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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7C966C433F5 for ; Wed, 27 Oct 2021 08:56:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 611A161040 for ; Wed, 27 Oct 2021 08:56:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241085AbhJ0I6i (ORCPT ); Wed, 27 Oct 2021 04:58:38 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:35366 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241105AbhJ0I6c (ORCPT ); Wed, 27 Oct 2021 04:58:32 -0400 Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 19R83lCO011873 for ; Wed, 27 Oct 2021 08:56:07 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding; s=pp1; bh=bQ5fBMldQcrQxbmuap1puq2OVps7MN04aDprEOeA4xk=; b=D4MR0Yqd16T3DGM/84cmdp40ivXct795x5f8DuF9a8M1F3BYFhLsotVqleNfd50OREur jTXbU8+ci48inj1r61PgQzWPGKI6Wb21m9wsrKlGOrIddisHEwMaA/+a5rTXTJ0Or1fS WNUREEGDY7hXRS6UX5nOJVbAORsmd5huBGg7YRVDDBu3xzY3qcEWBtmZwoTgs/UKEt9v ojldlsLuoQfSspDRsSMfwr+XS8831j6Bif3DR1sWVRO7s6fgwQgOcbQrXSH7VEmk+D1H 3fe1uT85GL3PrmZrCakSgBsQQnNSBQlVtamixtjHq1Rm7nAYiXVZfzYafm2n8jOShYF0 fw== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 3bxwecj1gn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 27 Oct 2021 08:56:06 +0000 Received: from m0098404.ppops.net (m0098404.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 19R8ZWwL019142 for ; Wed, 27 Oct 2021 08:56:06 GMT Received: from ppma04fra.de.ibm.com (6a.4a.5195.ip4.static.sl-reverse.com [149.81.74.106]) by mx0a-001b2d01.pphosted.com with ESMTP id 3bxwecj1g1-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 27 Oct 2021 08:56:06 +0000 Received: from pps.filterd (ppma04fra.de.ibm.com [127.0.0.1]) by ppma04fra.de.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 19R8hPVx023047; Wed, 27 Oct 2021 08:51:03 GMT Received: from b06cxnps4076.portsmouth.uk.ibm.com (d06relay13.portsmouth.uk.ibm.com [9.149.109.198]) by ppma04fra.de.ibm.com with ESMTP id 3bx4f7m8cj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 27 Oct 2021 08:51:03 +0000 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 19R8oxmS45023628 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 27 Oct 2021 08:50:59 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B7FF611C06E; Wed, 27 Oct 2021 08:50:59 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8B08711C069; Wed, 27 Oct 2021 08:50:59 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 27 Oct 2021 08:50:59 +0000 (GMT) From: Vineeth Vijayan To: cohuck@redhat.com, linux-s390@vger.kernel.org Cc: oberpar@linux.ibm.com, vneethv@linux.ibm.com Subject: [RFC v2 0/1]s390/cio: remove uevent suppress from cio driver Date: Wed, 27 Oct 2021 10:50:58 +0200 Message-Id: <20211027085059.544736-1-vneethv@linux.ibm.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: XAOB0R2nksXpaLt0UB7WP5GkdeZE08WM X-Proofpoint-ORIG-GUID: VsRiYLHhGW6gEvKI4Mp0F1pNE8yIJdwm X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.182.1,Aquarius:18.0.790,Hydra:6.0.425,FMLib:17.0.607.475 definitions=2021-10-27_02,2021-10-26_01,2020-04-07_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 spamscore=0 mlxscore=0 suspectscore=0 adultscore=0 mlxlogscore=582 phishscore=0 clxscore=1015 malwarescore=0 priorityscore=1501 impostorscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2110150000 definitions=main-2110270052 Precedence: bulk List-ID: X-Mailing-List: linux-s390@vger.kernel.org This is the follow-up for the old RFC which i have posted here couple of months back. During the previous discussions on that RFC we concluded that removing the uevent-suppress from the CIO layer is the cleaner way of doing it and we should proceed. Reason for this RFC is, i want to convince myself that, i am not doing something wrong. I would like to bring up some of the tests i have done and the conclusion from those tests. The reason for introducing the delay in uevent generation was to avoid a uevent storm from those subchannels which does not have a valid device connected on this. I think for the new generation Z machines, this is not inconsequential. The bigger worry was, how this change is going to effect servers with lots of devices connected to them. For example, with this change, we are introducing a new uevent, which was previously suppressed. Below is the udevadm monitor report which shows the uevent generated when we define a new dasd device. $: vmcp def t3390 e002 1 DASD E002 DEFINED KERNEL[53.083552] add /devices/css0/0.0.13af (css) * KERNEL[53.083590] bind /devices/css0/0.0.13af (css) KERNEL[53.086561] add /devices/css0/0.0.13af/0.0.e002 (ccw) KERNEL[53.087136] bind /devices/css0/0.0.13af/0.0.e002 (ccw) This new uvent on css (Which is highlighed with *), does not have a bigger impact on the machines. But, they are useless for those subchannels without a proper device associated with it. We wanted to make sure that this new uevents are not giving bigger impacts on customer machines which would accommodate many more devices on an LPAR. One test to simulate this scenario was to define more than 5000 dasd devices on a zVM and check the boot and initialization delay with and without this patch. This does not show any impact on the zVM with high number of devices. I dont see any specific impact on this patch as of now. But, if you think there is some more testing which are required before we push this patch, please do let me know. Vineeth Vijayan (1): s390/cio: remove uevent suppress from css driver drivers/s390/cio/chsc_sch.c | 5 ----- drivers/s390/cio/css.c | 19 ------------------- drivers/s390/cio/device.c | 18 ------------------ drivers/s390/cio/eadm_sch.c | 5 ----- drivers/s390/cio/vfio_ccw_drv.c | 5 ----- 5 files changed, 52 deletions(-) -- 2.25.1