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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_PASS,UNPARSEABLE_RELAY 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 39AEBC4360F for ; Thu, 4 Apr 2019 03:31:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 01C0A2133D for ; Thu, 4 Apr 2019 03:31:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="wrX2x83D" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726694AbfDDDbu (ORCPT ); Wed, 3 Apr 2019 23:31:50 -0400 Received: from aserp2130.oracle.com ([141.146.126.79]:50954 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726167AbfDDDbu (ORCPT ); Wed, 3 Apr 2019 23:31:50 -0400 Received: from pps.filterd (aserp2130.oracle.com [127.0.0.1]) by aserp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x343OV03039749; Thu, 4 Apr 2019 03:31:43 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=to : cc : subject : from : references : date : in-reply-to : message-id : mime-version : content-type; s=corp-2018-07-02; bh=rvMyld07lEQ9CIWLvUMFMwd4DjXMrssZ6GIzVHFyWlg=; b=wrX2x83DK8g+8HYvPFRHdUm9abehTdipqRdqnY/cmhQCZCU6Slg6/5BsOvtFH3EmXv02 QjNNWIdfCxMhFc94IRjt//93mdl9De1LmHndtgjgHlKNLaWEyBBqz6LPTdsQ4LWWZ3Ie 4li3QvH7oyY8Aq0bTOtwvfm/NULBAczGvWmbxQmOhv02UmpRxkpdGeY3fx4CsIch3d5x OsxA5Uw9uh5fe5tnGarxeTqLwaKg7/SSAR2Q+ZtB5Rx2ThkB952XoUv3ZZq1z3V1NPCB WjQC5uCYWzYIjRL4OvWptQtOK1iOjOtwSag7JXgAPZRoIB9e9jZfi40nq1RMKMiIkzT8 ZQ== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by aserp2130.oracle.com with ESMTP id 2rhwydcq95-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 04 Apr 2019 03:31:43 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x343VJWp114018; Thu, 4 Apr 2019 03:31:43 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by aserp3030.oracle.com with ESMTP id 2rm8f5pjpj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 04 Apr 2019 03:31:43 +0000 Received: from abhmp0019.oracle.com (abhmp0019.oracle.com [141.146.116.25]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x343VgG8009595; Thu, 4 Apr 2019 03:31:42 GMT Received: from ca-mkp.ca.oracle.com (/10.159.214.123) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 03 Apr 2019 20:31:42 -0700 To: Michael Kelley Cc: KY Srinivasan , "martin.petersen\@oracle.com" , Long Li , "James.Bottomley\@hansenpartnership.com" , "emilne\@redhat.com" , "linux-hyperv\@vger.kernel.org" , "linux-kernel\@vger.kernel.org" , "linux-scsi\@vger.kernel.org" Subject: Re: [PATCH 1/1] scsi: storvsc: Reduce default ring buffer size to 128 Kbytes From: "Martin K. Petersen" Organization: Oracle Corporation References: <1554154871-10305-1-git-send-email-mikelley@microsoft.com> Date: Wed, 03 Apr 2019 23:31:39 -0400 In-Reply-To: <1554154871-10305-1-git-send-email-mikelley@microsoft.com> (Michael Kelley's message of "Mon, 1 Apr 2019 21:42:06 +0000") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1.92 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9216 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=686 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904040022 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9216 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=728 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904040022 Sender: linux-hyperv-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hyperv@vger.kernel.org Michael, > Reduce the default VMbus channel ring buffer size for storvsc SCSI > devices from 1 Mbyte to 128 Kbytes. Measurements show that ring buffer > sizes above 128 Kbytes do not increase performance even at very high > IOPS rates, so don't waste the memory. Also remove the dependence on > PAGE_SIZE, since the ring buffer size should not change on > architectures where PAGE_SIZE is not 4 Kbytes. Applied to 5.1/scsi-fixes, thanks. -- Martin K. Petersen Oracle Linux Engineering