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 4E27ED35162 for ; Wed, 1 Apr 2026 11:19:20 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B5C5E6B0089; Wed, 1 Apr 2026 07:19:19 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AE6636B008A; Wed, 1 Apr 2026 07:19:19 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9AE056B0092; Wed, 1 Apr 2026 07:19:19 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 8674B6B0089 for ; Wed, 1 Apr 2026 07:19:19 -0400 (EDT) Received: from smtpin18.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 2268E160847 for ; Wed, 1 Apr 2026 11:19:19 +0000 (UTC) X-FDA: 84609740838.18.C0FA47E Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf21.hostedemail.com (Postfix) with ESMTP id 79DF91C000F for ; Wed, 1 Apr 2026 11:19:17 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=p3T1INlz; spf=pass (imf21.hostedemail.com: domain of ljs@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=ljs@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=1775042357; 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=j4rIOdL4hDW/Y6phoK2Qqh4ggQ5XNBvZZDrtqgZzdUU=; b=PPygbsm/61rdQZK9aqmdWqsnL2ZWLR+Zc62YACgzDoVTBPEIBRIfOwXeozAmdzLb7IhYXh RKf5BAV6KLIj8iAQwYVB20OKIEiv+jAlIKr4hkaUDGCs2a93SMk8RT/KQ/x6M+bmD880/h wCW/zQMujV9GPiapF6Dt0NKGNJTT8mU= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1775042357; a=rsa-sha256; cv=none; b=j5KrpYS+UFixjrIELRF+1lesxH2DNM92ZJYMgHG59Yj3XDjxNvXsQFKXht7GCYBX4g1sh+ Vn+fiMZ+sNU4dbLShZoy9JtXaosSCBUZyqeOkuwQB+NSsKoIynaY2RCi+kFURIb782TuMD 8PMYvUAHjIWL9IBQfVMurZLay5+eM78= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=p3T1INlz; spf=pass (imf21.hostedemail.com: domain of ljs@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=ljs@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id DDBE860131; Wed, 1 Apr 2026 11:19:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 71C6BC4CEF7; Wed, 1 Apr 2026 11:19:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775042356; bh=xpFWMh9MkdSBc1hJn+/AhQ/w65T3zgOUU+VStizxE4I=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=p3T1INlz224JnvHd+iI/XTnAO57Xnl3aK9ePNoq/6qIJSX5mgLV+QHeUTpHeQXZhS AOKIshDblweICaHv7+3y7gpoNJnSgXUUyvsP0J3BJQ5MHIAZnntCiKjPetRiIIu2s0 kP+fEhUtZMfMWv0qy/qUs5yjQkZpOKcP49EYUHiAq2HFx3AYfQgNDwa7Gdhg9HJMIj BHE4QbHE805rQ7ISCK28qG/Dn83fdR3bU8IHdZVCrNdXtAKqLu+kNIaX3LifW6wK0n /HZOJGHGkpF7y8srBH7x6egrSN350zRfrcNr8Kj9Nkb3EMxdkzFtsJ8eibqndNsMwA FkLH/NxvGiYew== Date: Wed, 1 Apr 2026 12:19:09 +0100 From: "Lorenzo Stoakes (Oracle)" To: "David Hildenbrand (Arm)" Cc: "Vlastimil Babka (SUSE)" , Andrew Morton , Andrey Ryabinin , Johannes Weiner , Michal Hocko , Roman Gushchin , Shakeel Butt , Harry Yoo , Alexander Potapenko , Andrey Konovalov , Dmitry Vyukov , Vincenzo Frascino , "Liam R. Howlett" , Mike Rapoport , Suren Baghdasaryan , Muchun Song , Hao Li , Christoph Lameter , David Rientjes , Pedro Falcato , Jann Horn , Matthew Wilcox , Petr Tesarik , linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, cgroups@vger.kernel.org Subject: Re: [PATCH] slab: remove the SLUB_DEBUG functionality and config option Message-ID: References: <20260401-b4-are-you-serious-v1-1-dcacda70647d@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: 79DF91C000F X-Stat-Signature: qunt535sps83am5foinegh7m8t94uzjp X-Rspam-User: X-Rspamd-Server: rspam07 X-HE-Tag: 1775042357-817425 X-HE-Meta: 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 J9UJzmG2 HoOdsMmWp4YW38T0C6gdoZVajt0A60I5dyLqC8zc+GdB0jFM3hKAGVGE70HasOyqmKZ4RQiMI1BRh4zS2wHU7F2hObeE7Mmt2u47Fu4RbCdaCVQL/5QabJp3VvgNaxUs1eUhsEoXfqDv565+f4q3PiWviCzhGgqNpbI38hWaYGdKoVxlwmmyeT9FcljxYbo5Lrt0dJI2bfD+1AGPuLESKbRnHnJpssD/m6U36a8KJeEf6pjEBwWtJqjKH+VrWqR2qHXgOT4udi5g/u72yavukyiBT2Oxnm06SMr5Q8bNOTZ+yaLmkXShDdsjGEniW+IZVTkLhWrOdTvqrO5Y7A+5Sjo886mZRBTBxAwiR Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Apr 01, 2026 at 01:05:34PM +0200, David Hildenbrand (Arm) wrote: > On 4/1/26 12:59, Vlastimil Babka (SUSE) wrote: > > The boot-time enabled per-cache debugging has served us well in the > > past, but it's time for it to go, for the following reasons. > > > > - It's a debugging feature. However, thanks to the advent of LLM-based > > reviews, we are not adding bugs to the kernel anymore, so it's > > unnecessary now. > > Right, and probably LLM review would find many of bugs in the existing > SLUB_DEBUG code. > > > > > - KASAN is more powerful anyway for the classes of bugs that SLUB_DEBUG > > can catch. But I suspect KASAN is likely to be removed soon too, see > > above. > > Of course. > > > > > - SLAB never had no such dynamic debugging functionality. With the > > introduction of sheaves percpu caching, we have turned SLUB back into > > SLAB partially, so this just follows that direction. > > > > - It's removing ~2500 lines of code and I want to keep my overal > > diffstats negative. This adds a nice margin. > > Personal stats clearly matter more than anything else. > > > > > Since the slub kunit test depends on SLUB_DEBUG, remove it too. It's not > > a big loss, see the first point above. > > > > Singed-off-by: Vlastimil Babka (SUSE) > > --- > > Signed-off-by: Vlastimil Babka (SUSE) > > --- > > lib/Kconfig.debug | 12 - > > lib/Kconfig.kasan | 2 - > > lib/tests/Makefile | 1 - > > lib/tests/slub_kunit.c | 329 -------- > > mm/Kconfig.debug | 60 -- > > mm/dmapool.c | 4 - > > mm/memcontrol-v1.c | 17 - > > mm/mempool.c | 105 --- > > mm/slab.h | 34 - > > mm/slub.c | 2074 +----------------------------------------------- > > slab.h vs. slub.c is annoying. > > Can you just rename that to sheaf.c / sheaf.h now while at it? I'd prefer sheav.es.c, but naturally all comments in that file would need to be translated to Spanish. > > -- > Cheers, > > David Cheers, Lorenzo