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Date:   Fri, 1 Dec 2023 09:47:42 -0800
From:   Kees Cook <keescook@chromium.org>
To:     sxwjean@me.com
Cc:     vbabka@suse.cz, 42.hyeyoo@gmail.com, cl@linux.com,
        linux-mm@kvack.org, penberg@kernel.org, rientjes@google.com,
        iamjoonsoo.kim@lge.com, roman.gushchin@linux.dev, corbet@lwn.net,
        arnd@arndb.de, akpm@linux-foundation.org,
        gregkh@linuxfoundation.org, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Xiongwei Song <xiongwei.song@windriver.com>
Subject: Re: [RFC PATCH 2/3] mm/slub: unify all sl[au]b parameters with
 "slab_$param"
Message-ID: <202312010945.7C5DB1FBB@keescook>
References: <20231201031505.286117-1-sxwjean@me.com>
 <20231201031505.286117-3-sxwjean@me.com>
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On Fri, Dec 01, 2023 at 11:15:04AM +0800, sxwjean@me.com wrote:
> From: Xiongwei Song <xiongwei.song@windriver.com>
> 
> Since the SLAB allocator has been removed, so we need to clean up the
> sl[au]b_$params. However, the "slab/SLAB" terms should be keep for
> long-term rather than "slub/SLUB". Hence, we should use "slab_$param"
> as the primary prefix, which is pointed out by Vlastimil Babka. For more
> information please see [1].
> 
> This patch is changing the following slab parameters
> - slub_max_order
> - slub_min_order
> - slub_min_objects
> - slub_debug
> to
> - slab_max_order
> - slab_min_order
> - slab_min_objects
> - slab_debug
> as the primary slab parameters in
> Documentation/admin-guide/kernel-parameters.txt and source, and rename all
> setup functions of them too. Meanwhile, "slub_$params" can also be passed
> by command line, which is to keep backward compatibility. Also mark all
> "slub_$params" as legacy.

*If* we do this, I think the old names need to be recognized, perhaps
with a boot pr_warn() about their deprecation/renaming for several
releases (likely across LTSes). I think it's not a good idea to
wholesale rename these with no warning. That's going to cause a lot of
surprises and broken userspace...

-- 
Kees Cook