From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 128CAC433FF for ; Mon, 12 Aug 2019 19:49:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CE00320673 for ; Mon, 12 Aug 2019 19:49:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=bluespec-com.20150623.gappssmtp.com header.i=@bluespec-com.20150623.gappssmtp.com header.b="jltM4Ar/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726975AbfHLTtJ (ORCPT ); Mon, 12 Aug 2019 15:49:09 -0400 Received: from mail-qt1-f193.google.com ([209.85.160.193]:36979 "EHLO mail-qt1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726812AbfHLTtJ (ORCPT ); Mon, 12 Aug 2019 15:49:09 -0400 Received: by mail-qt1-f193.google.com with SMTP id y26so104103424qto.4 for ; Mon, 12 Aug 2019 12:49:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bluespec-com.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=UV8CKdboAmk/VxMPvqRcAfLPhy32LDZ4SxfI8+jq9eA=; b=jltM4Ar/lpuGu7lyFR8pJwgeA74SyhzojO+40mYneDCJsl94QUPrx70p61RHEz6xmu vxkRFSG8yB7Urm7pDINv5eITQYdhi20v2JKnVgLly8r+4TngIEXqgfyJWjjSMtT9mBQt gUCHl9Xmv24ePdraDYLmy1ht3MgFF7ACGEWY0cz6IJuxACbJ6YYWtRlW1EWgEI7xjhTQ YdjyYRXfgrXbypaFlvxwk/W2pesE3Uc5mymbJ0gXtvHWJZwSGwFXuIwJa6uYu+k9fRYM 4wacfQuGkmQNOA5D6T6KTCi+hPh1pS6fcmEI0l8+cpFJNfBoCux0WwPHe0DCajgkek9P Zrag== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=UV8CKdboAmk/VxMPvqRcAfLPhy32LDZ4SxfI8+jq9eA=; b=fNE43CCqJO3kJtAdyslyFUV+6gTnORtLWYanx++VgsuC4pqgYK1rHzDXE28PWxodKc R6SYkDWnyOt2l6nFmsCefr/1O9dRcoN+GSHe8IGWglh56ihe5meQl+l7U/cHzkOOsBMx CpAYaS5cGMkZa8X92GUuUMAB4MRQo7jlTIlSZ0q4b50B+13GRRJBuUuKq18diGcDYnbG Hsxb/IebLpBdE76OsSORP8bjIh94zxCgxU9ogq52nPg9QzmBdBejt287pr089W5e3pzk aiepEKo3BMWiuW0RhP/XAF/w0OhDZaGBlUo1rn7ggR6HtrENPqEMBLAcJaItp/AnazUS dRKA== X-Gm-Message-State: APjAAAUgmPhym7pJj57mWNswfORbq+QRlHmmQwtApMSF2+f/ogRQGI3d /vXWx1p+5xn1MUMPABNzwW6A X-Google-Smtp-Source: APXvYqwt1wY0kFXUf2SJJ0SNo1VLt4PBkuZhW7TlkhaF569W0Da1qsUMXXhslmo12N/U1uTW9SVUGg== X-Received: by 2002:ac8:30f3:: with SMTP id w48mr29811591qta.216.1565639348315; Mon, 12 Aug 2019 12:49:08 -0700 (PDT) Received: from [10.7.11.6] ([194.59.251.156]) by smtp.gmail.com with ESMTPSA id k21sm7850588qki.50.2019.08.12.12.49.06 (version=TLS1_3 cipher=AEAD-AES128-GCM-SHA256 bits=128/128); Mon, 12 Aug 2019 12:49:07 -0700 (PDT) Subject: Re: [PATCH] riscv: kbuild: drop CONFIG_RISCV_ISA_C To: Christoph Hellwig , Charles Papon Cc: Atish Patra , linux-riscv , Bin Meng , linux-kernel , Paul Walmsley References: <20190812150348.GH26897@infradead.org> From: Darius Rad Message-ID: <5a931461-c6a8-6d2d-4f73-103a10b26f0e@bluespec.com> Date: Mon, 12 Aug 2019 15:49:06 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190812150348.GH26897@infradead.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/12/19 11:03 AM, Christoph Hellwig wrote: > On Thu, Aug 08, 2019 at 02:18:53PM +0200, Charles Papon wrote: >> Please do not drop it. >> >> Compressed instruction extension has some specific overhead in small >> RISC-V FPGA softcore, especialy in the ones which can't implement the >> register file read in a asynchronous manner because of the FPGA >> technology. >> What are reasons to enforce RVC ? > > Because it it the unix platform baseline as stated in the patch. > The same argument could be made for an FPU or MMU, yet there are options to disable those.