| Message ID | 20220830214919.53220-12-surenb@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Code tagging framework and applications | expand |
On Tue, Aug 30, 2022 at 02:49:00PM -0700, 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. Wraps obj_cgroup into slabobj_ext > to support current functionality while allowing to extend slabobj_ext > in the future. > > Note: ideally the config dependency should be turned the other way around: > MEMCG should depend on SLAB_OBJ_EXT and {page|slab|folio}.memcg_data would > be renamed to something like {page|slab|folio}.objext_data. However doing > this in RFC would introduce considerable churn unrelated to the overall > idea, so avoiding this until v1. Hi Suren! I'd say CONFIG_MEMCG_KMEM and CONFIG_YOUR_NEW_STUFF should both depend on SLAB_OBJ_EXT. CONFIG_MEMCG_KMEM depend on CONFIG_MEMCG anyway. > > Signed-off-by: Suren Baghdasaryan <surenb@google.com> > --- > include/linux/memcontrol.h | 18 ++++-- > init/Kconfig | 5 ++ > mm/kfence/core.c | 2 +- > mm/memcontrol.c | 60 ++++++++++--------- > mm/page_owner.c | 2 +- > mm/slab.h | 119 +++++++++++++++++++++++++------------ > 6 files changed, 131 insertions(+), 75 deletions(-) > > diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h > index 6257867fbf95..315399f77173 100644 > --- a/include/linux/memcontrol.h > +++ b/include/linux/memcontrol.h > @@ -227,6 +227,14 @@ struct obj_cgroup { > }; > }; > > +/* > + * Extended information for slab objects stored as an array in page->memcg_data > + * if MEMCG_DATA_OBJEXTS is set. > + */ > +struct slabobj_ext { > + struct obj_cgroup *objcg; > +} __aligned(8); Why do we need this aligment requirement? > + > /* > * The memory controller data structure. The memory controller controls both > * page cache and RSS per cgroup. We would eventually like to provide > @@ -363,7 +371,7 @@ extern struct mem_cgroup *root_mem_cgroup; > > enum page_memcg_data_flags { > /* page->memcg_data is a pointer to an objcgs vector */ > - MEMCG_DATA_OBJCGS = (1UL << 0), > + MEMCG_DATA_OBJEXTS = (1UL << 0), > /* page has been accounted as a non-slab kernel page */ > MEMCG_DATA_KMEM = (1UL << 1), > /* the next bit after the last actual flag */ > @@ -401,7 +409,7 @@ static inline struct mem_cgroup *__folio_memcg(struct folio *folio) > unsigned long memcg_data = folio->memcg_data; > > VM_BUG_ON_FOLIO(folio_test_slab(folio), folio); > - VM_BUG_ON_FOLIO(memcg_data & MEMCG_DATA_OBJCGS, folio); > + VM_BUG_ON_FOLIO(memcg_data & MEMCG_DATA_OBJEXTS, folio); > VM_BUG_ON_FOLIO(memcg_data & MEMCG_DATA_KMEM, folio); > > return (struct mem_cgroup *)(memcg_data & ~MEMCG_DATA_FLAGS_MASK); > @@ -422,7 +430,7 @@ static inline struct obj_cgroup *__folio_objcg(struct folio *folio) > unsigned long memcg_data = folio->memcg_data; > > VM_BUG_ON_FOLIO(folio_test_slab(folio), folio); > - VM_BUG_ON_FOLIO(memcg_data & MEMCG_DATA_OBJCGS, folio); > + VM_BUG_ON_FOLIO(memcg_data & MEMCG_DATA_OBJEXTS, folio); > VM_BUG_ON_FOLIO(!(memcg_data & MEMCG_DATA_KMEM), folio); > > return (struct obj_cgroup *)(memcg_data & ~MEMCG_DATA_FLAGS_MASK); > @@ -517,7 +525,7 @@ static inline struct mem_cgroup *page_memcg_check(struct page *page) > */ > unsigned long memcg_data = READ_ONCE(page->memcg_data); > > - if (memcg_data & MEMCG_DATA_OBJCGS) > + if (memcg_data & MEMCG_DATA_OBJEXTS) > return NULL; > > if (memcg_data & MEMCG_DATA_KMEM) { > @@ -556,7 +564,7 @@ static inline struct mem_cgroup *get_mem_cgroup_from_objcg(struct obj_cgroup *ob > static inline bool folio_memcg_kmem(struct folio *folio) > { > VM_BUG_ON_PGFLAGS(PageTail(&folio->page), &folio->page); > - VM_BUG_ON_FOLIO(folio->memcg_data & MEMCG_DATA_OBJCGS, folio); > + VM_BUG_ON_FOLIO(folio->memcg_data & MEMCG_DATA_OBJEXTS, folio); > return folio->memcg_data & MEMCG_DATA_KMEM; > } > > diff --git a/init/Kconfig b/init/Kconfig > index 532362fcfe31..82396d7a2717 100644 > --- a/init/Kconfig > +++ b/init/Kconfig > @@ -958,6 +958,10 @@ config MEMCG > help > Provides control over the memory footprint of tasks in a cgroup. > > +config SLAB_OBJ_EXT > + bool > + depends on MEMCG > + > config MEMCG_SWAP > bool > depends on MEMCG && SWAP > @@ -966,6 +970,7 @@ config MEMCG_SWAP > config MEMCG_KMEM > bool > depends on MEMCG && !SLOB > + select SLAB_OBJ_EXT > default y > > config BLK_CGROUP > diff --git a/mm/kfence/core.c b/mm/kfence/core.c > index c252081b11df..c0958e4a32e2 100644 > --- a/mm/kfence/core.c > +++ b/mm/kfence/core.c > @@ -569,7 +569,7 @@ static unsigned long kfence_init_pool(void) > __folio_set_slab(slab_folio(slab)); > #ifdef CONFIG_MEMCG > slab->memcg_data = (unsigned long)&kfence_metadata[i / 2 - 1].objcg | > - MEMCG_DATA_OBJCGS; > + MEMCG_DATA_OBJEXTS; > #endif > } > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index b69979c9ced5..3f407ef2f3f1 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -2793,7 +2793,7 @@ static void commit_charge(struct folio *folio, struct mem_cgroup *memcg) > folio->memcg_data = (unsigned long)memcg; > } > > -#ifdef CONFIG_MEMCG_KMEM > +#ifdef CONFIG_SLAB_OBJ_EXT > /* > * The allocated objcg pointers array is not accounted directly. > * Moreover, it should not come from DMA buffer and is not readily > @@ -2801,38 +2801,20 @@ static void commit_charge(struct folio *folio, struct mem_cgroup *memcg) > */ > #define OBJCGS_CLEAR_MASK (__GFP_DMA | __GFP_RECLAIMABLE | __GFP_ACCOUNT) > > -/* > - * mod_objcg_mlstate() may be called with irq enabled, so > - * mod_memcg_lruvec_state() should be used. > - */ > -static inline void mod_objcg_mlstate(struct obj_cgroup *objcg, > - struct pglist_data *pgdat, > - enum node_stat_item idx, int nr) > -{ > - struct mem_cgroup *memcg; > - struct lruvec *lruvec; > - > - rcu_read_lock(); > - memcg = obj_cgroup_memcg(objcg); > - lruvec = mem_cgroup_lruvec(memcg, pgdat); > - mod_memcg_lruvec_state(lruvec, idx, nr); > - rcu_read_unlock(); > -} > - > -int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s, > - gfp_t gfp, bool new_slab) > +int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s, > + gfp_t gfp, bool new_slab) > { > unsigned int objects = objs_per_slab(s, slab); > unsigned long memcg_data; > void *vec; > > gfp &= ~OBJCGS_CLEAR_MASK; > - vec = kcalloc_node(objects, sizeof(struct obj_cgroup *), gfp, > + vec = kcalloc_node(objects, sizeof(struct slabobj_ext), gfp, > slab_nid(slab)); > if (!vec) > return -ENOMEM; > > - memcg_data = (unsigned long) vec | MEMCG_DATA_OBJCGS; > + memcg_data = (unsigned long) vec | MEMCG_DATA_OBJEXTS; > if (new_slab) { > /* > * If the slab is brand new and nobody can yet access its > @@ -2843,7 +2825,7 @@ int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s, > } else if (cmpxchg(&slab->memcg_data, 0, memcg_data)) { > /* > * If the slab is already in use, somebody can allocate and > - * assign obj_cgroups in parallel. In this case the existing > + * assign slabobj_exts in parallel. In this case the existing > * objcg vector should be reused. > */ > kfree(vec); > @@ -2853,6 +2835,26 @@ int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s, > kmemleak_not_leak(vec); > return 0; > } > +#endif /* CONFIG_SLAB_OBJ_EXT */ > + > +#ifdef CONFIG_MEMCG_KMEM > +/* > + * mod_objcg_mlstate() may be called with irq enabled, so > + * mod_memcg_lruvec_state() should be used. > + */ > +static inline void mod_objcg_mlstate(struct obj_cgroup *objcg, > + struct pglist_data *pgdat, > + enum node_stat_item idx, int nr) > +{ > + struct mem_cgroup *memcg; > + struct lruvec *lruvec; > + > + rcu_read_lock(); > + memcg = obj_cgroup_memcg(objcg); > + lruvec = mem_cgroup_lruvec(memcg, pgdat); > + mod_memcg_lruvec_state(lruvec, idx, nr); > + rcu_read_unlock(); > +} > > static __always_inline > struct mem_cgroup *mem_cgroup_from_obj_folio(struct folio *folio, void *p) > @@ -2863,18 +2865,18 @@ struct mem_cgroup *mem_cgroup_from_obj_folio(struct folio *folio, void *p) > * slab->memcg_data. > */ > if (folio_test_slab(folio)) { > - struct obj_cgroup **objcgs; > + struct slabobj_ext *obj_exts; > struct slab *slab; > unsigned int off; > > slab = folio_slab(folio); > - objcgs = slab_objcgs(slab); > - if (!objcgs) > + obj_exts = slab_obj_exts(slab); > + if (!obj_exts) > return NULL; > > off = obj_to_index(slab->slab_cache, slab, p); > - if (objcgs[off]) > - return obj_cgroup_memcg(objcgs[off]); > + if (obj_exts[off].objcg) > + return obj_cgroup_memcg(obj_exts[off].objcg); > > return NULL; > } > diff --git a/mm/page_owner.c b/mm/page_owner.c > index e4c6f3f1695b..fd4af1ad34b8 100644 > --- a/mm/page_owner.c > +++ b/mm/page_owner.c > @@ -353,7 +353,7 @@ static inline int print_page_owner_memcg(char *kbuf, size_t count, int ret, > if (!memcg_data) > goto out_unlock; > > - if (memcg_data & MEMCG_DATA_OBJCGS) > + if (memcg_data & MEMCG_DATA_OBJEXTS) > ret += scnprintf(kbuf + ret, count - ret, > "Slab cache page\n"); > > diff --git a/mm/slab.h b/mm/slab.h > index 4ec82bec15ec..c767ce3f0fe2 100644 > --- a/mm/slab.h > +++ b/mm/slab.h > @@ -422,36 +422,94 @@ static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t fla > return false; > } > > +#ifdef CONFIG_SLAB_OBJ_EXT > + > +static inline bool is_kmem_only_obj_ext(void) > +{ > #ifdef CONFIG_MEMCG_KMEM > + return sizeof(struct slabobj_ext) == sizeof(struct obj_cgroup *); > +#else > + return false; > +#endif > +} > + > /* > - * slab_objcgs - get the object cgroups vector associated with a slab > + * slab_obj_exts - get the pointer to the slab object extension vector > + * associated with a slab. > * @slab: a pointer to the slab struct > * > - * Returns a pointer to the object cgroups vector associated with the slab, > + * Returns a pointer to the object extension vector associated with the slab, > * or NULL if no such vector has been associated yet. > */ > -static inline struct obj_cgroup **slab_objcgs(struct slab *slab) > +static inline struct slabobj_ext *slab_obj_exts(struct slab *slab) > { > unsigned long memcg_data = READ_ONCE(slab->memcg_data); > > - VM_BUG_ON_PAGE(memcg_data && !(memcg_data & MEMCG_DATA_OBJCGS), > + VM_BUG_ON_PAGE(memcg_data && !(memcg_data & MEMCG_DATA_OBJEXTS), > slab_page(slab)); > VM_BUG_ON_PAGE(memcg_data & MEMCG_DATA_KMEM, slab_page(slab)); > > - return (struct obj_cgroup **)(memcg_data & ~MEMCG_DATA_FLAGS_MASK); > + return (struct slabobj_ext *)(memcg_data & ~MEMCG_DATA_FLAGS_MASK); > } > > -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); > +int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s, > + gfp_t gfp, bool new_slab); > > -static inline void memcg_free_slab_cgroups(struct slab *slab) > +static inline void free_slab_obj_exts(struct slab *slab) > { > - kfree(slab_objcgs(slab)); > + struct slabobj_ext *obj_exts; > + > + if (!memcg_kmem_enabled() && is_kmem_only_obj_ext()) > + return; Hm, not sure I understand this. I kmem is disabled and is_kmem_only_obj_ext() is true, shouldn't slab->memcg_data == NULL (always)? > + > + obj_exts = slab_obj_exts(slab); > + kfree(obj_exts); > slab->memcg_data = 0; > } > > +static inline void prepare_slab_obj_exts_hook(struct kmem_cache *s, gfp_t flags, void *p) > +{ > + struct slab *slab; > + > + /* If kmem is the only extension then the vector will be created conditionally */ > + if (is_kmem_only_obj_ext()) > + return; > + > + slab = virt_to_slab(p); > + if (!slab_obj_exts(slab)) > + WARN(alloc_slab_obj_exts(slab, s, flags, false), > + "%s, %s: Failed to create slab extension vector!\n", > + __func__, s->name); > +} This looks a bit crypric: the action is wrapped into WARN() and the rest is a set of (semi-)static checks. Can we, please, invert it? E.g. something like: if (slab_alloc_tracking_enabled()) { slab = virt_to_slab(p); if (!slab_obj_exts(slab)) WARN(alloc_slab_obj_exts(slab, s, flags, false), "%s, %s: Failed to create slab extension vector!\n", __func__, s->name); } The rest looks good to me. Thank you!
On Thu, Sep 1, 2022 at 4:36 PM Roman Gushchin <roman.gushchin@linux.dev> wrote: > > On Tue, Aug 30, 2022 at 02:49:00PM -0700, 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. Wraps obj_cgroup into slabobj_ext > > to support current functionality while allowing to extend slabobj_ext > > in the future. > > > > Note: ideally the config dependency should be turned the other way around: > > MEMCG should depend on SLAB_OBJ_EXT and {page|slab|folio}.memcg_data would > > be renamed to something like {page|slab|folio}.objext_data. However doing > > this in RFC would introduce considerable churn unrelated to the overall > > idea, so avoiding this until v1. > > Hi Suren! Hi Roman, > > I'd say CONFIG_MEMCG_KMEM and CONFIG_YOUR_NEW_STUFF should both depend on > SLAB_OBJ_EXT. > CONFIG_MEMCG_KMEM depend on CONFIG_MEMCG anyway. Yes, I agree. I wanted to mention here that the current dependency is incorrect and should be reworked. Having both depending on SLAB_OBJ_EXT seems like the right approach. > > > > > Signed-off-by: Suren Baghdasaryan <surenb@google.com> > > --- > > include/linux/memcontrol.h | 18 ++++-- > > init/Kconfig | 5 ++ > > mm/kfence/core.c | 2 +- > > mm/memcontrol.c | 60 ++++++++++--------- > > mm/page_owner.c | 2 +- > > mm/slab.h | 119 +++++++++++++++++++++++++------------ > > 6 files changed, 131 insertions(+), 75 deletions(-) > > > > diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h > > index 6257867fbf95..315399f77173 100644 > > --- a/include/linux/memcontrol.h > > +++ b/include/linux/memcontrol.h > > @@ -227,6 +227,14 @@ struct obj_cgroup { > > }; > > }; > > > > +/* > > + * Extended information for slab objects stored as an array in page->memcg_data > > + * if MEMCG_DATA_OBJEXTS is set. > > + */ > > +struct slabobj_ext { > > + struct obj_cgroup *objcg; > > +} __aligned(8); > > Why do we need this aligment requirement? To save space by avoiding padding, however, all members today will be pointers, so it's meaningless and we can safely drop it. > > > + > > /* > > * The memory controller data structure. The memory controller controls both > > * page cache and RSS per cgroup. We would eventually like to provide > > @@ -363,7 +371,7 @@ extern struct mem_cgroup *root_mem_cgroup; > > > > enum page_memcg_data_flags { > > /* page->memcg_data is a pointer to an objcgs vector */ > > - MEMCG_DATA_OBJCGS = (1UL << 0), > > + MEMCG_DATA_OBJEXTS = (1UL << 0), > > /* page has been accounted as a non-slab kernel page */ > > MEMCG_DATA_KMEM = (1UL << 1), > > /* the next bit after the last actual flag */ > > @@ -401,7 +409,7 @@ static inline struct mem_cgroup *__folio_memcg(struct folio *folio) > > unsigned long memcg_data = folio->memcg_data; > > > > VM_BUG_ON_FOLIO(folio_test_slab(folio), folio); > > - VM_BUG_ON_FOLIO(memcg_data & MEMCG_DATA_OBJCGS, folio); > > + VM_BUG_ON_FOLIO(memcg_data & MEMCG_DATA_OBJEXTS, folio); > > VM_BUG_ON_FOLIO(memcg_data & MEMCG_DATA_KMEM, folio); > > > > return (struct mem_cgroup *)(memcg_data & ~MEMCG_DATA_FLAGS_MASK); > > @@ -422,7 +430,7 @@ static inline struct obj_cgroup *__folio_objcg(struct folio *folio) > > unsigned long memcg_data = folio->memcg_data; > > > > VM_BUG_ON_FOLIO(folio_test_slab(folio), folio); > > - VM_BUG_ON_FOLIO(memcg_data & MEMCG_DATA_OBJCGS, folio); > > + VM_BUG_ON_FOLIO(memcg_data & MEMCG_DATA_OBJEXTS, folio); > > VM_BUG_ON_FOLIO(!(memcg_data & MEMCG_DATA_KMEM), folio); > > > > return (struct obj_cgroup *)(memcg_data & ~MEMCG_DATA_FLAGS_MASK); > > @@ -517,7 +525,7 @@ static inline struct mem_cgroup *page_memcg_check(struct page *page) > > */ > > unsigned long memcg_data = READ_ONCE(page->memcg_data); > > > > - if (memcg_data & MEMCG_DATA_OBJCGS) > > + if (memcg_data & MEMCG_DATA_OBJEXTS) > > return NULL; > > > > if (memcg_data & MEMCG_DATA_KMEM) { > > @@ -556,7 +564,7 @@ static inline struct mem_cgroup *get_mem_cgroup_from_objcg(struct obj_cgroup *ob > > static inline bool folio_memcg_kmem(struct folio *folio) > > { > > VM_BUG_ON_PGFLAGS(PageTail(&folio->page), &folio->page); > > - VM_BUG_ON_FOLIO(folio->memcg_data & MEMCG_DATA_OBJCGS, folio); > > + VM_BUG_ON_FOLIO(folio->memcg_data & MEMCG_DATA_OBJEXTS, folio); > > return folio->memcg_data & MEMCG_DATA_KMEM; > > } > > > > diff --git a/init/Kconfig b/init/Kconfig > > index 532362fcfe31..82396d7a2717 100644 > > --- a/init/Kconfig > > +++ b/init/Kconfig > > @@ -958,6 +958,10 @@ config MEMCG > > help > > Provides control over the memory footprint of tasks in a cgroup. > > > > +config SLAB_OBJ_EXT > > + bool > > + depends on MEMCG > > + > > config MEMCG_SWAP > > bool > > depends on MEMCG && SWAP > > @@ -966,6 +970,7 @@ config MEMCG_SWAP > > config MEMCG_KMEM > > bool > > depends on MEMCG && !SLOB > > + select SLAB_OBJ_EXT > > default y > > > > config BLK_CGROUP > > diff --git a/mm/kfence/core.c b/mm/kfence/core.c > > index c252081b11df..c0958e4a32e2 100644 > > --- a/mm/kfence/core.c > > +++ b/mm/kfence/core.c > > @@ -569,7 +569,7 @@ static unsigned long kfence_init_pool(void) > > __folio_set_slab(slab_folio(slab)); > > #ifdef CONFIG_MEMCG > > slab->memcg_data = (unsigned long)&kfence_metadata[i / 2 - 1].objcg | > > - MEMCG_DATA_OBJCGS; > > + MEMCG_DATA_OBJEXTS; > > #endif > > } > > > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > > index b69979c9ced5..3f407ef2f3f1 100644 > > --- a/mm/memcontrol.c > > +++ b/mm/memcontrol.c > > @@ -2793,7 +2793,7 @@ static void commit_charge(struct folio *folio, struct mem_cgroup *memcg) > > folio->memcg_data = (unsigned long)memcg; > > } > > > > -#ifdef CONFIG_MEMCG_KMEM > > +#ifdef CONFIG_SLAB_OBJ_EXT > > /* > > * The allocated objcg pointers array is not accounted directly. > > * Moreover, it should not come from DMA buffer and is not readily > > @@ -2801,38 +2801,20 @@ static void commit_charge(struct folio *folio, struct mem_cgroup *memcg) > > */ > > #define OBJCGS_CLEAR_MASK (__GFP_DMA | __GFP_RECLAIMABLE | __GFP_ACCOUNT) > > > > -/* > > - * mod_objcg_mlstate() may be called with irq enabled, so > > - * mod_memcg_lruvec_state() should be used. > > - */ > > -static inline void mod_objcg_mlstate(struct obj_cgroup *objcg, > > - struct pglist_data *pgdat, > > - enum node_stat_item idx, int nr) > > -{ > > - struct mem_cgroup *memcg; > > - struct lruvec *lruvec; > > - > > - rcu_read_lock(); > > - memcg = obj_cgroup_memcg(objcg); > > - lruvec = mem_cgroup_lruvec(memcg, pgdat); > > - mod_memcg_lruvec_state(lruvec, idx, nr); > > - rcu_read_unlock(); > > -} > > - > > -int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s, > > - gfp_t gfp, bool new_slab) > > +int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s, > > + gfp_t gfp, bool new_slab) > > { > > unsigned int objects = objs_per_slab(s, slab); > > unsigned long memcg_data; > > void *vec; > > > > gfp &= ~OBJCGS_CLEAR_MASK; > > - vec = kcalloc_node(objects, sizeof(struct obj_cgroup *), gfp, > > + vec = kcalloc_node(objects, sizeof(struct slabobj_ext), gfp, > > slab_nid(slab)); > > if (!vec) > > return -ENOMEM; > > > > - memcg_data = (unsigned long) vec | MEMCG_DATA_OBJCGS; > > + memcg_data = (unsigned long) vec | MEMCG_DATA_OBJEXTS; > > if (new_slab) { > > /* > > * If the slab is brand new and nobody can yet access its > > @@ -2843,7 +2825,7 @@ int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s, > > } else if (cmpxchg(&slab->memcg_data, 0, memcg_data)) { > > /* > > * If the slab is already in use, somebody can allocate and > > - * assign obj_cgroups in parallel. In this case the existing > > + * assign slabobj_exts in parallel. In this case the existing > > * objcg vector should be reused. > > */ > > kfree(vec); > > @@ -2853,6 +2835,26 @@ int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s, > > kmemleak_not_leak(vec); > > return 0; > > } > > +#endif /* CONFIG_SLAB_OBJ_EXT */ > > + > > +#ifdef CONFIG_MEMCG_KMEM > > +/* > > + * mod_objcg_mlstate() may be called with irq enabled, so > > + * mod_memcg_lruvec_state() should be used. > > + */ > > +static inline void mod_objcg_mlstate(struct obj_cgroup *objcg, > > + struct pglist_data *pgdat, > > + enum node_stat_item idx, int nr) > > +{ > > + struct mem_cgroup *memcg; > > + struct lruvec *lruvec; > > + > > + rcu_read_lock(); > > + memcg = obj_cgroup_memcg(objcg); > > + lruvec = mem_cgroup_lruvec(memcg, pgdat); > > + mod_memcg_lruvec_state(lruvec, idx, nr); > > + rcu_read_unlock(); > > +} > > > > static __always_inline > > struct mem_cgroup *mem_cgroup_from_obj_folio(struct folio *folio, void *p) > > @@ -2863,18 +2865,18 @@ struct mem_cgroup *mem_cgroup_from_obj_folio(struct folio *folio, void *p) > > * slab->memcg_data. > > */ > > if (folio_test_slab(folio)) { > > - struct obj_cgroup **objcgs; > > + struct slabobj_ext *obj_exts; > > struct slab *slab; > > unsigned int off; > > > > slab = folio_slab(folio); > > - objcgs = slab_objcgs(slab); > > - if (!objcgs) > > + obj_exts = slab_obj_exts(slab); > > + if (!obj_exts) > > return NULL; > > > > off = obj_to_index(slab->slab_cache, slab, p); > > - if (objcgs[off]) > > - return obj_cgroup_memcg(objcgs[off]); > > + if (obj_exts[off].objcg) > > + return obj_cgroup_memcg(obj_exts[off].objcg); > > > > return NULL; > > } > > diff --git a/mm/page_owner.c b/mm/page_owner.c > > index e4c6f3f1695b..fd4af1ad34b8 100644 > > --- a/mm/page_owner.c > > +++ b/mm/page_owner.c > > @@ -353,7 +353,7 @@ static inline int print_page_owner_memcg(char *kbuf, size_t count, int ret, > > if (!memcg_data) > > goto out_unlock; > > > > - if (memcg_data & MEMCG_DATA_OBJCGS) > > + if (memcg_data & MEMCG_DATA_OBJEXTS) > > ret += scnprintf(kbuf + ret, count - ret, > > "Slab cache page\n"); > > > > diff --git a/mm/slab.h b/mm/slab.h > > index 4ec82bec15ec..c767ce3f0fe2 100644 > > --- a/mm/slab.h > > +++ b/mm/slab.h > > @@ -422,36 +422,94 @@ static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t fla > > return false; > > } > > > > +#ifdef CONFIG_SLAB_OBJ_EXT > > + > > +static inline bool is_kmem_only_obj_ext(void) > > +{ > > #ifdef CONFIG_MEMCG_KMEM > > + return sizeof(struct slabobj_ext) == sizeof(struct obj_cgroup *); > > +#else > > + return false; > > +#endif > > +} > > + > > /* > > - * slab_objcgs - get the object cgroups vector associated with a slab > > + * slab_obj_exts - get the pointer to the slab object extension vector > > + * associated with a slab. > > * @slab: a pointer to the slab struct > > * > > - * Returns a pointer to the object cgroups vector associated with the slab, > > + * Returns a pointer to the object extension vector associated with the slab, > > * or NULL if no such vector has been associated yet. > > */ > > -static inline struct obj_cgroup **slab_objcgs(struct slab *slab) > > +static inline struct slabobj_ext *slab_obj_exts(struct slab *slab) > > { > > unsigned long memcg_data = READ_ONCE(slab->memcg_data); > > > > - VM_BUG_ON_PAGE(memcg_data && !(memcg_data & MEMCG_DATA_OBJCGS), > > + VM_BUG_ON_PAGE(memcg_data && !(memcg_data & MEMCG_DATA_OBJEXTS), > > slab_page(slab)); > > VM_BUG_ON_PAGE(memcg_data & MEMCG_DATA_KMEM, slab_page(slab)); > > > > - return (struct obj_cgroup **)(memcg_data & ~MEMCG_DATA_FLAGS_MASK); > > + return (struct slabobj_ext *)(memcg_data & ~MEMCG_DATA_FLAGS_MASK); > > } > > > > -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); > > +int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s, > > + gfp_t gfp, bool new_slab); > > > > -static inline void memcg_free_slab_cgroups(struct slab *slab) > > +static inline void free_slab_obj_exts(struct slab *slab) > > { > > - kfree(slab_objcgs(slab)); > > + struct slabobj_ext *obj_exts; > > + > > + if (!memcg_kmem_enabled() && is_kmem_only_obj_ext()) > > + return; > > Hm, not sure I understand this. I kmem is disabled and is_kmem_only_obj_ext() > is true, shouldn't slab->memcg_data == NULL (always)? So, the logic was to skip freeing when the only possible objects in slab->memcg_data are "struct obj_cgroup" and kmem is disabled. Otherwise there are other objects stored in slab->memcg_data which have to be freed. Did I make it more complicated than it should have been? > > > + > > + obj_exts = slab_obj_exts(slab); > > + kfree(obj_exts); > > slab->memcg_data = 0; > > } > > > > +static inline void prepare_slab_obj_exts_hook(struct kmem_cache *s, gfp_t flags, void *p) > > +{ > > + struct slab *slab; > > + > > + /* If kmem is the only extension then the vector will be created conditionally */ > > + if (is_kmem_only_obj_ext()) > > + return; > > + > > + slab = virt_to_slab(p); > > + if (!slab_obj_exts(slab)) > > + WARN(alloc_slab_obj_exts(slab, s, flags, false), > > + "%s, %s: Failed to create slab extension vector!\n", > > + __func__, s->name); > > +} > > This looks a bit crypric: the action is wrapped into WARN() and the rest is a set > of (semi-)static checks. Can we, please, invert it? E.g. something like: > > if (slab_alloc_tracking_enabled()) { > slab = virt_to_slab(p); > if (!slab_obj_exts(slab)) > WARN(alloc_slab_obj_exts(slab, s, flags, false), > "%s, %s: Failed to create slab extension vector!\n", > __func__, s->name); > } Yeah, this is much more readable. Thanks for the suggestion and for reviewing the code! > > The rest looks good to me. > > Thank you! > > -- > To unsubscribe from this group and stop receiving emails from it, send an email to kernel-team+unsubscribe@android.com. >
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 6257867fbf95..315399f77173 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -227,6 +227,14 @@ struct obj_cgroup { }; }; +/* + * Extended information for slab objects stored as an array in page->memcg_data + * if MEMCG_DATA_OBJEXTS is set. + */ +struct slabobj_ext { + struct obj_cgroup *objcg; +} __aligned(8); + /* * The memory controller data structure. The memory controller controls both * page cache and RSS per cgroup. We would eventually like to provide @@ -363,7 +371,7 @@ extern struct mem_cgroup *root_mem_cgroup; enum page_memcg_data_flags { /* page->memcg_data is a pointer to an objcgs vector */ - MEMCG_DATA_OBJCGS = (1UL << 0), + MEMCG_DATA_OBJEXTS = (1UL << 0), /* page has been accounted as a non-slab kernel page */ MEMCG_DATA_KMEM = (1UL << 1), /* the next bit after the last actual flag */ @@ -401,7 +409,7 @@ static inline struct mem_cgroup *__folio_memcg(struct folio *folio) unsigned long memcg_data = folio->memcg_data; VM_BUG_ON_FOLIO(folio_test_slab(folio), folio); - VM_BUG_ON_FOLIO(memcg_data & MEMCG_DATA_OBJCGS, folio); + VM_BUG_ON_FOLIO(memcg_data & MEMCG_DATA_OBJEXTS, folio); VM_BUG_ON_FOLIO(memcg_data & MEMCG_DATA_KMEM, folio); return (struct mem_cgroup *)(memcg_data & ~MEMCG_DATA_FLAGS_MASK); @@ -422,7 +430,7 @@ static inline struct obj_cgroup *__folio_objcg(struct folio *folio) unsigned long memcg_data = folio->memcg_data; VM_BUG_ON_FOLIO(folio_test_slab(folio), folio); - VM_BUG_ON_FOLIO(memcg_data & MEMCG_DATA_OBJCGS, folio); + VM_BUG_ON_FOLIO(memcg_data & MEMCG_DATA_OBJEXTS, folio); VM_BUG_ON_FOLIO(!(memcg_data & MEMCG_DATA_KMEM), folio); return (struct obj_cgroup *)(memcg_data & ~MEMCG_DATA_FLAGS_MASK); @@ -517,7 +525,7 @@ static inline struct mem_cgroup *page_memcg_check(struct page *page) */ unsigned long memcg_data = READ_ONCE(page->memcg_data); - if (memcg_data & MEMCG_DATA_OBJCGS) + if (memcg_data & MEMCG_DATA_OBJEXTS) return NULL; if (memcg_data & MEMCG_DATA_KMEM) { @@ -556,7 +564,7 @@ static inline struct mem_cgroup *get_mem_cgroup_from_objcg(struct obj_cgroup *ob static inline bool folio_memcg_kmem(struct folio *folio) { VM_BUG_ON_PGFLAGS(PageTail(&folio->page), &folio->page); - VM_BUG_ON_FOLIO(folio->memcg_data & MEMCG_DATA_OBJCGS, folio); + VM_BUG_ON_FOLIO(folio->memcg_data & MEMCG_DATA_OBJEXTS, folio); return folio->memcg_data & MEMCG_DATA_KMEM; } diff --git a/init/Kconfig b/init/Kconfig index 532362fcfe31..82396d7a2717 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -958,6 +958,10 @@ config MEMCG help Provides control over the memory footprint of tasks in a cgroup. +config SLAB_OBJ_EXT + bool + depends on MEMCG + config MEMCG_SWAP bool depends on MEMCG && SWAP @@ -966,6 +970,7 @@ config MEMCG_SWAP config MEMCG_KMEM bool depends on MEMCG && !SLOB + select SLAB_OBJ_EXT default y config BLK_CGROUP diff --git a/mm/kfence/core.c b/mm/kfence/core.c index c252081b11df..c0958e4a32e2 100644 --- a/mm/kfence/core.c +++ b/mm/kfence/core.c @@ -569,7 +569,7 @@ static unsigned long kfence_init_pool(void) __folio_set_slab(slab_folio(slab)); #ifdef CONFIG_MEMCG slab->memcg_data = (unsigned long)&kfence_metadata[i / 2 - 1].objcg | - MEMCG_DATA_OBJCGS; + MEMCG_DATA_OBJEXTS; #endif } diff --git a/mm/memcontrol.c b/mm/memcontrol.c index b69979c9ced5..3f407ef2f3f1 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2793,7 +2793,7 @@ static void commit_charge(struct folio *folio, struct mem_cgroup *memcg) folio->memcg_data = (unsigned long)memcg; } -#ifdef CONFIG_MEMCG_KMEM +#ifdef CONFIG_SLAB_OBJ_EXT /* * The allocated objcg pointers array is not accounted directly. * Moreover, it should not come from DMA buffer and is not readily @@ -2801,38 +2801,20 @@ static void commit_charge(struct folio *folio, struct mem_cgroup *memcg) */ #define OBJCGS_CLEAR_MASK (__GFP_DMA | __GFP_RECLAIMABLE | __GFP_ACCOUNT) -/* - * mod_objcg_mlstate() may be called with irq enabled, so - * mod_memcg_lruvec_state() should be used. - */ -static inline void mod_objcg_mlstate(struct obj_cgroup *objcg, - struct pglist_data *pgdat, - enum node_stat_item idx, int nr) -{ - struct mem_cgroup *memcg; - struct lruvec *lruvec; - - rcu_read_lock(); - memcg = obj_cgroup_memcg(objcg); - lruvec = mem_cgroup_lruvec(memcg, pgdat); - mod_memcg_lruvec_state(lruvec, idx, nr); - rcu_read_unlock(); -} - -int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s, - gfp_t gfp, bool new_slab) +int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s, + gfp_t gfp, bool new_slab) { unsigned int objects = objs_per_slab(s, slab); unsigned long memcg_data; void *vec; gfp &= ~OBJCGS_CLEAR_MASK; - vec = kcalloc_node(objects, sizeof(struct obj_cgroup *), gfp, + vec = kcalloc_node(objects, sizeof(struct slabobj_ext), gfp, slab_nid(slab)); if (!vec) return -ENOMEM; - memcg_data = (unsigned long) vec | MEMCG_DATA_OBJCGS; + memcg_data = (unsigned long) vec | MEMCG_DATA_OBJEXTS; if (new_slab) { /* * If the slab is brand new and nobody can yet access its @@ -2843,7 +2825,7 @@ int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s, } else if (cmpxchg(&slab->memcg_data, 0, memcg_data)) { /* * If the slab is already in use, somebody can allocate and - * assign obj_cgroups in parallel. In this case the existing + * assign slabobj_exts in parallel. In this case the existing * objcg vector should be reused. */ kfree(vec); @@ -2853,6 +2835,26 @@ int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s, kmemleak_not_leak(vec); return 0; } +#endif /* CONFIG_SLAB_OBJ_EXT */ + +#ifdef CONFIG_MEMCG_KMEM +/* + * mod_objcg_mlstate() may be called with irq enabled, so + * mod_memcg_lruvec_state() should be used. + */ +static inline void mod_objcg_mlstate(struct obj_cgroup *objcg, + struct pglist_data *pgdat, + enum node_stat_item idx, int nr) +{ + struct mem_cgroup *memcg; + struct lruvec *lruvec; + + rcu_read_lock(); + memcg = obj_cgroup_memcg(objcg); + lruvec = mem_cgroup_lruvec(memcg, pgdat); + mod_memcg_lruvec_state(lruvec, idx, nr); + rcu_read_unlock(); +} static __always_inline struct mem_cgroup *mem_cgroup_from_obj_folio(struct folio *folio, void *p) @@ -2863,18 +2865,18 @@ struct mem_cgroup *mem_cgroup_from_obj_folio(struct folio *folio, void *p) * slab->memcg_data. */ if (folio_test_slab(folio)) { - struct obj_cgroup **objcgs; + struct slabobj_ext *obj_exts; struct slab *slab; unsigned int off; slab = folio_slab(folio); - objcgs = slab_objcgs(slab); - if (!objcgs) + obj_exts = slab_obj_exts(slab); + if (!obj_exts) return NULL; off = obj_to_index(slab->slab_cache, slab, p); - if (objcgs[off]) - return obj_cgroup_memcg(objcgs[off]); + if (obj_exts[off].objcg) + return obj_cgroup_memcg(obj_exts[off].objcg); return NULL; } diff --git a/mm/page_owner.c b/mm/page_owner.c index e4c6f3f1695b..fd4af1ad34b8 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -353,7 +353,7 @@ static inline int print_page_owner_memcg(char *kbuf, size_t count, int ret, if (!memcg_data) goto out_unlock; - if (memcg_data & MEMCG_DATA_OBJCGS) + if (memcg_data & MEMCG_DATA_OBJEXTS) ret += scnprintf(kbuf + ret, count - ret, "Slab cache page\n"); diff --git a/mm/slab.h b/mm/slab.h index 4ec82bec15ec..c767ce3f0fe2 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -422,36 +422,94 @@ static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t fla return false; } +#ifdef CONFIG_SLAB_OBJ_EXT + +static inline bool is_kmem_only_obj_ext(void) +{ #ifdef CONFIG_MEMCG_KMEM + return sizeof(struct slabobj_ext) == sizeof(struct obj_cgroup *); +#else + return false; +#endif +} + /* - * slab_objcgs - get the object cgroups vector associated with a slab + * slab_obj_exts - get the pointer to the slab object extension vector + * associated with a slab. * @slab: a pointer to the slab struct * - * Returns a pointer to the object cgroups vector associated with the slab, + * Returns a pointer to the object extension vector associated with the slab, * or NULL if no such vector has been associated yet. */ -static inline struct obj_cgroup **slab_objcgs(struct slab *slab) +static inline struct slabobj_ext *slab_obj_exts(struct slab *slab) { unsigned long memcg_data = READ_ONCE(slab->memcg_data); - VM_BUG_ON_PAGE(memcg_data && !(memcg_data & MEMCG_DATA_OBJCGS), + VM_BUG_ON_PAGE(memcg_data && !(memcg_data & MEMCG_DATA_OBJEXTS), slab_page(slab)); VM_BUG_ON_PAGE(memcg_data & MEMCG_DATA_KMEM, slab_page(slab)); - return (struct obj_cgroup **)(memcg_data & ~MEMCG_DATA_FLAGS_MASK); + return (struct slabobj_ext *)(memcg_data & ~MEMCG_DATA_FLAGS_MASK); } -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); +int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s, + gfp_t gfp, bool new_slab); -static inline void memcg_free_slab_cgroups(struct slab *slab) +static inline void free_slab_obj_exts(struct slab *slab) { - kfree(slab_objcgs(slab)); + struct slabobj_ext *obj_exts; + + if (!memcg_kmem_enabled() && is_kmem_only_obj_ext()) + return; + + obj_exts = slab_obj_exts(slab); + kfree(obj_exts); slab->memcg_data = 0; } +static inline void prepare_slab_obj_exts_hook(struct kmem_cache *s, gfp_t flags, void *p) +{ + struct slab *slab; + + /* If kmem is the only extension then the vector will be created conditionally */ + if (is_kmem_only_obj_ext()) + return; + + slab = virt_to_slab(p); + if (!slab_obj_exts(slab)) + WARN(alloc_slab_obj_exts(slab, s, flags, false), + "%s, %s: Failed to create slab extension vector!\n", + __func__, s->name); +} + +#else /* CONFIG_SLAB_OBJ_EXT */ + +static inline struct slabobj_ext *slab_obj_exts(struct slab *slab) +{ + return NULL; +} + +static inline int alloc_slab_obj_exts(struct slab *slab, + struct kmem_cache *s, gfp_t gfp, + bool new_slab) +{ + return 0; +} + +static inline void free_slab_obj_exts(struct slab *slab) +{ +} + +static inline void prepare_slab_obj_exts_hook(struct kmem_cache *s, gfp_t flags, void *p) +{ +} + +#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); + static inline size_t obj_full_size(struct kmem_cache *s) { /* @@ -519,16 +577,15 @@ static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s, if (likely(p[i])) { slab = virt_to_slab(p[i]); - if (!slab_objcgs(slab) && - memcg_alloc_slab_cgroups(slab, s, flags, - false)) { + if (!slab_obj_exts(slab) && + alloc_slab_obj_exts(slab, s, flags, false)) { obj_cgroup_uncharge(objcg, obj_full_size(s)); continue; } off = obj_to_index(s, slab, p[i]); obj_cgroup_get(objcg); - slab_objcgs(slab)[off] = objcg; + slab_obj_exts(slab)[off].objcg = objcg; mod_objcg_state(objcg, slab_pgdat(slab), cache_vmstat_idx(s), obj_full_size(s)); } else { @@ -541,14 +598,14 @@ static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s, static inline void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab, void **p, int objects) { - struct obj_cgroup **objcgs; + struct slabobj_ext *obj_exts; int i; if (!memcg_kmem_enabled()) return; - objcgs = slab_objcgs(slab); - if (!objcgs) + obj_exts = slab_obj_exts(slab); + if (!obj_exts) return; for (i = 0; i < objects; i++) { @@ -556,11 +613,11 @@ static inline void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab, unsigned int off; off = obj_to_index(s, slab, p[i]); - objcg = objcgs[off]; + objcg = obj_exts[off].objcg; if (!objcg) continue; - objcgs[off] = NULL; + obj_exts[off].objcg = NULL; obj_cgroup_uncharge(objcg, obj_full_size(s)); mod_objcg_state(objcg, slab_pgdat(slab), cache_vmstat_idx(s), -obj_full_size(s)); @@ -569,27 +626,11 @@ static inline void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab, } #else /* CONFIG_MEMCG_KMEM */ -static inline struct obj_cgroup **slab_objcgs(struct slab *slab) -{ - return NULL; -} - static inline struct mem_cgroup *memcg_from_slab_obj(void *ptr) { return NULL; } -static inline int memcg_alloc_slab_cgroups(struct slab *slab, - struct kmem_cache *s, gfp_t gfp, - bool new_slab) -{ - return 0; -} - -static inline void memcg_free_slab_cgroups(struct slab *slab) -{ -} - static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s, struct list_lru *lru, struct obj_cgroup **objcgp, @@ -627,7 +668,7 @@ static __always_inline void account_slab(struct slab *slab, int order, struct kmem_cache *s, gfp_t gfp) { if (memcg_kmem_enabled() && (s->flags & SLAB_ACCOUNT)) - memcg_alloc_slab_cgroups(slab, s, gfp, true); + alloc_slab_obj_exts(slab, s, gfp, true); mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s), PAGE_SIZE << order); @@ -636,8 +677,7 @@ 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_enabled()) - memcg_free_slab_cgroups(slab); + free_slab_obj_exts(slab); mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s), -(PAGE_SIZE << order)); @@ -729,6 +769,7 @@ static inline void slab_post_alloc_hook(struct kmem_cache *s, memset(p[i], 0, s->object_size); kmemleak_alloc_recursive(p[i], s->object_size, 1, s->flags, flags); + prepare_slab_obj_exts_hook(s, flags, p[i]); } memcg_slab_post_alloc_hook(s, objcg, flags, size, p);
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. Wraps obj_cgroup into slabobj_ext to support current functionality while allowing to extend slabobj_ext in the future. Note: ideally the config dependency should be turned the other way around: MEMCG should depend on SLAB_OBJ_EXT and {page|slab|folio}.memcg_data would be renamed to something like {page|slab|folio}.objext_data. However doing this in RFC would introduce considerable churn unrelated to the overall idea, so avoiding this until v1. Signed-off-by: Suren Baghdasaryan <surenb@google.com> --- include/linux/memcontrol.h | 18 ++++-- init/Kconfig | 5 ++ mm/kfence/core.c | 2 +- mm/memcontrol.c | 60 ++++++++++--------- mm/page_owner.c | 2 +- mm/slab.h | 119 +++++++++++++++++++++++++------------ 6 files changed, 131 insertions(+), 75 deletions(-)