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Date:   Mon, 27 Sep 2021 09:03:47 +0000
From:   Hyeonggon Yoo <42.hyeyoo@gmail.com>
To:     linux-mm@kvack.org
Cc:     42.hyeyoo@gmail.com, Christoph Lameter <cl@linux.com>,
        Pekka Enberg <penberg@kernel.org>,
        David Rientjes <rientjes@google.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Vlastimil Babka <vbabka@suse.cz>, linux-kernel@vger.kernel.org
Subject: [QUESTION] is SLAB considered legacy and deprecated?
Message-ID: <20210927090347.GA2533@linux.asia-northeast3-a.c.our-ratio-313919.internal>
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Hello there,

I've been working on adding 'lockless cache' on sl[au]b for a while.
But what it actually does is actually adding 'queuing' on slub.

So there is a fundamental question coming into my mind:
	'is SLAB considered legacy and deprecated?'

It seems there are little development on SLAB and people think that
SLAB is legacy and deprecated, so CONFIG_SLUB is used by default.

But I think both has pros and cons for their own:
	SLAB: more temporal locality (cache friendly)
	but high usage of memory, and less spatial locality (TLB misses) than SLUB.

	SLUB: less temporal locality (less cache friendly) than SLAB
	but more spatial locality (TLB hit), and low usage of memory
	and good debugging feature.

Why do people say SLAB is deprecated/legacy?

Thanks,
Hyeonggon