RE: [PATCH 4/4] mm/slab: move slab merge from slab_common.c to slub.c

["Song, Xiongwei" <Xiongwei.Song@windriver.com>]

> -----Original Message-----
> From: owner-linux-mm@kvack.org <owner-linux-mm@kvack.org> On Behalf Of Vlastimil
> Babka
> Sent: Tuesday, November 21, 2023 6:03 PM
> To: Hyeonggon Yoo <42.hyeyoo@gmail.com>; sxwjean@me.com
> Cc: cl@linux.com; penberg@kernel.org; rientjes@google.com; iamjoonsoo.kim@lge.com;
> roman.gushchin@linux.dev; corbet@lwn.net; linux-mm@kvack.org; linux-
> doc@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH 4/4] mm/slab: move slab merge from slab_common.c to slub.c
> 
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> On 11/21/23 09:54, Hyeonggon Yoo wrote:
> > On Mon, Nov 20, 2023 at 6:13 PM <sxwjean@me.com> wrote:
> >>
> >> From: Xiongwei Song <xiongwei.song@windriver.com>
> >>
> >> Since slab allocator has been removed. There is no users about slab
> >> merge except slub. This commit is almost to revert
> >> commit 423c929cbbec ("mm/slab_common: commonize slab merge logic").
> >>
> >> Also change all prefix of slab merge related functions, variables and
> >> definitions from "slab/SLAB" to"slub/SLUB".
> >
> > Could you please elaborate a little bit?
> > I am not sure if I understand what the last two patches of this series
> > are useful for.
> >
> > - Why rename variable/function/macro names?
> > - Why move merge related functions from slab_common.c to slub.c?
> 
> In my series I have moved functions that were part of allocation/free hot
> paths as there should be performance benefits if they are all in the same
> compilation unit.
> 
> >   (I mean merging slab_common.c and slub.c into single file might make sense
> >    but why move only some parts of one into the other?)
> 
> OTOH slub.c becomes quite big, so I think it would make sense to not merge
> mm/slab_common.c fully. The non-hot code that's handling e.g. the caches
> creation and management, such as what this patch is moving, could certainly
> stay away from mm/slub.c. We could just pick a more descriptive name for
> slab_common.c.
> 
> I'd even investigate if more parts of slub.c could be split out (to a new
> file/files) without compromising the hot paths, i.e. sysfs, debugging etc.

Ok, sure. Sounds good.

Regards,
Xiongwei