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 259F13E1CE4; Wed, 1 Apr 2026 11:15:11 +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=1775042112; cv=none; b=Qobei/Q5PCdWaDcYd1buxCEtv/nBkvDVseprfxCSBSidmlRAGtFGVw9z/hUsFjWOMZDl6tmEGCZBUzHkLz+UszoupNZmZhDUJbV+H54LySnnEISnJ5mrWfZljNm8X8OQhjS12wLhY5CYbibL8ANUwLciRpF91sAfUJslijI9JSo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775042112; c=relaxed/simple; bh=dewT5thds98VTAImtEDNC0EfFTjUiz4qEvaiq2jKju4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=GW24lq3TPqHFYlT76CQHEC+5g2vdcejx5JgOZxISFSjDy5aO557UGHMMJSv1+zxZCTBhOB1D7rMg5RZMgcqk99sPkM2zq7f9KV4K3xs2HB9kMmSu+EBmXeqOqlWCRLZ0ipv1ga0TQq44sDkRNRMuPGb7o7yUMssz3S3H1OZLSRg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=K32yyvLf; 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="K32yyvLf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 93246C4CEF7; Wed, 1 Apr 2026 11:15:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775042111; bh=dewT5thds98VTAImtEDNC0EfFTjUiz4qEvaiq2jKju4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=K32yyvLfMjplva3EkWRS5sBRxaNW5h2A8wKlmF06k1twv/MTgVWjsJ2N6yJsDwD1a n7q5yhqJY+3pjT3mB2tlgJkWYrzk2VOIKX4Q7RrzFCCNHmFEMM8uCyvKjmjjDS+cGi NDlCoGWWo+vsO4zkGxbNjF5zPDkMW9zqBpwMx+JvyYOH9IOVa0pxnygel68fOHRVJ8 7BJV3MuB1GZ5vcBs7XjJibMa8uJPrd4YGaHF/Uhwcht5rMTomukjzwWoNnzERVvWyB KpxZZlQN9veszefrADFZNEA1ZF2sBYwbiJQEZxfnfj4IKu7ZUSiHRR3rq+y70noYel 8+OWFV/nITe4w== Date: Wed, 1 Apr 2026 12:15:04 +0100 From: "Lorenzo Stoakes (Oracle)" To: "Vlastimil Babka (SUSE)" Cc: Andrew Morton , Andrey Ryabinin , David Hildenbrand , 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: <20260401-b4-are-you-serious-v1-1-dcacda70647d@kernel.org> On Wed, Apr 01, 2026 at 12:59:29PM +0200, 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. > > - 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. > > - 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. Honestly you're making me look bad because mine is so 'positive' (I SWEAR IT IS TEST CODE AND COMMENTS) so this turns me against this patch... > > 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) ...but because you're removing clearly useless and superceded debug code (I mean hello, we have people using openclaw to automate all this unnecessary kernel dev stuff): Reviewed-by: claude-opus-4-6[1m] Assisted-by: Lorenzo Stokes (as per the register) Cheers, Claude