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=-15.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 98480C4361A for ; Fri, 4 Dec 2020 14:28:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6AD7822B3A for ; Fri, 4 Dec 2020 14:28:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729162AbgLDO2T (ORCPT ); Fri, 4 Dec 2020 09:28:19 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:35370 "EHLO mx0b-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726309AbgLDO2T (ORCPT ); Fri, 4 Dec 2020 09:28:19 -0500 Received: from pps.filterd (m0127361.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 0B4E4fP1147939; Fri, 4 Dec 2020 09:27:29 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=pp1; bh=IfM/Ey0nB8wsSk7NCHr8qaeC/s7Q0Ik7M1AN6KkYovk=; b=Q/wVs8rv2oMqXAUKkDGU+VehZCyDPBttmT7K+PJF79yvE0z4W7Q7QlvCALYWN/n1kE5F cYX8PJVMv4No88WzQ85h3SkdxT3ibNTSf4fXBpC61ZW8f8RM9E7VGk83EsA3lpEpVhDP fLKXXaaPs4sLu/eKTOO/Exi7Y7GZWi6K3jziNTQsEfbMhcpV134FRYaphGvU442/7b9F H9oBAh4UUv65IDsZiBjPkwsnuZRAKznU+Qk/RQ69ekG2E9dVY8GNbLnRvbxulTvXUca1 GgaOFEPYDcFBB13ixRvye2TzLd28XFCzX74xjqKBMPPKZIBQ6b4mKjDg/4xzmzLXSnc6 kg== Received: from ppma01wdc.us.ibm.com (fd.55.37a9.ip4.static.sl-reverse.com [169.55.85.253]) by mx0a-001b2d01.pphosted.com with ESMTP id 3577436a1d-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 04 Dec 2020 09:27:29 -0500 Received: from pps.filterd (ppma01wdc.us.ibm.com [127.0.0.1]) by ppma01wdc.us.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 0B4EHZHq021260; Fri, 4 Dec 2020 14:27:24 GMT Received: from b03cxnp08025.gho.boulder.ibm.com (b03cxnp08025.gho.boulder.ibm.com [9.17.130.17]) by ppma01wdc.us.ibm.com with ESMTP id 355vrgb32j-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 04 Dec 2020 14:27:24 +0000 Received: from b03ledav004.gho.boulder.ibm.com (b03ledav004.gho.boulder.ibm.com [9.17.130.235]) by b03cxnp08025.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 0B4EQ8ro19333580 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 4 Dec 2020 14:26:08 GMT Received: from b03ledav004.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B041078074; Fri, 4 Dec 2020 14:26:07 +0000 (GMT) Received: from b03ledav004.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 483A178063; Fri, 4 Dec 2020 14:26:07 +0000 (GMT) Received: from oc6034535106.ibm.com (unknown [9.163.73.174]) by b03ledav004.gho.boulder.ibm.com (Postfix) with ESMTP; Fri, 4 Dec 2020 14:26:07 +0000 (GMT) Subject: Re: [PATCH v2 01/17] ibmvfc: add vhost fields and defaults for MQ enablement To: Tyrel Datwyler , james.bottomley@hansenpartnership.com Cc: martin.petersen@oracle.com, linux-scsi@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, brking@linux.ibm.com References: <20201202005329.4538-1-tyreld@linux.ibm.com> <20201202005329.4538-2-tyreld@linux.ibm.com> <38903a4f-9253-0b4b-6f67-af78ec86175f@linux.ibm.com> From: Brian King Message-ID: Date: Fri, 4 Dec 2020 08:26:06 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.4.0 MIME-Version: 1.0 In-Reply-To: <38903a4f-9253-0b4b-6f67-af78ec86175f@linux.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.312,18.0.737 definitions=2020-12-04_04:2020-12-04,2020-12-04 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxlogscore=999 spamscore=0 priorityscore=1501 mlxscore=0 suspectscore=0 impostorscore=0 lowpriorityscore=0 bulkscore=0 adultscore=0 clxscore=1015 malwarescore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2012040077 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/2/20 11:27 AM, Tyrel Datwyler wrote: > On 12/2/20 7:14 AM, Brian King wrote: >> On 12/1/20 6:53 PM, Tyrel Datwyler wrote: >>> Introduce several new vhost fields for managing MQ state of the adapter >>> as well as initial defaults for MQ enablement. >>> >>> Signed-off-by: Tyrel Datwyler >>> --- >>> drivers/scsi/ibmvscsi/ibmvfc.c | 9 ++++++++- >>> drivers/scsi/ibmvscsi/ibmvfc.h | 13 +++++++++++-- >>> 2 files changed, 19 insertions(+), 3 deletions(-) >>> >>> diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c >>> index 42e4d35e0d35..f1d677a7423d 100644 >>> --- a/drivers/scsi/ibmvscsi/ibmvfc.c >>> +++ b/drivers/scsi/ibmvscsi/ibmvfc.c >>> @@ -5161,12 +5161,13 @@ static int ibmvfc_probe(struct vio_dev *vdev, const struct vio_device_id *id) >>> } >>> >>> shost->transportt = ibmvfc_transport_template; >>> - shost->can_queue = max_requests; >>> + shost->can_queue = (max_requests / IBMVFC_SCSI_HW_QUEUES); >> >> This doesn't look right. can_queue is the SCSI host queue depth, not the MQ queue depth. > > Our max_requests is the total number commands allowed across all queues. From > what I understand is can_queue is the total number of commands in flight allowed > for each hw queue. > > /* > * In scsi-mq mode, the number of hardware queues supported by the LLD. > * > * Note: it is assumed that each hardware queue has a queue depth of > * can_queue. In other words, the total queue depth per host > * is nr_hw_queues * can_queue. However, for when host_tagset is set, > * the total queue depth is can_queue. > */ > > We currently don't use the host wide shared tagset. Ok. I missed that bit... In that case, since we allocate by default only 100 event structs. If we slice that across IBMVFC_SCSI_HW_QUEUES (16) queues, then we end up with only about 6 commands that can be outstanding per queue, which is going to really hurt performance... I'd suggest bumping up IBMVFC_MAX_REQUESTS_DEFAULT from 100 to 1000 as a starting point. Thanks, Brian -- Brian King Power Linux I/O IBM Linux Technology Center