Re: [PATCH v2 12/15] slab: create kmem_cache_create() compatibility layer

[Mike Rapoport <rppt@kernel.org>]

On Wed, Sep 04, 2024 at 04:44:03PM +0200, Christian Brauner wrote:
> On Wed, Sep 04, 2024 at 03:33:30PM GMT, Vlastimil Babka wrote:
> > On 9/4/24 13:38, Christian Brauner wrote:
> > > On Wed, Sep 04, 2024 at 12:50:28PM GMT, Vlastimil Babka wrote:
> > >> On 9/4/24 11:45, Christian Brauner wrote:
> > >> > On Wed, Sep 04, 2024 at 08:14:24AM GMT, Mike Rapoport wrote:
> > >> >> On Tue, Sep 03, 2024 at 04:20:53PM +0200, Christian Brauner wrote:
> > >> >> > Use _Generic() to create a compatibility layer that type switches on the
> > >> >> > third argument to either call __kmem_cache_create() or
> > >> >> > __kmem_cache_create_args(). This can be kept in place until all callers
> > >> >> > have been ported to struct kmem_cache_args.
> > >> >> > 
> > >> >> > Signed-off-by: Christian Brauner <brauner@kernel.org>
> > >> >> 
> > >> >> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> > >> >> 
> > >> >> > ---
> > >> >> >  include/linux/slab.h | 13 ++++++++++---
> > >> >> >  mm/slab_common.c     | 10 +++++-----
> > >> >> >  2 files changed, 15 insertions(+), 8 deletions(-)
> > >> >> > 
> > >> >> > diff --git a/include/linux/slab.h b/include/linux/slab.h
> > >> >> > index aced16a08700..4292d67094c3 100644
> > >> >> > --- a/include/linux/slab.h
> > >> >> > +++ b/include/linux/slab.h
> > >> >> > @@ -261,9 +261,10 @@ struct kmem_cache *__kmem_cache_create_args(const char *name,
> > >> >> >  					    unsigned int object_size,
> > >> >> >  					    struct kmem_cache_args *args,
> > >> >> >  					    slab_flags_t flags);
> > >> >> > -struct kmem_cache *kmem_cache_create(const char *name, unsigned int size,
> > >> >> > -			unsigned int align, slab_flags_t flags,
> > >> >> > -			void (*ctor)(void *));
> > >> >> > +
> > >> >> > +struct kmem_cache *__kmem_cache_create(const char *name, unsigned int size,
> > >> >> > +				       unsigned int align, slab_flags_t flags,
> > >> >> > +				       void (*ctor)(void *));
> > >> >> 
> > >> >> As I said earlier, this can become _kmem_cache_create and
> > >> >> __kmem_cache_create_args can be __kmem_cache_create from the beginning.
> > >> 
> > >> I didn't notice an answer to this suggestion? Even if it's just that you
> > >> don't think it's worth the rewrite, or it's not possible because X Y Z.
> > >> Thanks.
> > > 
> > > I'm confused. I sent two patches as a reply to the thread plus the
> > > answer below and there's two patches in v3 that you can use or drop.
> > 
> > Right, that's the part below. But the suggestion above, and also in Mike's
> > reply to 02/12 was AFAICS to rename __kmem_cache_create_args to
> > __kmem_cache_create (since patch 02) and here __kmem_cache_create to
> > _kmem_cache_create. It just seemed odd to see no reaction to that (did I
> > miss or not receive it?).
> 
> Oh, I see. I read it as a expressing taste and so I didn't bother
> replying. And I really dislike single underscore function names so I
> would like to avoid it and it also seems more confusing to me.

Heh, not quite. I don't like kmem_cache_create_args essentially becoming a
replacement for kmem_cache_create* and I'd prefer __kmem_cache_create
naming.

As for the single underscore, I don't have strong feelings about it, but I
do think that it should be renamed to something else than
__kmem_cache_create to leave __kmem_cache_create for the core function.

-- 
Sincerely yours,
Mike.