From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 CD7F237F304; Mon, 27 Jul 2026 05:41:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785130887; cv=none; b=Iy6PREqXgvF2KghmEGGu2qRE85zevqWqtMZpx74QOHuHBq1FNEw+64gt8rbHYl7F2gL0xTqH/8hoDMaoyPENSfrvZ+v3GDFOkilRNnasMDpUIOtbFf27xrfyJxKufTeKx6cXfRxVOyKq9D6DC1Kb5hFFLu9sm3/ukiD5cubklyA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785130887; c=relaxed/simple; bh=KBGxVKBVcPUvP2K8Kq2m/WESxz8RXhfqZ6Mnq5IoEO4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=qgdtsDcDvcUMtM0DPaKpM3BayqBDg83R3ebSW9z8/v4Qf154TcvPqROsvj0f1NQhS38lUViPyLL6cm+FJ3GnSSd9Sk82/18dk8GLSVIZD+SWWm7DOUXj7YCoaEpxnV74gUo1RFVPwG0yrsmPG83NCn8uuNaZJyU83NR2ktqTcTM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=CckjAe+u; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="CckjAe+u" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3345C1F00A3A; Mon, 27 Jul 2026 05:41:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785130886; bh=KBGxVKBVcPUvP2K8Kq2m/WESxz8RXhfqZ6Mnq5IoEO4=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=CckjAe+u8aiFdiwdleeGwEQnEKVUjrWDcX6k3I3hMQkAvD/E6HfuB18CvzHDfuZzz idU7A9Z7y6qZNj9IWcFBzLD2rMv8kUbRNhhkgkKHcEjx1Bv52UG8RSIVwcTj3IfHPs zEe2fVv0Hv9fuoKUlUr5M8rQ8zqWioNndRBmaL/RQnqXQV06Q1g7MSka9/ljLUYB82 6qHZIVFNsJwpAaoRlPiNOFv96kUqkNo9w3aP5h0VcQvwxXka0wP6C0RE57Vd+Iw8Oj Iaqn5NMjKrSxKNEMxBGwTeyOqP1ct0PWxOxwTUrutpaLFo7cFpV/f8g89eogppZ209 nlbm5Wdef5Kdg== Message-ID: <89662cae-b3d9-4aa4-a7fa-cf5931781dbc@kernel.org> Date: Mon, 27 Jul 2026 14:41:20 +0900 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 09/13] mm/slab: change struct slabobj_ext to a union To: "Vlastimil Babka (SUSE)" , Hao Li Cc: Suren Baghdasaryan , Shakeel Butt , Alexander Potapenko , Marco Elver , Andrew Morton , Christoph Lameter , David Rientjes , Roman Gushchin , linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org References: <20260720-b4-objext_split-v2-0-2fa7c6f60dbe@kernel.org> <20260720-b4-objext_split-v2-9-2fa7c6f60dbe@kernel.org> <9b2dadb7-8e3d-4b9b-a870-969be9a7a432@kernel.org> Content-Language: en-US From: Harry Yoo In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="------------Mgwd0Ze9mOCZYycSnvRZAlba" This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --------------Mgwd0Ze9mOCZYycSnvRZAlba Content-Type: multipart/mixed; boundary="------------xEDZ3aIuuqtyEFJe6gHUB0km"; protected-headers="v1" From: Harry Yoo To: "Vlastimil Babka (SUSE)" , Hao Li Cc: Suren Baghdasaryan , Shakeel Butt , Alexander Potapenko , Marco Elver , Andrew Morton , Christoph Lameter , David Rientjes , Roman Gushchin , linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org Message-ID: <89662cae-b3d9-4aa4-a7fa-cf5931781dbc@kernel.org> Subject: Re: [PATCH v2 09/13] mm/slab: change struct slabobj_ext to a union References: <20260720-b4-objext_split-v2-0-2fa7c6f60dbe@kernel.org> <20260720-b4-objext_split-v2-9-2fa7c6f60dbe@kernel.org> <9b2dadb7-8e3d-4b9b-a870-969be9a7a432@kernel.org> In-Reply-To: --------------xEDZ3aIuuqtyEFJe6gHUB0km Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 7/25/26 12:42 AM, Vlastimil Babka (SUSE) wrote: > On 7/23/26 11:56, Hao Li wrote: >> On Thu, Jul 23, 2026 at 03:27:51PM +0900, Harry Yoo wrote: >>> >>> and drop OBJEXT_FLAG_UNUSED. >> >> Yes, this idea is insightful and I think it may need a standalone patc= h without >> blocking current patchset. >> >>> >>> ...not sure how much we care about this on 32bit though. >> >> Yeah, 32bit is a rare arch today :) >=20 > Agreed with you both. Let's deal with it later. Sounds reasonable. > Also AFAICS the memory was already wasted on 32bit prior this series wh= en > e.g. CONFIG_MEM_ALLOC_PROFILING was disabled, so there was just 4-byte = objcg > pointer in 8-byte aligned slabobj_ext, right? Right. --=20 Cheers, Harry / Hyeonggon --------------xEDZ3aIuuqtyEFJe6gHUB0km-- --------------Mgwd0Ze9mOCZYycSnvRZAlba Content-Type: application/pgp-signature; name="OpenPGP_signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="OpenPGP_signature.asc" -----BEGIN PGP SIGNATURE----- iHUEARYKAB0WIQQQ1ub6gR5ogjaKRmOGXBN6rc5S1gUCambvgAAKCRCGXBN6rc5S 1i+uAP4zMR6KAfExVASA33SIec4hOe1qPSAA+y6SvbztDbmuwwD+O9oxG/LJahjB u7CQFZJxg9HPyZTA9A2Q25sRF9mC3QA= =RYZd -----END PGP SIGNATURE----- --------------Mgwd0Ze9mOCZYycSnvRZAlba--