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_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, 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 873A5C4338F for ; Fri, 13 Aug 2021 16:46:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 70D2260E52 for ; Fri, 13 Aug 2021 16:46:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235739AbhHMQqi (ORCPT ); Fri, 13 Aug 2021 12:46:38 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:3650 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229530AbhHMQqg (ORCPT ); Fri, 13 Aug 2021 12:46:36 -0400 Received: from fraeml714-chm.china.huawei.com (unknown [172.18.147.200]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4GmTv86sfxz6FBPV; Sat, 14 Aug 2021 00:45:24 +0800 (CST) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by fraeml714-chm.china.huawei.com (10.206.15.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.8; Fri, 13 Aug 2021 18:46:08 +0200 Received: from [10.47.94.64] (10.47.94.64) by lhreml724-chm.china.huawei.com (10.201.108.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Fri, 13 Aug 2021 17:46:07 +0100 Subject: Re: [PATCH 1/4] iommu/arm-smmu-v3: Use command queue batching helpers to improve performance To: Robin Murphy , Zhen Lei , Will Deacon , Joerg Roedel , linux-arm-kernel , iommu , References: <20210811114852.2429-1-thunder.leizhen@huawei.com> <20210811114852.2429-2-thunder.leizhen@huawei.com> <81258eb7-eb73-8a32-0983-3487daba1167@arm.com> From: John Garry Message-ID: <4e741216-d6e7-c40c-f257-242cd2fea302@huawei.com> Date: Fri, 13 Aug 2021 17:45:23 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.12.1 MIME-Version: 1.0 In-Reply-To: <81258eb7-eb73-8a32-0983-3487daba1167@arm.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Originating-IP: [10.47.94.64] X-ClientProxiedBy: lhreml730-chm.china.huawei.com (10.201.108.81) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 13/08/2021 17:01, Robin Murphy wrote: >> >> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c >> b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c >> index 235f9bdaeaf223b..c81cd929047f573 100644 >> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c >> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c >> @@ -1747,15 +1747,16 @@ static int arm_smmu_atc_inv_master(struct >> arm_smmu_master *master) >>   { >>       int i; >>       struct arm_smmu_cmdq_ent cmd; >> +    struct arm_smmu_cmdq_batch cmds = {}; > > BTW, it looks like this has crossed over with John's patch removing these. It is only called from arm_smmu_disable_ats(), so not hot-path by the look for it. Or who even has ats HW ...? But it should be at least cleaned-up for consistency. Leizhen? Thanks, John