On Sun, Jun 05, 2022 at 03:04:44PM +0800, Xiongwei Song wrote: > On Sat, Jun 4, 2022 at 5:43 PM Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx> wrote: > > > > On Fri, Jun 03, 2022 at 10:35:55PM +0800, sxwjean@xxxxxx wrote: > > > From: Xiongwei Song <xiongwei.song@xxxxxxxxxxxxx> > > > > > > There is no need to do anything if sysfs_slab_alias() return nonzero > > > value after getting a mergeable cache. > > > > > > Signed-off-by: Xiongwei Song <xiongwei.song@xxxxxxxxxxxxx> > > > Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> > > > --- > > > v2: Collect Reviewed-by tag from Muchun. > > > --- > > > mm/slub.c | 8 +++----- > > > 1 file changed, 3 insertions(+), 5 deletions(-) > > > > > > diff --git a/mm/slub.c b/mm/slub.c > > > index d8d5abf49f5f..9444277d669a 100644 > > > --- a/mm/slub.c > > > +++ b/mm/slub.c > > > @@ -4861,6 +4861,9 @@ __kmem_cache_alias(const char *name, unsigned int size, unsigned int align, > > > > > > s = find_mergeable(size, align, flags, name, ctor); > > > if (s) { > > > + if (sysfs_slab_alias(s, name)) > > > + return NULL; > > > + > > > s->refcount++; > > > > > > > I think we should not expose sysfs attributes before initializing > > what can be read via sysfs attribute (object_size). > > > > > /* > > > @@ -4869,11 +4872,6 @@ __kmem_cache_alias(const char *name, unsigned int size, unsigned int align, > > > */ > > > s->object_size = max(s->object_size, size); > > > > this calculation should be done before sysfs_slab_alias(). > Sorry for the late reply. > Yeah, understood. Should we restore s->object_size and s->inuse if > sysfs_slab_alias() returns non zero value? In my opinion, yes. Thanks, Hyeonggon > Regards, > Xiongwwei > > > > > Thanks, > > Hyeonggon > > > > > s->inuse = max(s->inuse, ALIGN(size, sizeof(void *))); > > > - > > > - if (sysfs_slab_alias(s, name)) { > > > - s->refcount--; > > > - s = NULL; > > > - } > > > } > > > > > > return s; > > > -- > > > 2.30.2 > > > > > -- Thanks, Hyeonggon