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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 41A64C282CE for ; Tue, 4 Jun 2019 14:29:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 16BF72498E for ; Tue, 4 Jun 2019 14:29:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727663AbfFDO3U (ORCPT ); Tue, 4 Jun 2019 10:29:20 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:50436 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727169AbfFDO3U (ORCPT ); Tue, 4 Jun 2019 10:29:20 -0400 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x54EOJdC002011 for ; Tue, 4 Jun 2019 10:29:18 -0400 Received: from e06smtp03.uk.ibm.com (e06smtp03.uk.ibm.com [195.75.94.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 2swt7grqfv-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 04 Jun 2019 10:29:18 -0400 Received: from localhost by e06smtp03.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 4 Jun 2019 15:29:13 +0100 Received: from b06wcsmtp001.portsmouth.uk.ibm.com (b06wcsmtp001.portsmouth.uk.ibm.com [9.149.105.160]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x54ETB3d35389444 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 4 Jun 2019 14:29:11 GMT Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 59BE4A4064; Tue, 4 Jun 2019 14:29:11 +0000 (GMT) Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id CC03EA4054; Tue, 4 Jun 2019 14:29:10 +0000 (GMT) Received: from oc2783563651 (unknown [9.152.224.145]) by b06wcsmtp001.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 4 Jun 2019 14:29:10 +0000 (GMT) Date: Tue, 4 Jun 2019 16:29:09 +0200 From: Halil Pasic To: Cornelia Huck Cc: Michael Mueller , KVM Mailing List , Linux-S390 Mailing List , Sebastian Ott , Heiko Carstens , virtualization@lists.linux-foundation.org, "Michael S . Tsirkin" , Christoph Hellwig , Thomas Huth , Christian Borntraeger , Viktor Mihajlovski , Vasily Gorbik , Janosch Frank , Claudio Imbrenda , Farhan Ali , Eric Farman Subject: Re: [PATCH v3 7/8] virtio/s390: use DMA memory for ccw I/O and classic notifiers In-Reply-To: <20190604153625.6c03c232.cohuck@redhat.com> References: <20190529122657.166148-1-mimu@linux.ibm.com> <20190529122657.166148-8-mimu@linux.ibm.com> <20190603181716.325101d9.cohuck@redhat.com> <20190604150819.1f8707b5.pasic@linux.ibm.com> <20190604153625.6c03c232.cohuck@redhat.com> Organization: IBM X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.31; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 19060414-0012-0000-0000-000003233B86 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19060414-0013-0000-0000-0000215C1B4E Message-Id: <20190604162909.54de39fb.pasic@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-06-04_10:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=868 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906040096 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, 4 Jun 2019 15:36:25 +0200 Cornelia Huck wrote: > On Tue, 4 Jun 2019 15:08:19 +0200 > Halil Pasic wrote: > [..] > > Two things: > - The call path goes from the vcdev to the vdev, then back to the vcdev > and then to the cdev. Going from the vcdev to the cdev directly > eliminates the roundtrip via the vdev, which I think does not add > anything. > - I prefer > variable = function_returning_a_pointer(...); > over > function_setting_a_variable(..., variable); > The latter obscures the fact that we change the value of the > variable, unless named very obviously. > I understand. Here it's especially bad because what looks like a function is actually a macro so it ain't even fn(..., &variable) but just fn(..., variable). I guess I'm a bit desensitized towards the latter because of my c++ background. > > > > I will change this for v4 as you requested. Again sorry for missing it! > > np, can happen. Thanks for the explanation. I will use ccw_device_dma_zalloc() directly in v4. Regards, Halil