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=-4.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 1714BC43381 for ; Tue, 2 Apr 2019 07:59:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D257C20856 for ; Tue, 2 Apr 2019 07:59:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="sZJsNgsM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727905AbfDBH7n (ORCPT ); Tue, 2 Apr 2019 03:59:43 -0400 Received: from lelv0143.ext.ti.com ([198.47.23.248]:58428 "EHLO lelv0143.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725884AbfDBH7n (ORCPT ); Tue, 2 Apr 2019 03:59:43 -0400 Received: from fllv0034.itg.ti.com ([10.64.40.246]) by lelv0143.ext.ti.com (8.15.2/8.15.2) with ESMTP id x327xXLK091080; Tue, 2 Apr 2019 02:59:33 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1554191973; bh=4IAx569BJpLqMRnkl/74xkVsHrXMbC8VE2otIjWxnaQ=; h=Subject:To:CC:References:From:Date:In-Reply-To; b=sZJsNgsMr4QQdpNQQnEGSxD2ooynhz/LdsBBB+oFLoYddRbQQ7T3xSsmX16qkSO3v 6bZofQ7MBIlHv4N0DUm3TiI49N8dYpXgt566aJtQw1EknMuABEaX8400ZKKC9osEAt IuGKnguVzWyvPSfxWob9vqI0FHU4VRMiJLasjlow= Received: from DFLE109.ent.ti.com (dfle109.ent.ti.com [10.64.6.30]) by fllv0034.itg.ti.com (8.15.2/8.15.2) with ESMTPS id x327xXQw110303 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 2 Apr 2019 02:59:33 -0500 Received: from DFLE111.ent.ti.com (10.64.6.32) by DFLE109.ent.ti.com (10.64.6.30) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5; Tue, 2 Apr 2019 02:59:32 -0500 Received: from lelv0327.itg.ti.com (10.180.67.183) by DFLE111.ent.ti.com (10.64.6.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5 via Frontend Transport; Tue, 2 Apr 2019 02:59:32 -0500 Received: from [172.24.190.215] (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0327.itg.ti.com (8.15.2/8.15.2) with ESMTP id x327xSTa019623; Tue, 2 Apr 2019 02:59:29 -0500 Subject: Re: [PATCH v2 1/8] mmc: sdhci: Get rid of finish_tasklet To: Adrian Hunter , Ulf Hansson CC: Linux Kernel Mailing List , DTML , "linux-mmc@vger.kernel.org" , linux-omap , Rob Herring , Mark Rutland , Kishon , Chunyan Zhang , Grygorii Strashko References: <20190215192033.24203-1-faiz_abbas@ti.com> <20190215192033.24203-2-faiz_abbas@ti.com> <65f24027-005a-4372-8819-45e6a360bfce@intel.com> From: Faiz Abbas Message-ID: <987a3616-8530-7247-ce00-6513a6c2d4bc@ti.com> Date: Tue, 2 Apr 2019 13:29:10 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.1 MIME-Version: 1.0 In-Reply-To: <65f24027-005a-4372-8819-45e6a360bfce@intel.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Adrian, On 26/03/19 1:03 PM, Adrian Hunter wrote: > On 18/03/19 11:33 AM, Ulf Hansson wrote: >> + Arnd, Grygorii >> >> On Fri, 15 Feb 2019 at 20:17, Faiz Abbas wrote: >>> >>> sdhci.c has two bottom halves implemented. A threaded_irq for handling >>> card insert/remove operations and a tasklet for finishing mmc requests. >>> With the addition of external dma support, dmaengine APIs need to >>> terminate in non-atomic context before unmapping the dma buffers. >>> >>> To facilitate this, remove the finish_tasklet and move the call of >>> sdhci_request_done() to the threaded_irq() callback. Also move the >>> interrupt result variable to sdhci_host so it can be populated from >>> anywhere inside the sdhci_irq handler. >>> >>> Signed-off-by: Faiz Abbas >> >> Adrian, I think it makes sense to apply this patch, even if there is >> very minor negative impact throughput wise. >> >> To me, it doesn't seems like MMC/SD/SDIO has good justification for >> using tasklets, besides from the legacy point of view, of course. >> Instead, I think we should try to move all mmc hosts into using >> threaded IRQs. >> >> So, what do you think? Can you overlook the throughput drop and >> instead we can try to recover this on top with other optimizations? > > I tend to favour good results as expressed here: > > https://lkml.org/lkml/2007/6/22/360 > > So I want to do optimization first. > > But performance is not the only problem with the patch. Give me a few > days and I will see what I can come up with. > Gentle ping on this. Thanks, Faiz