From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9DE88C433EF for ; Mon, 27 Sep 2021 09:03:54 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 42BBD6103B for ; Mon, 27 Sep 2021 09:03:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 42BBD6103B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 906056B0071; Mon, 27 Sep 2021 05:03:53 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8B5F6900002; Mon, 27 Sep 2021 05:03:53 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7CBB06B0073; Mon, 27 Sep 2021 05:03:53 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0075.hostedemail.com [216.40.44.75]) by kanga.kvack.org (Postfix) with ESMTP id 70AE16B0071 for ; Mon, 27 Sep 2021 05:03:53 -0400 (EDT) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 2D0063206F for ; Mon, 27 Sep 2021 09:03:53 +0000 (UTC) X-FDA: 78632765946.20.38104DD Received: from mail-pj1-f53.google.com (mail-pj1-f53.google.com [209.85.216.53]) by imf01.hostedemail.com (Postfix) with ESMTP id EA7395065673 for ; Mon, 27 Sep 2021 09:03:52 +0000 (UTC) Received: by mail-pj1-f53.google.com with SMTP id k23so11998134pji.0 for ; Mon, 27 Sep 2021 02:03:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:mime-version:content-disposition; bh=fsM8DSW8COr9yjZjuQ8R7r+/Zwj6TnS2NlS6vkV0T3s=; b=fBt2WUdedT/b+XMGkk9EfRphHxJxR9zHYhs89nFhZkz55W92U7p0NpBfyW0zqGJpwP j2uq8q1Lep4fricDOV346ROxvq86TQPcEZEePRftxaqCJRpVgvw6EioiPUj9lgHpl3nl nvdxuD8DT/KRXLZiHac9Ej/mAlclfEQpY8qJR3Zg+EYWuXgIezfOpW0gsRo84N79aK6n D+hiFRBHY9WWHQYBTSC6InTMCjCKHJ2TiTZP4tGVqZdgg6TurTZjQOU/lwvW9rbieP7m rP3aE1d7fSFLu+Tt86nRae96GxyfLif6A1WhY1LAUombcCbd4F/SZUMX8khkc/BABCdC x2QA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:mime-version :content-disposition; bh=fsM8DSW8COr9yjZjuQ8R7r+/Zwj6TnS2NlS6vkV0T3s=; b=iMVLfQhMT39SVVwiabxgHFTN37QV+DQCeqV2F7S4LNM6mH0kCBl6cQyH6s/oDaFYhG dKw1fUNS50Q5wvMypuABZbyu3DQG5l868kaL8FhHu9GGl5FIbMmGCh0gbkZoXq3peB8b YAfFUiZJUA647/4dhcM46GqhmsYXyXemUTr7WDIUpFfdopp3rATHvk/PmUb7vK5xpPSS 1TYTtbu5ld2FUAjDIijOJVFRVRYDyoQVReum0Zmpliy+pUzoi7yuARj4oUXB3r2HvE0D wkTKG15gZ0mfvjlzpcbmSTfzsXQLZK3/d9FMRSfmlkWOx/vZBtoDugYZwXg3dDcsEzWY ZuTg== X-Gm-Message-State: AOAM533r16LNxJT0Ib6qEHhpZ+R7MFfJObfJuPrCkSI/e1AHFnb1TNoB 1mPY8F2uhAIcsnBRhOWsNQJyOybtC0U= X-Google-Smtp-Source: ABdhPJzfog+s1xblddJ/ixdQcD4E5XG8K9081mfU4t0av0LFMgspl8yS5uegoma4VNrU8CcaoLZktw== X-Received: by 2002:a17:90a:9310:: with SMTP id p16mr18418730pjo.204.1632733431683; Mon, 27 Sep 2021 02:03:51 -0700 (PDT) Received: from linux.asia-northeast3-a.c.our-ratio-313919.internal (252.229.64.34.bc.googleusercontent.com. [34.64.229.252]) by smtp.gmail.com with ESMTPSA id p189sm16352293pfp.167.2021.09.27.02.03.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Sep 2021 02:03:51 -0700 (PDT) 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 , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Vlastimil Babka , 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: EA7395065673 X-Stat-Signature: xnbbzqwh7fc7t886it8fhcwu5e5mia7b Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=fBt2WUde; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf01.hostedemail.com: domain of 42.hyeyoo@gmail.com designates 209.85.216.53 as permitted sender) smtp.mailfrom=42.hyeyoo@gmail.com X-HE-Tag: 1632733432-236965 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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