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 653F8C04E84 for ; Thu, 16 May 2019 13:59:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3D35620848 for ; Thu, 16 May 2019 13:59:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727742AbfEPN7c (ORCPT ); Thu, 16 May 2019 09:59:32 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:48804 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727717AbfEPN7b (ORCPT ); Thu, 16 May 2019 09:59:31 -0400 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x4GDs3Qs136856 for ; Thu, 16 May 2019 09:59:30 -0400 Received: from e06smtp07.uk.ibm.com (e06smtp07.uk.ibm.com [195.75.94.103]) by mx0b-001b2d01.pphosted.com with ESMTP id 2sh8mv9su6-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 16 May 2019 09:59:30 -0400 Received: from localhost by e06smtp07.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) Thu, 16 May 2019 14:59:25 +0100 Received: from d06av24.portsmouth.uk.ibm.com (mk.ibm.com [9.149.105.60]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x4GDxNsh19726444 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 16 May 2019 13:59:23 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 7E3274203F; Thu, 16 May 2019 13:59:23 +0000 (GMT) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id EB51042042; Thu, 16 May 2019 13:59:22 +0000 (GMT) Received: from dyn-9-152-212-110.boeblingen.de.ibm.com (unknown [9.152.212.110]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Thu, 16 May 2019 13:59:22 +0000 (GMT) Date: Thu, 16 May 2019 15:59:22 +0200 (CEST) From: Sebastian Ott X-X-Sender: sebott@schleppi To: Halil Pasic cc: Cornelia Huck , kvm@vger.kernel.org, linux-s390@vger.kernel.org, Martin Schwidefsky , 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 , Michael Mueller Subject: Re: [PATCH 05/10] s390/cio: introduce DMA pools to cio In-Reply-To: <20190512202256.5517592d.pasic@linux.ibm.com> References: <20190426183245.37939-1-pasic@linux.ibm.com> <20190426183245.37939-6-pasic@linux.ibm.com> <20190508232210.5a555caa.pasic@linux.ibm.com> <20190509121106.48aa04db.cohuck@redhat.com> <20190510001112.479b2fd7.pasic@linux.ibm.com> <20190510161013.7e697337.cohuck@redhat.com> <20190512202256.5517592d.pasic@linux.ibm.com> User-Agent: Alpine 2.21 (LFD 202 2017-01-01) Organization: =?ISO-8859-15?Q?=22IBM_Deutschland_Research_&_Development_GmbH?= =?ISO-8859-15?Q?_=2F_Vorsitzende_des_Aufsichtsrats=3A_Matthias?= =?ISO-8859-15?Q?_Hartmann_Gesch=E4ftsf=FChrung=3A_Dirk_Wittkopp?= =?ISO-8859-15?Q?_Sitz_der_Gesellschaft=3A_B=F6blingen_=2F_Reg?= =?ISO-8859-15?Q?istergericht=3A_Amtsgericht_Stuttgart=2C_HRB_2432?= =?ISO-8859-15?Q?94=22?= MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-TM-AS-GCONF: 00 x-cbid: 19051613-0028-0000-0000-0000036E602A X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19051613-0029-0000-0000-0000242DFB1E Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-05-16_11:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=3 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=923 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1905160092 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Sun, 12 May 2019, Halil Pasic wrote: > I've also got code that deals with AIRQ_IV_CACHELINE by turning the > kmem_cache into a dma_pool. > > Cornelia, Sebastian which approach do you prefer: > 1) get rid of cio_dma_pool and AIRQ_IV_CACHELINE, and waste a page per > vector, or > 2) go with the approach taken by the patch below? We only have a couple of users for airq_iv: virtio_ccw.c: 2K bits pci with floating IRQs: <= 2K (for the per-function bit vectors) 1..4K (for the summary bit vector) pci with CPU directed IRQs: 2K (for the per-CPU bit vectors) 1..nr_cpu (for the summary bit vector) The options are: * page allocations for everything * dma_pool for AIRQ_IV_CACHELINE ,gen_pool for others * dma_pool for everything I think we should do option 3 and use a dma_pool with cachesize alignment for everything (as a prerequisite we have to limit config PCI_NR_FUNCTIONS to 2K - but that is not a real constraint). Sebastian