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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY autolearn=no 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 6368DC3F68F for ; Wed, 18 Dec 2019 03:40:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 344CD21582 for ; Wed, 18 Dec 2019 03:40:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="jVGSSstu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726496AbfLRDkB (ORCPT ); Tue, 17 Dec 2019 22:40:01 -0500 Received: from aserp2120.oracle.com ([141.146.126.78]:59848 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726454AbfLRDkB (ORCPT ); Tue, 17 Dec 2019 22:40:01 -0500 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id xBI3dbKd117311; Wed, 18 Dec 2019 03:39:37 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-2019-08-05; bh=8IAu41A0ROVfnDWMZhCpBuGeJC+jZ2Wigf/4tr6lnzM=; b=jVGSSstumhiA6eWydK51KgVcr9RgGcwslrbhh28s0pNJalGmNqBqg2x8/GDGsslkrH9E Suzgnc7JfszD2CH+QQ1vgu0XAAHZFVLXbiyr0BzZqeP3ypK9g7SknPmnpE6uPqanM7lT UaykzEV+5ZG0i7OFamBFq7NUm+DufGD2i2awn+/YXlE+PBfc1U0kWxPwCEPU0Sts+X+3 K6kN27SlC+i8DXVvudga8LXIuqzdO91Bgu1S17UCUOtfGcqvwq7aRAXS3AbBlt8p5X7D PSXnO6FONm3LwqSUR7Sao8c4pOCYJMwUeuM0nxhnpyTNX7/eo4ngl3u192OPEr7M+0bE wA== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by aserp2120.oracle.com with ESMTP id 2wvqpqav23-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 18 Dec 2019 03:39:37 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.27/8.16.0.27) with SMTP id xBI3dPB7078330; Wed, 18 Dec 2019 03:39:37 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userp3020.oracle.com with ESMTP id 2wxm5pbcdv-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 18 Dec 2019 03:39:36 +0000 Received: from abhmp0020.oracle.com (abhmp0020.oracle.com [141.146.116.26]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id xBI3dTJu021649; Wed, 18 Dec 2019 03:39:29 GMT Received: from ca-mkp.ca.oracle.com (/10.159.214.123) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 17 Dec 2019 19:39:29 -0800 To: Guenter Roeck Cc: "Martin K. Petersen" , Linus Walleij , linux-hwmon@vger.kernel.org, Jean Delvare , Linux Doc Mailing List , "linux-kernel\@vger.kernel.org" , linux-scsi@vger.kernel.org, linux-ide@vger.kernel.org, Chris Healy Subject: Re: [PATCH 1/1] hwmon: Driver for temperature sensors on SATA drives From: "Martin K. Petersen" Organization: Oracle Corporation References: <20191209052119.32072-1-linux@roeck-us.net> <20191209052119.32072-2-linux@roeck-us.net> <541a7ddd-f4c9-5d5f-4f43-0ae5bc46aef6@roeck-us.net> Date: Tue, 17 Dec 2019 22:39:26 -0500 In-Reply-To: (Guenter Roeck's message of "Mon, 16 Dec 2019 20:20:57 -0800") 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=6000 definitions=9474 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=790 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1911140001 definitions=main-1912180026 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9474 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=848 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1911140001 definitions=main-1912180026 Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org Guenter, > If there are 100 physical drives, you would actually want to see the > temperature of each drive separately, as one of them might be > overheating due to some internal failure. Yep. However, for "big boxes" you'll typically get that information from SAF-TE or SES enclosure services and not from the drive itself. SES allows you to monitor power supplies, drive bays, hot swap events, thermals, etc. We have a SES driver in SCSI that exposes all these things in sysfs. It is not currently tied into hwmon. > If the storage array is represented to the system as single huge > physical drive, which is then split into logical entities not related > to physical drives, I guess that would represent a problem for system > management overall. Yep. That's why there's dedicated plumbing in smartmontools to handle various RAID controller interfaces for accessing physical drive information. It's typically highly vendor-specific. > I would not mind to tie the hardware monitoring device to something > else than the scsi device if the scsi device does not always have a > physical representation. Is there a way to determine if a scsi device > is virtual or real ? Not really. Target is usually a pretty good approximation, although some arrays introduce virtual targets because of limited LUN (scsi_device) numbering capabilities. However, arrays generally don't support per-LUN temperature because it makes no sense. I'm trying to gauge how much a pain potentially redundant sensors would be for userland monitoring tooling vs. how many oddball devices we'd not be able to support if we were to use scsi_target as parent (or restrict the sensor binding to LUN 0). -- Martin K. Petersen Oracle Linux Engineering