From patchwork Wed Oct 30 15:53:08 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Walmsley X-Patchwork-Id: 3115391 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id D58BDBF924 for ; Wed, 30 Oct 2013 15:53:46 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id C3597203E1 for ; Wed, 30 Oct 2013 15:53:45 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E3EFA203E9 for ; Wed, 30 Oct 2013 15:53:40 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VbY5Q-0006L2-St; Wed, 30 Oct 2013 15:53:37 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VbY5O-0001zm-DL; Wed, 30 Oct 2013 15:53:34 +0000 Received: from hqemgate16.nvidia.com ([216.228.121.65]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VbY5L-0001yQ-Dh for linux-arm-kernel@lists.infradead.org; Wed, 30 Oct 2013 15:53:32 +0000 Received: from hqnvupgp07.nvidia.com (Not Verified[216.228.121.13]) by hqemgate16.nvidia.com id ; Wed, 30 Oct 2013 08:53:22 -0700 Received: from hqemhub01.nvidia.com ([172.20.12.94]) by hqnvupgp07.nvidia.com (PGP Universal service); Wed, 30 Oct 2013 08:52:34 -0700 X-PGP-Universal: processed; by hqnvupgp07.nvidia.com on Wed, 30 Oct 2013 08:52:34 -0700 Received: from hqnvemgw01.nvidia.com (172.20.150.20) by hqemhub01.nvidia.com (172.20.150.30) with Microsoft SMTP Server id 8.3.327.1; Wed, 30 Oct 2013 08:53:08 -0700 Received: from sc-daphne.nvidia.com (Not Verified[172.20.232.60]) by hqnvemgw01.nvidia.com with MailMarshal (v7,1,2,5326) id ; Wed, 30 Oct 2013 08:53:08 -0700 Received: from tamien.nvidia.com (tamien.nvidia.com [172.17.186.57]) by sc-daphne.nvidia.com (8.13.8+Sun/8.8.8) with ESMTP id r9UFr8jc008329; Wed, 30 Oct 2013 08:53:08 -0700 (PDT) Date: Wed, 30 Oct 2013 08:53:08 -0700 From: Paul Walmsley X-X-Sender: pwalmsley@tamien To: Russell King - ARM Linux Subject: Re: [GIT PULL] prefetch support for 3.13 In-Reply-To: <20131030152553.GD16735@n2100.arm.linux.org.uk> Message-ID: References: <20131009171312.GJ8378@mudshark.cambridge.arm.com> <527124B3.9090305@nvidia.com> <20131030152553.GD16735@n2100.arm.linux.org.uk> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20131030_115331_542819_91154B16 X-CRM114-Status: GOOD ( 19.74 ) X-Spam-Score: -2.4 (--) Cc: Stephen Warren , Thierry Reding , Will Deacon , "linux-arm-kernel@lists.infradead.org" X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.7 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Hi Russell, On Wed, 30 Oct 2013, Russell King - ARM Linux wrote: > On Wed, Oct 30, 2013 at 08:24:35AM -0700, Paul Walmsley wrote: >> Hi Will et al., >> >> On 10/09/2013 10:13 AM, Will Deacon wrote: >>> Hi Russell, >>> >>> Please pull the following patches for 3.13. They add support for the pldw >>> instruction (prefetch with intent to modify) in ARMv7 SMP cores, which is >>> then used to gain a measurable performance boost for particular atomic >>> sequences. >> >> Looks like the pldw changes require binutils >= 2.21. Might be worth >> considering a patch to update Documentation/Changes? > > Not really - because that says "for all architectures the minimum > requirement is now 2.21 or later" and that's certainly not the case. > > It's only ARMv7 which requires this. Would you consider something like the following? - Paul From: Paul Walmsley Date: Wed, 30 Oct 2013 08:51:26 -0700 Subject: [PATCH] Documentation/Changes: update binutils version requirement for ARMv7 builds ARMv7 builds now make use of the pldw opcode and the ".arch_extension mp" pragma. These aren't supported in binutils prior to 2.21. So, update Documentation/Changes accordingly. Signed-off-by: Paul Walmsley Cc: Will Deacon Cc: Russell King Cc: Stephen Warren Cc: Thierry Reding Acked-by: Russell King --- Documentation/Changes | 3 +++ 1 file changed, 3 insertions(+) diff --git a/Documentation/Changes b/Documentation/Changes index b175808..97fcbdf 100644 --- a/Documentation/Changes +++ b/Documentation/Changes @@ -67,6 +67,9 @@ assembling the 16-bit boot code, removing the need for as86 to compile your kernel. This change does, however, mean that you need a recent release of binutils. +ARMv7 builds require binutils 2.21 or later due to the use of the pldw +opcode and ".arch_extension mp". + Perl ----