On Mon, Feb 26, 2024 at 8:26 AM Vlastimil Babka <vbabka@xxxxxxx> wrote: > > 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. Ack. > > > +#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 Ack. > > > -#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). Ack. > > > +#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? Sorry, I must have misunderstood your previous comment. I thought you were saying that the alignment I changed to was incorrect. I'll keep them untouched. > > > 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? Yes, I missed that, it seems. free_slab_obj_exts() would bail out but still checking the static key is more efficient. I'll revive this check. Thanks for the review! Suren. > > > > > mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s), > > -(PAGE_SIZE << order)); >