From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E69D83EC2CB; Wed, 1 Apr 2026 11:19:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775042357; cv=none; b=ioM5r9VAjx5YDUr0K0FTtBgIJ5q48F10po8QNYyJ1g2F6uKKOYosewbVppYqJ1x9IWK8icCuc8sYHzArf4VFWC0lt5/fgei7xUnbMKz89ZNMnNG/zo2FB2o3GM94MMXHb7VS0drvswii8D9f6Tt4ILT0CSDNgYvo8XvihwqDACk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775042357; c=relaxed/simple; bh=xpFWMh9MkdSBc1hJn+/AhQ/w65T3zgOUU+VStizxE4I=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=aW/bAAQ0fyJIMS21Fg510bGOz8ydlXUywQUr3A9QWXoKw4DnY+VG8BHsQZhPR/0wHP6dICeH/uTblT9xqs5O6nRAq9QWTSa5LowH3VwGOwDKlNNCRqcUxmgSWgeEiSU3u7FEEdtwufWl3unKnR+BtkuHmXiZhsZarj7HrLI/hBE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=p3T1INlz; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="p3T1INlz" 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> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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