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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,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 291EDC6377D for ; Thu, 22 Jul 2021 13:54:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 082566135C for ; Thu, 22 Jul 2021 13:54:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232208AbhGVNOT (ORCPT ); Thu, 22 Jul 2021 09:14:19 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:3450 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231925AbhGVNOS (ORCPT ); Thu, 22 Jul 2021 09:14:18 -0400 Received: from fraeml701-chm.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4GVtyD4mF5z6DHHy; Thu, 22 Jul 2021 21:45:56 +0800 (CST) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by fraeml701-chm.china.huawei.com (10.206.15.50) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Thu, 22 Jul 2021 15:54:51 +0200 Received: from [10.47.26.161] (10.47.26.161) by lhreml724-chm.china.huawei.com (10.201.108.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2176.2; Thu, 22 Jul 2021 14:54:51 +0100 Subject: Re: [bug report] iommu_dma_unmap_sg() is very slow then running IO from remote numa node To: Marc Zyngier CC: Ming Lei , Robin Murphy , , Will Deacon , , , References: <23e7956b-f3b5-b585-3c18-724165994051@arm.com> <74537f9c-af5f-cd84-60ab-49ca6220310e@huawei.com> <9c929985-4fcb-e65d-0265-34c820b770ea@huawei.com> <411dfc7cd330df1f681137d77e846b78@misterjones.org> From: John Garry Message-ID: Date: Thu, 22 Jul 2021 14:54:44 +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: <411dfc7cd330df1f681137d77e846b78@misterjones.org> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Originating-IP: [10.47.26.161] X-ClientProxiedBy: lhreml706-chm.china.huawei.com (10.201.108.55) 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 22/07/2021 13:53, Marc Zyngier wrote: > Hi John, > > [...] > >>     Your kernel log should show: >>     [    0.000000] GICv3: Pseudo-NMIs enabled using forced ICC_PMR_EL1 >> synchronisation > > Unrelated, but you seem to be running with ICC_CTLR_EL3.PMHE set, > which makes the overhead of pseudo-NMIs much higher than it should be > (you take a DSB SY on each interrupt unmasking). > > If you are not using 1:N distribution of SPIs on the secure side, > consider turning that off in your firmware. This should make NMIs > slightly more pleasant to use. Thanks for the hint. I speak to the BIOS guys. John