From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <dev-bounces@dpdk.org> Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 21797A0032; Fri, 22 Apr 2022 09:47:00 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id A7D344067B; Fri, 22 Apr 2022 09:46:59 +0200 (CEST) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by mails.dpdk.org (Postfix) with ESMTP id 684A740042 for <dev@dpdk.org>; Fri, 22 Apr 2022 09:46:58 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1650613617; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=cNG1tJBKd2SQPuO93yz9XnMiR2NQpM74stwrcSzM1sc=; b=TZ4s8ePveJxgvf4J5GCQA7XjCngx7SsBBFV3aSpOlimJigqvF9DhMFn7aP/XhHo2zGBAWl GBJMKYHaT2YI6y37fktRuusAFu2eGDtl6UNpxweY1gaSwMUQNxZ92I7bkVaTlG4d0sHzCZ c0LfYf8IV+huyOFhdkD/RkAsNrjMK24= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-633-jyY-jiR1ONWSqBs5zb1ouA-1; Fri, 22 Apr 2022 03:46:51 -0400 X-MC-Unique: jyY-jiR1ONWSqBs5zb1ouA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 15C101E13783; Fri, 22 Apr 2022 07:46:47 +0000 (UTC) Received: from [10.39.208.35] (unknown [10.39.208.35]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B624240D2820; Fri, 22 Apr 2022 07:46:45 +0000 (UTC) Message-ID: <04f973e2-7ab6-957d-0592-e5e75762e52e@redhat.com> Date: Fri, 22 Apr 2022 09:46:44 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 To: David Marchand <david.marchand@redhat.com>, dev@dpdk.org Cc: stephen@networkplumber.org, chenbo.xia@intel.com, jiayu.hu@intel.com, yuanx.wang@intel.com, xuan.ding@intel.com References: <20220328121758.26632-1-david.marchand@redhat.com> <20220411110013.18624-1-david.marchand@redhat.com> <20220411110013.18624-8-david.marchand@redhat.com> From: Maxime Coquelin <maxime.coquelin@redhat.com> Subject: Re: [RFC PATCH v3 7/8] vhost: annotate IOTLB locks In-Reply-To: <20220411110013.18624-8-david.marchand@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.11.54.2 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=maxime.coquelin@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions <dev.dpdk.org> List-Unsubscribe: <https://mails.dpdk.org/options/dev>, <mailto:dev-request@dpdk.org?subject=unsubscribe> List-Archive: <http://mails.dpdk.org/archives/dev/> List-Post: <mailto:dev@dpdk.org> List-Help: <mailto:dev-request@dpdk.org?subject=help> List-Subscribe: <https://mails.dpdk.org/listinfo/dev>, <mailto:dev-request@dpdk.org?subject=subscribe> Errors-To: dev-bounces@dpdk.org On 4/11/22 13:00, David Marchand wrote: > This change simply annotates existing paths of the code leading to > manipulations of the IOTLB r/w locks. > > clang does not support conditionally held locks, so always take iotlb > locks regardless of VIRTIO_F_IOMMU_PLATFORM feature. > > vdpa and vhost_crypto code are annotated though they end up not taking > a IOTLB lock and have been marked with a FIXME. > > Signed-off-by: David Marchand <david.marchand@redhat.com> > --- > lib/vhost/iotlb.h | 8 +++++++ > lib/vhost/vdpa.c | 1 + > lib/vhost/vhost.c | 11 +++++---- > lib/vhost/vhost.h | 22 +++++++++++++----- > lib/vhost/vhost_crypto.c | 7 ++++++ > lib/vhost/virtio_net.c | 49 ++++++++++++++++++++++++++++++---------- > 6 files changed, 75 insertions(+), 23 deletions(-) > I agree with the change. I don't expect performance impact of taking the lock unconditionally, because there won't be cache line sharing since it is per-vq lock and the locking cost will be offset by removing the feature check. Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com> Thanks, Maxime