From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=130.133.4.66 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792573988; b=vhaHHAyh6e3wRK1HE3CpRCzlAqxg6Zw7S9C4CLP0jnI+5aVJLRFrvlNeF5A2S0NVAkeQ IfW/Jxp6TbfS2l895UMDCvH8ROdcP/T8dLzbqJxG3gkoyOdrtiYGIumecdYRptZsyoaAf pq27CNQfJYEUIjRTn1rsEcW9OOas0ZJ9EGklBmC4h/d4MFO+hRunkfqiIiMZ1zoIyDhg8 RqIiCg3Z92NTTEUQrtOJvWxOL3sKuZMcroPu4igf6PaZ6744gnvy9h9ahH57JQT+PMFN/ 90fiff/P6iydTVJCdmwSxa1gPktpe3oKPaRYcDNt3r7V35dt9aPOD4A2cbhKqtlZcNw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792573988; h=DMARC-Filter:DKIM-Signature:Received:Received:Message-ID:Subject: From:To:Cc:Date:In-Reply-To:References:Content-Type: Content-Transfer-Encoding:User-Agent:MIME-Version:X-Original-Sender: X-Originating-IP:X-ZEDAT-Hint; bh=R4jqZPX5alIiyxxB/iHbYUMvL4Tmy64E74qo6XrsUQk=; b=3GLMtIepCGBJoS8ba7HKDaWhcY8hsHhlGiHLkq7+boaCEZDIersuG1ubD0lC6tznZSmh hIihb4AMaEs7gdk5o3QTWp0VWvjExswj+pDeNFuT5ldf2yJmj2PDSDTS1VivtFt29kg0d N/IaHwv8fxosw5QzsMq7OxEq1L1CflQ7Bb+hGbrvyvL+qeHrh0rED7g6aoPjU1r9a8Vtt Q/YedudMSfjDTH7bXePVLMUM9zH0vA4sniU60woJ96P9PKPqZIiuI+S07RSdDF8a0kTsr 6zqUCgBFeMQWaB7flrfowx5Fgv84PUdKhAn68FAPdWQnxdWexUyKgHm//r9i7WGluyg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=physik.fu-berlin.de; spf=pass smtp.mailfrom=zedat.fu-berlin.de; dkim=pass header.d=fu-berlin.de header.i=@fu-berlin.de header.a=rsa-sha256 header.s=fub01 header.b=UlnEftD3; arc=none smtp.remote-ip=130.133.4.66 Received: from outpost1.zedat.fu-berlin.de (outpost1.zedat.fu-berlin.de [130.133.4.66]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9DAC9606A31A for ; Wed, 21 Oct 2026 09:13:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 9DAC9606A31A Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=physik.fu-berlin.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zedat.fu-berlin.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=fu-berlin.de header.i=@fu-berlin.de header.a=rsa-sha256 header.s=fub01 header.b=UlnEftD3 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=fu-berlin.de; s=fub01; h=MIME-Version:Content-Transfer-Encoding: Content-Type:References:In-Reply-To:Date:Cc:To:From:Subject:Message-ID:From: Reply-To:Subject:Date:Message-ID:To:Cc:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:In-Reply-To: References; bh=R4jqZPX5alIiyxxB/iHbYUMvL4Tmy64E74qo6XrsUQk=; t=1792573987; x=1793178787; b=UlnEftD35DQkGT9rVfeY343RPkWbFjxY5p1GPbr9Q28mwIzmEypv4KykTUmNf szkhXTf9cmqgzDBdal+8b1W7futtEYq7oPu5wAvFMb+srOqzchuviYoSMwXpeIeQA5CO76iKM+EIz 3lElolzaBEK75kD7eMNMaavvknVruiGRJbhY86moG5/EpeYnlLQSPbbo2MEdncImxrvZEc/gknDlb xSrwZWe5Y++X+7WvankqiKqXJrc2JPbdY19PkROdzpdp1STfPSKeCdopJ/xVWYZGUCPztu59udVzY cnhIlxL0kZo+JNbbT+oWSewRtz+OxHjrnAYj3XNimCQ+E0eQWA==; Received: from inpost2.zedat.fu-berlin.de ([130.133.4.69]) by outpost.zedat.fu-berlin.de (Exim 4.100) with esmtps (TLS1.3) tls TLS_AES_256_GCM_SHA384 (envelope-from ) id 1xJSNc-00000001e89-3Eu9; Wed, 21 Oct 2026 11:13:04 +0200 Received: from p5b13a90a.dip0.t-ipconnect.de ([91.19.169.10] helo=[192.168.178.61]) by inpost2.zedat.fu-berlin.de (Exim 4.100) with esmtpsa (TLS1.3) tls TLS_AES_256_GCM_SHA384 (envelope-from ) id 1xJSNc-00000003MTl-1uQM; Wed, 21 Oct 2026 11:13:04 +0200 Message-ID: Subject: Re: [GIT PULL] Add two-byte cmpxchg emulation function for v7.4 From: John Paul Adrian Glaubitz To: paulmck@kernel.org Cc: torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, kernel-team@meta.com, Bradley Morgan , Arnd Bergmann , phoronix@phoronix.com Date: Wed, 21 Oct 2026 11:13:03 +0200 In-Reply-To: <851e3a8d-dd0d-49cb-8672-5cebc03d910b@paulmck-laptop> References: <2f65337241e230cd26c130bc3183ad230c7c40e4.camel@physik.fu-berlin.de> <851e3a8d-dd0d-49cb-8672-5cebc03d910b@paulmck-laptop> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.60.2 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 X-Original-Sender: glaubitz@physik.fu-berlin.de X-ZEDAT-Hint: PO Hello Paul, On Tue, 2026-10-20 at 12:14 -0700, Paul E. McKenney wrote: > On Tue, Oct 20, 2026 at 08:48:32PM +0200, John Paul Adrian Glaubitz wrote= : > > Hi Paul, > >=20 > > On Fri, 2026-10-16 at 20:51 -0700, Paul E. McKenney wrote: > > > However, it sadly does not permit easy implementation of all algorith= ms > > > needing on two-byte atomic operations because there are some systems = still > > > supported by Linux that do not have native two-byte store instruction= s. > > > There is reason to believe that these systems will soon no longer be > > > supported by Linux. > >=20 > > Since this paragraph has produced a headline today [1], would you mind > > clarifying what you meant here? What architectures are you talking abou= t? >=20 > The important word in the second paragraph quoted by the article is > "systems", which is not "architectures". To its credit, the article > keeps this straight, but not so much the comments. >=20 > And here is Arnd Bergmann's patch that started this: >=20 > https://lore.kernel.org/all/20260908152808.3928630-4-arnd@kernel.org/ >=20 > The system Arnd calls out is the Acorn Risc PC, which is one member of th= e > Arm family. So not an entire architecture, but rather just a particular > implementation of an architecture, and an old one at that. Not only > that, but if I remember correctly, Arnd got considerable pushback, > so I am not sure that his support-removal patch is going in just yet, > as in I do not yet see it in -next. >=20 > Please feel free to add this as a comment to the article, as the site > is not permitting me to do so. I have added their feedback email on > CC in case that helps, and in the hope that my doing so does not unduly > annoy them. Thanks a lot for the clarification, much appreciated! Relieved, Adrian --=20 .''`. John Paul Adrian Glaubitz : :' : Debian Developer `. `' Physicist `- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913