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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 5831DC4361B for ; Mon, 14 Dec 2020 02:29:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1D44022240 for ; Mon, 14 Dec 2020 02:29:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437986AbgLNC3U (ORCPT ); Sun, 13 Dec 2020 21:29:20 -0500 Received: from ZXSHCAS2.zhaoxin.com ([203.148.12.82]:37360 "EHLO ZXSHCAS2.zhaoxin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730312AbgLNC3T (ORCPT ); Sun, 13 Dec 2020 21:29:19 -0500 Received: from zxbjmbx1.zhaoxin.com (10.29.252.163) by ZXSHCAS2.zhaoxin.com (10.28.252.162) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Mon, 14 Dec 2020 10:28:35 +0800 Received: from [10.32.56.37] (10.32.56.37) by zxbjmbx1.zhaoxin.com (10.29.252.163) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Mon, 14 Dec 2020 10:28:33 +0800 Subject: Re: [PATCH] crypto: x86/crc32c-intel - Don't match some Zhaoxin CPUs To: Eric Biggers CC: , , , , , , , , , , , , , , References: <1607686144-2604-1-git-send-email-TonyWWang-oc@zhaoxin.com> From: Tony W Wang-oc Message-ID: <1f8d17bf-c1d9-6496-d2f8-5773633011fb@zhaoxin.com> Date: Mon, 14 Dec 2020 10:28:19 +0800 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: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.32.56.37] X-ClientProxiedBy: ZXSHCAS1.zhaoxin.com (10.28.252.161) To zxbjmbx1.zhaoxin.com (10.29.252.163) Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org On 12/12/2020 01:43, Eric Biggers wrote: > On Fri, Dec 11, 2020 at 07:29:04PM +0800, Tony W Wang-oc wrote: >> The driver crc32c-intel match CPUs supporting X86_FEATURE_XMM4_2. >> On platforms with Zhaoxin CPUs supporting this X86 feature, When >> crc32c-intel and crc32c-generic are both registered, system will >> use crc32c-intel because its .cra_priority is greater than >> crc32c-generic. This case expect to use crc32c-generic driver for >> some Zhaoxin CPUs to get performance gain, So remove these Zhaoxin >> CPUs support from crc32c-intel. >> >> Signed-off-by: Tony W Wang-oc > > Does this mean that the performance of the crc32c instruction on those CPUs is > actually slower than a regular C implementation? That's very weird. > >From the lmbench3 Create and Delete file test on those chips, I think yes. sincerely Tony