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=-11.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 3200AC2BB48 for ; Mon, 14 Dec 2020 20:42:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D89C822473 for ; Mon, 14 Dec 2020 20:42:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2503472AbgLNUmF (ORCPT ); Mon, 14 Dec 2020 15:42:05 -0500 Received: from mail.kernel.org ([198.145.29.99]:34152 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2503465AbgLNUmA (ORCPT ); Mon, 14 Dec 2020 15:42:00 -0500 Date: Mon, 14 Dec 2020 12:41:18 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1607978479; bh=bZ5V7cOF7Y3xEFjRNlJqO2zCRUqXweheRPkf/g8LBCE=; h=From:To:Cc:Subject:References:In-Reply-To:From; b=q/SHUzEA9Fb7pfRUiNH3yy5W3V2/z/6ZJ41cbKshqUZC7G7kjPc0LeyPXmKO1kGfQ B5/WkyrjNdgEBTpCSLTNsldwIkF57ta9xS2jV6GJls1roMtGCM7JIkhnOre+W7/U+X y4y2LYeQSWM8l8FKZTarm2+1jEdRBeL2iEmHxyEADkq27oiXc4uovchXd5TWWXmScs QtFRIJipqi7+HIL5z4zG91R3kPvU1M04YeVqg5nQ/kCOI7SRRoO+sjLwFys/Jxwozc eKVdosF3I8Q2WrqpGhKhCQKDHc0+z78WvVts/XyYxgX7qf63IJhT9+wFNVEdfeIBP1 5m4zUr/fqa+1Q== From: Eric Biggers To: Tony W Wang-oc Cc: herbert@gondor.apana.org.au, davem@davemloft.net, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, TimGuo-oc@zhaoxin.com, CooperYan@zhaoxin.com, QiyuanWang@zhaoxin.com, HerryYang@zhaoxin.com, CobeChen@zhaoxin.com, SilviaZhao@zhaoxin.com Subject: Re: [PATCH] crypto: x86/crc32c-intel - Don't match some Zhaoxin CPUs Message-ID: References: <1607686144-2604-1-git-send-email-TonyWWang-oc@zhaoxin.com> <1f8d17bf-c1d9-6496-d2f8-5773633011fb@zhaoxin.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1f8d17bf-c1d9-6496-d2f8-5773633011fb@zhaoxin.com> Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org On Mon, Dec 14, 2020 at 10:28:19AM +0800, Tony W Wang-oc wrote: > 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. > Did you try measuring the performance of the hashing itself, and not some higher-level filesystem operations? - Eric