From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from outpost1.zedat.fu-berlin.de (outpost1.zedat.fu-berlin.de [130.133.4.66]) (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 569021CD2D; Thu, 2 May 2024 05:11:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=130.133.4.66 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714626719; cv=none; b=XaZesm2qkkRa78wXaZIyKGpHuAUlnqNv8LXLKmdODks+lk7RbXnrHRFcZJB+P3QimbGg+P2RPUsTa4sIEIe7ySQcBbsvkquC0sbvz1b6UJ/Umw0M//U4aUTH1i3UQdkdOVKrWYaQTigoUI31h/hPJ2bXPudlrejNpAA0VumNpjc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714626719; c=relaxed/simple; bh=O585nGdzNnTnC6USi0DOSwyhOSgyO5m/b1EV7zBQIxI=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=FixHFm8V6dB+xonPE8poE2cqUeSEsgefKlCZhkueHx7PhQurHwUT5Pb1oJKmgO/uznnugjrNQlvc5/CH4PGjZZqW1UYcfBg1MpDbEUxbpKGo4XxiksvIlYJC6ZnsITSUMMpiW2RQQDpMu/5135kAtZExx0UBOhVB1YMZAMBym4I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=physik.fu-berlin.de; spf=pass smtp.mailfrom=zedat.fu-berlin.de; dkim=pass (2048-bit key) header.d=fu-berlin.de header.i=@fu-berlin.de header.b=PrgAVRaa; arc=none smtp.client-ip=130.133.4.66 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) header.d=fu-berlin.de header.i=@fu-berlin.de header.b="PrgAVRaa" 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:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=utnjLft+cCCmNqwYGOcYhyYisPt1R0D1THzGmrMh7Z0=; t=1714626717; x=1715231517; b=PrgAVRaaP2LlsXY+G0bEogYKs6l2+YKY2oWZCUHbOpFhpvR2SYEz0cxBdBGm2ohLx5Nyp7Uo6eE E3X2/ygHHDw95bf2xHnxrpo1wKOf083hgfEQmPdRGwM/rAv7lOfw4f4acH805p05GMtv2FziuJN8g bbxehGC3ymyvzjFfGNYDFjlNH24pbReLxECxOh/HA46Ebz8E3y6uqrg59h/ZT09BOGsyFbF27SMh0 9uxHRr+C7r/T9tfiLtluButoeStTLF1vaWBPcIVjhZ4Pa2cdchIJZqSek6u/7SCxdNPTe4nLOMM// ZmOT7MVkzxuYf4zUZCfNFkYcARzVgCr1jPHw==; Received: from inpost2.zedat.fu-berlin.de ([130.133.4.69]) by outpost.zedat.fu-berlin.de (Exim 4.97) with esmtps (TLS1.3) tls TLS_AES_256_GCM_SHA384 (envelope-from ) id 1s2Oja-00000003yrB-0LCb; Thu, 02 May 2024 07:11:54 +0200 Received: from p57bd90e8.dip0.t-ipconnect.de ([87.189.144.232] helo=[192.168.178.20]) by inpost2.zedat.fu-berlin.de (Exim 4.97) with esmtpsa (TLS1.3) tls TLS_AES_256_GCM_SHA384 (envelope-from ) id 1s2OjZ-00000003JKb-3Ubj; Thu, 02 May 2024 07:11:53 +0200 Message-ID: <6f7743601fe7bd50c2855a8fd1ed8f766ef03cac.camel@physik.fu-berlin.de> Subject: Re: [PATCH v2 cmpxchg 12/13] sh: Emulate one-byte cmpxchg From: John Paul Adrian Glaubitz To: paulmck@kernel.org Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, elver@google.com, akpm@linux-foundation.org, tglx@linutronix.de, peterz@infradead.org, dianders@chromium.org, pmladek@suse.com, arnd@arndb.de, torvalds@linux-foundation.org, kernel-team@meta.com, Andi Shyti , Palmer Dabbelt , Masami Hiramatsu , linux-sh@vger.kernel.org Date: Thu, 02 May 2024 07:11:52 +0200 In-Reply-To: References: <20240501230130.1111603-12-paulmck@kernel.org> <1376850f47279e3a3f4f40e3de2784ae3ac30414.camel@physik.fu-berlin.de> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.52.0 Precedence: bulk X-Mailing-List: linux-sh@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Original-Sender: glaubitz@physik.fu-berlin.de X-ZEDAT-Hint: PO On Wed, 2024-05-01 at 22:06 -0700, Paul E. McKenney wrote: > > Does cmpxchg_emu_u8() have any advantages over the native xchg_u8()? >=20 > That would be 8-bit xchg() rather than 8-byte cmpxchg(), correct? Indeed. I realized this after sending my reply. > Or am I missing something subtle here that makes sh also support one-byte > (8-bit) cmpxchg()? Is there an explanation available that explains the rationale behind the series, so I can learn more about it? Also, I am opposed to removing Alpha entirely as it's still being actively maintained in Debian and Gentoo and works well. Adrian --=20 .''`. John Paul Adrian Glaubitz : :' : Debian Developer `. `' Physicist `- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913