On 2/21/24 20:40, Suren Baghdasaryan wrote: > Currently slab pages can store only vectors of obj_cgroup pointers in > page->memcg_data. Introduce slabobj_ext structure to allow more data > to be stored for each slab object. Wrap obj_cgroup into slabobj_ext > to support current functionality while allowing to extend slabobj_ext > in the future. > > Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx> Hi, mostly good from slab perspective, just some fixups: > --- a/mm/slab.h > +++ b/mm/slab.h > -int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s, > - gfp_t gfp, bool new_slab); > -void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat, > - enum node_stat_item idx, int nr); > -#else /* CONFIG_MEMCG_KMEM */ > -static inline struct obj_cgroup **slab_objcgs(struct slab *slab) > +int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s, > + gfp_t gfp, bool new_slab); > We could remove this declaration and make the function static in mm/slub.c. > +#else /* CONFIG_SLAB_OBJ_EXT */ > + > +static inline struct slabobj_ext *slab_obj_exts(struct slab *slab) > { > return NULL; > } > > -static inline int memcg_alloc_slab_cgroups(struct slab *slab, > - struct kmem_cache *s, gfp_t gfp, > - bool new_slab) > +static inline int alloc_slab_obj_exts(struct slab *slab, > + struct kmem_cache *s, gfp_t gfp, > + bool new_slab) > { > return 0; > } Ditto > -#endif /* CONFIG_MEMCG_KMEM */ > + > +static inline struct slabobj_ext * > +prepare_slab_obj_exts_hook(struct kmem_cache *s, gfp_t flags, void *p) > +{ > + return NULL; > +} Same here (and the definition and usage even happens in later patch). > +#endif /* CONFIG_SLAB_OBJ_EXT */ > + > +#ifdef CONFIG_MEMCG_KMEM > +void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat, > + enum node_stat_item idx, int nr); > +#endif > > size_t __ksize(const void *objp); > > diff --git a/mm/slub.c b/mm/slub.c > index d31b03a8d9d5..76fb600fbc80 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -683,10 +683,10 @@ static inline bool __slab_update_freelist(struct kmem_cache *s, struct slab *sla > > if (s->flags & __CMPXCHG_DOUBLE) { > ret = __update_freelist_fast(slab, freelist_old, counters_old, > - freelist_new, counters_new); > + freelist_new, counters_new); > } else { > ret = __update_freelist_slow(slab, freelist_old, counters_old, > - freelist_new, counters_new); > + freelist_new, counters_new); > } > if (likely(ret)) > return true; > @@ -710,13 +710,13 @@ static inline bool slab_update_freelist(struct kmem_cache *s, struct slab *slab, > > if (s->flags & __CMPXCHG_DOUBLE) { > ret = __update_freelist_fast(slab, freelist_old, counters_old, > - freelist_new, counters_new); > + freelist_new, counters_new); > } else { > unsigned long flags; > > local_irq_save(flags); > ret = __update_freelist_slow(slab, freelist_old, counters_old, > - freelist_new, counters_new); > + freelist_new, counters_new); Please no drive-by fixups of whitespace in code you're not actually changing. I thought you agreed in v3? > static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s, > struct list_lru *lru, > struct obj_cgroup **objcgp, > @@ -2314,7 +2364,7 @@ static __always_inline void account_slab(struct slab *slab, int order, > struct kmem_cache *s, gfp_t gfp) > { > if (memcg_kmem_online() && (s->flags & SLAB_ACCOUNT)) > - memcg_alloc_slab_cgroups(slab, s, gfp, true); > + alloc_slab_obj_exts(slab, s, gfp, true); This is still guarded by the memcg_kmem_online() static key, which is good. > > mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s), > PAGE_SIZE << order); > @@ -2323,8 +2373,7 @@ static __always_inline void account_slab(struct slab *slab, int order, > static __always_inline void unaccount_slab(struct slab *slab, int order, > struct kmem_cache *s) > { > - if (memcg_kmem_online()) > - memcg_free_slab_cgroups(slab); > + free_slab_obj_exts(slab); But this no longer is, yet it still could be? > > mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s), > -(PAGE_SIZE << order));