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[209.132.180.67]) by mx.google.com with ESMTP id j24si1406040otn.110.2020.01.23.09.20.20; Thu, 23 Jan 2020 09:20:33 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=zNRh2GsC; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729251AbgAWRQr (ORCPT + 99 others); Thu, 23 Jan 2020 12:16:47 -0500 Received: from mail.kernel.org ([198.145.29.99]:37780 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728731AbgAWRQr (ORCPT ); Thu, 23 Jan 2020 12:16:47 -0500 Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E7DE120704; Thu, 23 Jan 2020 17:16:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579799807; bh=caBzUH87lp4Mnc407nS8xaDKbecRpmkU11Lh6D8ZhtQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=zNRh2GsCZfIoZh4vccc1qvE+NoVJ8wQSpBQfnqOa4+8OlwkJZhKclmRqaog119FBv zLMeEWjpgKczZUNmIUDzTwfDe/ri/qOipH9vsM2UbV9eePmZWHfMv96M0DIWJUrJdZ eG9Bx4uNv7OmEajDz04SIDsYG/YS0LdLdevWoarI= Date: Thu, 23 Jan 2020 17:16:41 +0000 From: Will Deacon To: David Laight Cc: "linux-kernel@vger.kernel.org" , "linux-arch@vger.kernel.org" , "kernel-team@android.com" , Michael Ellerman , Peter Zijlstra , Linus Torvalds , Segher Boessenkool , Christian Borntraeger , Luc Van Oostenryck , Arnd Bergmann , Peter Oberparleiter , Masahiro Yamada , Nick Desaulniers Subject: Re: [PATCH v2 00/10] Rework READ_ONCE() to improve codegen Message-ID: <20200123171641.GC20126@willie-the-truck> References: <20200123153341.19947-1-will@kernel.org> <26ad7a8a975c4e06b44a3184d7c86e5f@AcuMS.aculab.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <26ad7a8a975c4e06b44a3184d7c86e5f@AcuMS.aculab.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 23, 2020 at 05:07:40PM +0000, David Laight wrote: > From: Will Deacon > > Sent: 23 January 2020 15:34 > ... > > * Only warn once at build-time if GCC prior to 4.8 is detected... > > > > * ... and then raise the minimum GCC version to 4.8, with an error for > > older versions of the compiler > > If the kernel compiled with gcc 4.7 is likely to be buggy, don't these > need to be in the other order? > > Otherwise you need to keep the old versions for use with the old > compilers. I think it depends how much we care about those older compilers. My series first moves it to "Good luck mate, you're on your own" and then follows up with a "Let me take that off you it's sharp". Will