
>>
>> I think you could still do this a bit better:
>>
>> Check mem_alloc_profiling_enabled() once before the whole block calling
>> prepare_slab_obj_exts_hook() and alloc_tag_add()
>> Remove need_slab_obj_ext() check from prepare_slab_obj_exts_hook()
>
> Agree about checking mem_alloc_profiling_enabled() early and one time,
> except I would like to use need_slab_obj_ext() instead of
> mem_alloc_profiling_enabled() for that check. Currently they are
> equivalent but if there are more slab_obj_ext users in the future then
> there will be cases when we need to prepare_slab_obj_exts_hook() even
> when mem_alloc_profiling_enabled()==false. need_slab_obj_ext() will be
> easy to extend for such cases.
I thought we don't generally future-proof internal implementation details
like this until it's actually needed. But at least what I suggested above
would help, thanks.
> Thanks,
> Suren.
>
>>
>> > }
>> >
>> > memcg_slab_post_alloc_hook(s, objcg, flags, size, p);
>> > @@ -4353,6 +4440,7 @@ void slab_free(struct kmem_cache *s, struct slab *slab, void *object,
>> > unsigned long addr)
>> > {
>> > memcg_slab_free_hook(s, slab, &object, 1);
>> > + alloc_tagging_slab_free_hook(s, slab, &object, 1);
>> >
>> > if (likely(slab_free_hook(s, object, slab_want_init_on_free(s))))
>> > do_slab_free(s, slab, object, object, 1, addr);
>> > @@ -4363,6 +4451,7 @@ void slab_free_bulk(struct kmem_cache *s, struct slab *slab, void *head,
>> > void *tail, void **p, int cnt, unsigned long addr)
>> > {
>> > memcg_slab_free_hook(s, slab, p, cnt);
>> > + alloc_tagging_slab_free_hook(s, slab, p, cnt);
>> > /*
>> > * With KASAN enabled slab_free_freelist_hook modifies the freelist
>> > * to remove objects, whose reuse must be delayed.
>>
