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=-9.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 E0A64C4338F for ; Fri, 30 Jul 2021 13:51:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C321760EB5 for ; Fri, 30 Jul 2021 13:51:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239031AbhG3NvH (ORCPT ); Fri, 30 Jul 2021 09:51:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58774 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231137AbhG3NvG (ORCPT ); Fri, 30 Jul 2021 09:51:06 -0400 Received: from mail-pl1-x634.google.com (mail-pl1-x634.google.com [IPv6:2607:f8b0:4864:20::634]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CC2A6C06175F for ; Fri, 30 Jul 2021 06:51:00 -0700 (PDT) Received: by mail-pl1-x634.google.com with SMTP id a20so11228336plm.0 for ; Fri, 30 Jul 2021 06:51:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=to:from:subject:message-id:date:user-agent:mime-version :content-language:content-transfer-encoding; bh=Fg+J3oW692Mh3cj6C7vQfzGK/Q/IMQA26Bq+Duy+a4w=; b=VmcZG1GRWJrPQtzy+TCHvuVNPKTGa+BsqIntwj6ttKUN/bSbXgL70/Xodxa74Ma4p0 rwxlQt0RRyaJZejJxeJi8BBKEbUuPiOrHslCY+HUINYp1SJ1iolaJkON0f5eGEMyYsC/ 9Le3jMLov9yMGz2bDatl71kjesThyRzy7wewQhjnsafaTOnUnYfbwd438/L0Nt4KgTZW 4qC6zQI1wNFf7sWKkZnojJgg6pzBK8eaPLVoFKzn7plTdUfqYk/mAYEF6HOxS0z93kjj AFO9Vm2OULZA9T1QhehMkU7M6O8/p3OGEGYzj+dKxhpXYdHjwzpHkLvzGv3XAxEKXoR7 cyPQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:to:from:subject:message-id:date:user-agent :mime-version:content-language:content-transfer-encoding; bh=Fg+J3oW692Mh3cj6C7vQfzGK/Q/IMQA26Bq+Duy+a4w=; b=j3lFpHmMjcmH63eWR9YRdu8y3vSJ7SJkogtdmYRj/jIumYOuxn4c56uKiRa5Q+hAig Gyel8OuQ6P3twpLJ3KAtJWOeIgmgZM+yNYNOCQYVDKlnCIaBSl8Dk31JAWz8fgeQ9GjV j2zfQp/DUaYGqZNZ6OGv/5me9g/eHe4bGxVoHnw2UabsFqoSjmdLqt+hfjvInggQd4xm q/AiR9H0wXkYbCfTEIbn/CGD0+aUfHHC3gjI1+VxUuKnDNl77hT+2IOqLrP1YEJ2GkW/ CuMoBf63Qh17vQXg1dF9AQ3VHYs7OBolRdVy7I4c+ETNxT8hGZclBlgHzYi/8+yU33+v DUMQ== X-Gm-Message-State: AOAM53236jzujDhllr5t1Kqk3qlRBW3usvSf+zneM15aXaLEXbuEjlao nbB0Yy4Iw/YGRzOkwtPGph+HaE8sZKxL6A== X-Google-Smtp-Source: ABdhPJw0kB2BBs33d+TllZbOUWcOrwfM9KEon9kLTtG4TWSRM1Sy3r6nfGeaiiH6RDmPosurY61KYg== X-Received: by 2002:a17:90a:c003:: with SMTP id p3mr3212973pjt.14.1627653059822; Fri, 30 Jul 2021 06:50:59 -0700 (PDT) Received: from [192.168.1.153] (M106072041033.v4.enabler.ne.jp. [106.72.41.33]) by smtp.gmail.com with ESMTPSA id n5sm2534471pfv.29.2021.07.30.06.50.56 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 30 Jul 2021 06:50:59 -0700 (PDT) To: Paul Walmsley , Palmer Dabbelt , Guenter Roeck , Geert Uytterhoeven , Qiu Wenbo , Albert Ou , Akira Tsukamoto , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org From: Akira Tsukamoto Subject: [PATCH 0/1] __asm_copy_to-from_user: Reduce more byte_copy Message-ID: <65f08f01-d4ce-75c2-030b-f8759003e061@gmail.com> Date: Fri, 30 Jul 2021 22:50:52 +0900 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Adding none unrolling word_copy, which is used if the size is smaller than 9*SZREG. This patch is based on Palmer's past comment. > My guess is that some workloads will want some smaller unrolling factors, It will reduce the number of slow byte_copy being used when the size is small. Have tested on qemu rv32, qemu rv64 and beaglev beta board. In the future, I am planning to convert uaccess.S to inline assembly in .c file. Then it will be easier to optimize on both in-order core and out-of-order core with #ifdef macro in c. Akira Tsukamoto (1): riscv: __asm_copy_to-from_user: Improve using word copy if size < 9*SZREG arch/riscv/lib/uaccess.S | 46 ++++++++++++++++++++++++++++++++++++---- 1 file changed, 42 insertions(+), 4 deletions(-) -- 2.17.1