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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D2C45C9830E for ; Thu, 24 Sep 2026 15:19:02 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A9EFB6B008C; Thu, 24 Sep 2026 11:19:01 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A28D56B0092; Thu, 24 Sep 2026 11:19:01 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8F0F76B0093; Thu, 24 Sep 2026 11:19:01 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 6FE2C6B008C for ; Thu, 24 Sep 2026 11:19:01 -0400 (EDT) Received: from smtpin14.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 056CE402E3 for ; Thu, 24 Sep 2026 15:19:01 +0000 (UTC) X-FDA: 85249013682.14.1462019 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf11.hostedemail.com (Postfix) with ESMTP id 68EA540011 for ; Thu, 24 Sep 2026 15:18:59 +0000 (UTC) Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=VVDH9WLs; spf=pass (imf11.hostedemail.com: domain of harry@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=harry@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1790263139; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=r7s1CAgd45i1qVFJKno+reNnGoGUQMAT+I7uYiP/nks=; b=xCskSODUhsMKPHeIQnj7i7kXI3f/y0Z7U1JPHiSkFvMULrkiuOGhCQWORUcjgYUyXTz5CR L0YS6WzzMaBQkYerucy2e29P3+sSL2ryDY8t0QixRhHr2KuZq0tTVEAd489XNDULw4wZ7C Lfgx2M5f4CdYgYu/vPbLHS8L2Q7KCHk= ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=VVDH9WLs; spf=pass (imf11.hostedemail.com: domain of harry@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=harry@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1790263139; b=szbdRVLo9IFn9Qz2PbR5SBzeoB09nvs6j0/ErJa6vsWYD9xiIHduRSE3o0uRvvq5TgciIS WofNDpLtEkZtFT43HXi8udbJiUVQD4gE1FrigN79/L/r+tG9d68Q3IUgrFwXoAWUo1jQyy wCFm9S7XiRu79hbmTOqjbJWyv7eHEF4= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id D7256601DE; Thu, 24 Sep 2026 15:18:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1E6A61F000FF; Thu, 24 Sep 2026 15:18:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790263138; bh=r7s1CAgd45i1qVFJKno+reNnGoGUQMAT+I7uYiP/nks=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=VVDH9WLsvrmzpUg4Z+hLDHBG/pO4qlIBnTIodD5pt0BF9Re7iMX6ULoPqbHSz2RnM mymMnw1a5pmRQCiKHNjX4xaFkJd3E2HmVEGs+O7u5jfWVN5bmkH6nlOUe7THYjtE/f mL9o7Tj6iKdrgU8ZuOjyGB03amWLl/t1FrPbO9ve033yVQ+VQR2hizSLCNpgOzVIWT 6XnXVTerX2Y6rVe8Mk+UHq65CpLKmamkWuT4mkfE3jZlWwLjl051pbc+nuoNQpiPAh +Z2Nny5WtQQtwJzs7+VmPoQhFBBLhVHeoXzW8TFatOOXvBDWsF+IG4mzjumIzBkQ0I foBvXytVcx/3g== Date: Thu, 24 Sep 2026 16:18:56 +0100 From: Harry Yoo To: "Vlastimil Babka (SUSE)" Cc: Hao Li , Christoph Lameter , David Rientjes , Roman Gushchin , Geert Uytterhoeven , Conor Dooley , Damien Le Moal , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH RFC 0/8] replace CONFIG_SLUB_TINY with a slab_tiny boot parameter Message-ID: References: <20260923-slub_tiny_rework-v1-0-a0e66d536eb5@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260923-slub_tiny_rework-v1-0-a0e66d536eb5@kernel.org> X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 68EA540011 X-Stat-Signature: qeqrxak8fhgahzm43zgfxo9x54u9afnf X-HE-Tag: 1790263139-276877 X-HE-Meta: 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 FmJ/nCRl 6aHgNFpnram6b/Ltk0aHYlidXruST6GioNf+Tx/2h8hUqNJQUgciYvy1udZe65rhv9oZNVhdQEsVb4fydGeo3ckTRMN7LKozmuo5ObKJZAuI+2oT/zfais9SJAJHGCuDGnn4ESqgr2bwuIzA2zufe1wX4FunN/I9xd/MdlhHah5uJht+90rZJpUEOKKdDr3EQcbRFlPNMVH5OQ/TerNBswHDD6KZOtFz9psM2M0569noR0vA1q/Xidw3Yegy6zTHc6gZfqQOpz0wBHpvst5nxKkdIL2B2wOzvZwG+xSHETcd18QsA2hrC9NZyadAyvUgDIHBgL54n8+NZ28Y23QDFsKnxJA== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Sep 23, 2026 at 05:45:05PM +0200, Vlastimil Babka (SUSE) wrote: > To sum up, after this series: > > - CONFIG_SLUB_TINY is a deprecated option that has no interaction with > other options and only controls the default behavior. > > - New slab_tiny boot parameter controls the functionality (and can > override CONFIG_SLUB_TINY in both directions). > > - slab_debug=N can effectively achieve most of slab_tiny and on a > per-cache basic Allowing "slab_tiny=0" doesn't make much sense given that CONFIG_SLUB_TINY is deprecated anyway. I was assuming specifying "slab_tiny" would enable it and not specifying it would disable it unless CONFIG_SLUB_TINY is set. Also it's bit confusing to have multiple ways to achieve the same thing. Is there a reason why we can't interpret "slab_debug=N" as "slab_tiny_enabled = 1" internally and drop "slab_tiny" boot parameter? > - the implementation is simpler with many ifdefs removed > > [1] https://lore.kernel.org/all/CAHk-=wh-k04MsoEC0SGKff2Snm6bBF_e+0pHOKwaWv4umZ_SnQ@mail.gmail.com/ > > Signed-off-by: Vlastimil Babka (SUSE) > --- > Vlastimil Babka (SUSE) (8): > mm, slab: refactor slab_min/max_order handling > mm, slab: introduce slab_debug=N > mm, slab: rework KMALLOC_RECLAIM handling of SLUB_TINY > mm, slab: make SLUB_TINY handling dynamic for sizing decisions > mm, slab: convert CONFIG_SLUB_TINY checks to kmem_cache_debug() > mm, slab: remove remaining compile-time checks for CONFIG_SLUB_TINY > mm, slab: add slab_tiny boot param > mm, slab: deprecate CONFIG_SLUB_TINY and reduce its Kconfig effects > > Documentation/admin-guide/kernel-parameters.txt | 4 + > Documentation/admin-guide/mm/slab.rst | 18 ++- > include/linux/slab.h | 17 +-- > lib/Kconfig.kasan | 2 +- > mm/Kconfig | 16 ++- > mm/Kconfig.debug | 2 +- > mm/slab.h | 32 +++-- > mm/slab_common.c | 12 +- > mm/slub.c | 149 +++++++++++------------- > 9 files changed, 120 insertions(+), 132 deletions(-) > --- > base-commit: b4218126d498275444f315b0ed4cef6add6beabc > change-id: 20260911-slub_tiny_rework-8f2634dd17a7 > -- Cheers, Harry / Hyeonggon