From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (xvm-189-124.dc0.ghst.net [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id CF82AA0524; Thu, 7 Jan 2021 15:47:55 +0100 (CET) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id B59A7140FA8; Thu, 7 Jan 2021 15:47:55 +0100 (CET) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [63.128.21.124]) by mails.dpdk.org (Postfix) with ESMTP id 23F86140FA7 for ; Thu, 7 Jan 2021 15:47:54 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1610030873; 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=BBrTwdAKO+A2pWefl5LX3Y9H0W3kJgfaooZdyuC6qXE=; b=B6S8VzfjNRLCIBXpM9FNR+OGPl00vKpdONhv68QS93TsohyTM6m+6RzDrR/IRi+g8LF4p6 h4glfjDJuAM9zdL1UUSLREDVmdnGKV/wYJeptD+D4U73xvXk7OpqRG0bJGmeTu/z7OMLMX gP9gc9EStAcXuihvY5hLGZm7CcPSySI= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-392-IOiMpwRbOUyGTZ6tgrRQ8A-1; Thu, 07 Jan 2021 09:47:49 -0500 X-MC-Unique: IOiMpwRbOUyGTZ6tgrRQ8A-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 43A62100F7C9; Thu, 7 Jan 2021 14:47:11 +0000 (UTC) Received: from [10.36.110.9] (unknown [10.36.110.9]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9215D5C67A; Thu, 7 Jan 2021 14:47:09 +0000 (UTC) To: Joyce Kong , chenbo.xia@intel.com, honnappa.nagarahalli@arm.com, ruifeng.wang@arm.com Cc: dev@dpdk.org, nd@arm.com References: <20201221142321.51606-1-joyce.kong@arm.com> <20201221142321.51606-4-joyce.kong@arm.com> From: Maxime Coquelin Message-ID: Date: Thu, 7 Jan 2021 15:47:07 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <20201221142321.51606-4-joyce.kong@arm.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 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-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH v1 3/4] net/virtio: replace full barrier with relaxed barrier for Arm platform X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 12/21/20 3:23 PM, Joyce Kong wrote: > Relax the full write barriers to one-way barriers for virtio > control path for Arm platform > > Signed-off-by: Joyce Kong > Reviewed-by: Ruifeng Wang > --- > drivers/net/virtio/virtio_ethdev.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c > index 0d91f7a50..b3e5cba70 100644 > --- a/drivers/net/virtio/virtio_ethdev.c > +++ b/drivers/net/virtio/virtio_ethdev.c > @@ -203,8 +203,8 @@ virtio_send_command_packed(struct virtnet_ctl *cvq, > vq->vq_packed.cached_flags ^= VRING_PACKED_DESC_F_AVAIL_USED; > } > > - virtio_wmb(vq->hw->weak_barriers); > - desc[head].flags = VRING_DESC_F_NEXT | flags; > + virtqueue_store_flags_packed(&desc[head], VRING_DESC_F_NEXT | flags, > + vq->hw->weak_barriers); > > virtio_wmb(vq->hw->weak_barriers); > virtqueue_notify(vq); > Performance does not matter in the case of ctrl queue, but it is cleaner to reuse existing helpers anyway: Reviewed-by: Maxime Coquelin Thanks, Maxime