| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Mon, 26 Feb 2024 17:22:21 +0000
From: Suren Baghdasaryan <surenb@...gle.com>
To: Vlastimil Babka <vbabka@...e.cz>
Cc: akpm@...ux-foundation.org, kent.overstreet@...ux.dev, mhocko@...e.com,
hannes@...xchg.org, roman.gushchin@...ux.dev, mgorman@...e.de,
dave@...olabs.net, willy@...radead.org, liam.howlett@...cle.com,
penguin-kernel@...ove.sakura.ne.jp, corbet@....net, void@...ifault.com,
peterz@...radead.org, juri.lelli@...hat.com, catalin.marinas@....com,
will@...nel.org, arnd@...db.de, tglx@...utronix.de, mingo@...hat.com,
dave.hansen@...ux.intel.com, x86@...nel.org, peterx@...hat.com,
david@...hat.com, axboe@...nel.dk, mcgrof@...nel.org, masahiroy@...nel.org,
nathan@...nel.org, dennis@...nel.org, tj@...nel.org, muchun.song@...ux.dev,
rppt@...nel.org, paulmck@...nel.org, pasha.tatashin@...een.com,
yosryahmed@...gle.com, yuzhao@...gle.com, dhowells@...hat.com,
hughd@...gle.com, andreyknvl@...il.com, keescook@...omium.org,
ndesaulniers@...gle.com, vvvvvv@...gle.com, gregkh@...uxfoundation.org,
ebiggers@...gle.com, ytcoode@...il.com, vincent.guittot@...aro.org,
dietmar.eggemann@....com, rostedt@...dmis.org, bsegall@...gle.com,
bristot@...hat.com, vschneid@...hat.com, cl@...ux.com, penberg@...nel.org,
iamjoonsoo.kim@....com, 42.hyeyoo@...il.com, glider@...gle.com,
elver@...gle.com, dvyukov@...gle.com, shakeelb@...gle.com,
songmuchun@...edance.com, jbaron@...mai.com, rientjes@...gle.com,
minchan@...gle.com, kaleshsingh@...gle.com, kernel-team@...roid.com,
linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org,
iommu@...ts.linux.dev, linux-arch@...r.kernel.org,
linux-fsdevel@...r.kernel.org, linux-mm@...ck.org,
linux-modules@...r.kernel.org, kasan-dev@...glegroups.com,
cgroups@...r.kernel.org
Subject: Re: [PATCH v4 07/36] mm: introduce slabobj_ext to support slab object extensions
On Mon, Feb 26, 2024 at 8:26 AM Vlastimil Babka <vbabka@...e.cz> 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@...gle.com>
>
> 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));
>
Powered by blists - more mailing lists