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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 C0E89C433E7 for ; Tue, 13 Oct 2020 13:23:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 624FF22CAE for ; Tue, 13 Oct 2020 13:23:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728486AbgJMNX5 (ORCPT ); Tue, 13 Oct 2020 09:23:57 -0400 Received: from mga01.intel.com ([192.55.52.88]:4786 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728407AbgJMNX5 (ORCPT ); Tue, 13 Oct 2020 09:23:57 -0400 IronPort-SDR: MKp5WzwCOrArh5iYmZE2G3EMgD4ZUnDV+qll4evJuH4PoD1cxc29MhGzUxvvNVleIaYOV59kzw /lYwCE+Ty5tg== X-IronPort-AV: E=McAfee;i="6000,8403,9772"; a="183385158" X-IronPort-AV: E=Sophos;i="5.77,370,1596524400"; d="scan'208";a="183385158" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Oct 2020 06:23:56 -0700 IronPort-SDR: Km2AzzYP3D7woTkSWuxQQ/9lLE4thVbSDWmy6FxtdT85iZbRTSUZS3Onsp/m6xqr9p/Fz5tZZd 3XA/y2/QQnkg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.77,370,1596524400"; d="scan'208";a="299568616" Received: from ahunter-desktop.fi.intel.com (HELO [10.237.72.94]) ([10.237.72.94]) by fmsmga007.fm.intel.com with ESMTP; 13 Oct 2020 06:23:54 -0700 Subject: Re: eMMC performance regression caused by 427b6514d0953bf To: Ulf Hansson , Jisheng Zhang Cc: "linux-mmc@vger.kernel.org" References: <20201013190851.715df9ad@xhacker.debian> From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Message-ID: <87a39115-5843-a6a3-7564-e36ae1f16903@intel.com> Date: Tue, 13 Oct 2020 16:23:36 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org On 13/10/20 3:32 pm, Ulf Hansson wrote: > + Adrian > > On Tue, 13 Oct 2020 at 13:09, Jisheng Zhang wrote: >> >> Hi, >> >> I found an emmc performance regression with below simple benchmark cmd: >> >> dd if=/dev/mmcblk0 of=/dev/null bs=8192 count=100000 >> >> This regression has been bisected to commit >> 427b6514d0953bf (“mmc: sdhci: Add Auto CMD Auto Select support”) >> >> If I revert this commit, the performance is good now. >> >> I’m not sure whether this is common issue or not. > > Can you provide some data, like how much is the regression and how > many tests did you run? > > Did you try different block sizes of the dd command? Also what is the SDHCI version? The patch in question is for version >= 4.1 What driver? Can you tell if the patch changed which auto command is used?