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=-2.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,PDS_BAD_THREAD_QP_64, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 90D9DC4743D for ; Tue, 8 Jun 2021 06:29:58 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 21819611BD for ; Tue, 8 Jun 2021 06:29:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 21819611BD Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=tempfail smtp.mailfrom=linux-lvm-bounces@redhat.com Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-21-3aDHWJF0Mxq5YxU67bTDIQ-1; Tue, 08 Jun 2021 02:29:55 -0400 X-MC-Unique: 3aDHWJF0Mxq5YxU67bTDIQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B924E1854E2A; Tue, 8 Jun 2021 06:29:49 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.20]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 8ADC7100EB3D; Tue, 8 Jun 2021 06:29:49 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id 0192B18033F6; Tue, 8 Jun 2021 06:29:49 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id 157FjXIo013639 for ; Mon, 7 Jun 2021 11:45:33 -0400 Received: by smtp.corp.redhat.com (Postfix) id 22BF32039D96; Mon, 7 Jun 2021 15:45:33 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast01.extmail.prod.ext.rdu2.redhat.com [10.11.55.17]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1D15E204402C for ; Mon, 7 Jun 2021 15:45:28 +0000 (UTC) Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [207.211.31.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 65F6890DE46 for ; Mon, 7 Jun 2021 15:45:28 +0000 (UTC) Received: from de-smtp-delivery-102.mimecast.com (de-smtp-delivery-102.mimecast.com [194.104.109.102]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-377-mDMknP03PQ-uzyA9gVpVyg-1; Mon, 07 Jun 2021 11:45:26 -0400 X-MC-Unique: mDMknP03PQ-uzyA9gVpVyg-1 Received: from EUR05-VI1-obe.outbound.protection.outlook.com (mail-vi1eur05lp2176.outbound.protection.outlook.com [104.47.17.176]) (Using TLS) by relay.mimecast.com with ESMTP id de-mta-11-dd9HYBrlNBaLCvWdFJI8qQ-1; Mon, 07 Jun 2021 17:45:24 +0200 X-MC-Unique: dd9HYBrlNBaLCvWdFJI8qQ-1 Received: from DB8PR04MB6555.eurprd04.prod.outlook.com (2603:10a6:10:103::20) by DBBPR04MB7577.eurprd04.prod.outlook.com (2603:10a6:10:206::10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4195.24; Mon, 7 Jun 2021 15:45:21 +0000 Received: from DB8PR04MB6555.eurprd04.prod.outlook.com ([fe80::1061:e932:29cc:2a38]) by DB8PR04MB6555.eurprd04.prod.outlook.com ([fe80::1061:e932:29cc:2a38%7]) with mapi id 15.20.4195.030; Mon, 7 Jun 2021 15:45:21 +0000 From: Martin Wilck To: Heming Zhao , "linux-lvm@redhat.com" , "rogerheflin@gmail.com" Thread-Topic: [linux-lvm] Discussion: performance issue on event activation mode Thread-Index: AQHXWptdVb+iQI7pP06gMwUhQri0uKsHLrMAgAEreYCAAFSvgIAABC2A Date: Mon, 7 Jun 2021 15:45:21 +0000 Message-ID: References: <7522886d-bfba-6dd6-882a-703d5776e71f@suse.com> In-Reply-To: <7522886d-bfba-6dd6-882a-703d5776e71f@suse.com> Accept-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: user-agent: Evolution 3.40.1 x-originating-ip: [2.206.153.60] x-ms-publictraffictype: Email x-ms-office365-filtering-correlation-id: 5ce61785-af60-4899-ae93-08d929cb4262 x-ms-traffictypediagnostic: DBBPR04MB7577: x-ms-exchange-transport-forked: True x-microsoft-antispam-prvs: x-ms-oob-tlc-oobclassifiers: OLM:9508 x-ms-exchange-senderadcheck: 1 x-microsoft-antispam: BCL:0 x-microsoft-antispam-message-info: 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 x-forefront-antispam-report: CIP:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:DB8PR04MB6555.eurprd04.prod.outlook.com; PTR:; CAT:NONE; SFS:(39860400002)(346002)(376002)(396003)(136003)(366004)(8676002)(2616005)(44832011)(110136005)(53546011)(4326008)(8936002)(316002)(54906003)(91956017)(66556008)(186003)(26005)(478600001)(64756008)(66446008)(66476007)(66946007)(6486002)(71200400001)(86362001)(6512007)(36756003)(38100700002)(122000001)(76116006)(5660300002)(83380400001)(6506007)(2906002); DIR:OUT; SFP:1101 x-ms-exchange-antispam-messagedata: =?iso-8859-15?Q?fXJsht+5YuHKIzyAiWtNBlsaod4Lwe5qQR5oY1qU2RqARa6SIOrFSJ6nx?= =?iso-8859-15?Q?vnwLns0J7bfpt7ZJau4Dt1sELjdhd+IT5d6SN1vCdipZqDdKgKuo9hZP0?= =?iso-8859-15?Q?PxNc3CNk5k9aoIt981FeQJBSY7hKG86OB9at4spJt0ZeeI9tPFh4i3q78?= =?iso-8859-15?Q?AldtVcNSWp7JEDDbItCB9pjgX/HK/PxC8FmrOkaplGtJ/kumFk9BpgpPQ?= =?iso-8859-15?Q?CnXoYuVmkbj4vbIfESfJP/2ygeaIOzgkV9VjXW2KVqBhTBkcHPwvbNlIA?= =?iso-8859-15?Q?mChMyVeRFAisKS6gDzByvGAImurknhqieTLhjfQ38qQA5TloWhWnvLhnD?= =?iso-8859-15?Q?CA7F4PqdqvbLWqkPsRfWiEWfVnjHSwDDmLxGK1MNvTPpOymrM15rfmkfc?= =?iso-8859-15?Q?ujpkwtmnCE5haw8Pvn4hnoJ6fecOksOrUHSuQ3CyU79Y3fbDpVqT3JdeM?= =?iso-8859-15?Q?JGMbqSD7I8/6/cYk0wAHKQEs2wX/mmedVtZeIvnAsjqGUQSl0XQxD/vRN?= =?iso-8859-15?Q?+gY3Yjcm81dzkY02iRXgar1f9R8ucJwGYFH8Z5HGVPGjDsYr0TfB5deyn?= =?iso-8859-15?Q?GBw/6bBVFQzK57SmkGYGERH1vZookPg60ZkrcfIl0TIZMG3ITHSuCVoof?= =?iso-8859-15?Q?ZXN8YAGtbBPJOGeymd02UdOJRpMvRmFlA1LS2mkh3hR2UN/lssobMu/XN?= =?iso-8859-15?Q?2Jn90J3eoYgweKjwbj+dJJe/HefIsWW1ktCxNsrKpEkN2TwYRV41qPKHG?= =?iso-8859-15?Q?rb/Gl+2+55askVETPIMu7d96dcMLwvjeQJ4U1W8SkcJT7T7r85noTvAyu?= =?iso-8859-15?Q?E8V7qIAnIE/zhNnUq+bmUEhcE+hUBnfBHRmDZl2NVTfO0vWDhXaqnnV+J?= =?iso-8859-15?Q?ITBl1dhXcfBBvH7iaD5FCBoZjoi7ITnQi4fFJAFpDHIuHeqpaiZpGsmM6?= =?iso-8859-15?Q?UD8tsabHZoKavTvEZMeZxx6A9ElAy6+WKZGmpyImQJF0Q8pMRj9XJdGqn?= =?iso-8859-15?Q?8wNTfWYAGBPJ0TB1487QqPlZCKMKI/HGkv48AR4P8+s+6X8/MDe9Kple3?= =?iso-8859-15?Q?2Rl6ccprJGXgqqtbnXhcXhY29aRqfUCjbzsKuW9SjnlB3Tylf8bSMgzS/?= =?iso-8859-15?Q?5thEOxTS8lA9UhJDAryDDSYoMeNnIgn6yY+URm2fOCrEv8zhU5v1QVQYT?= =?iso-8859-15?Q?X1b95ao6pTYym9UQh2qMRAOkhDqNcdDsl9LkOy/Zd8uvTocRfusG2HtCW?= =?iso-8859-15?Q?V1mwYaj1kmosdtCL0Kj/sUizkX6b+nfzrDlRdx7WdCHLtYaKVN86/o8G4?= =?iso-8859-15?Q?uabYKhYGpue1kMOyavWiC3BqxmHMpI2t17jF61GI+j6lKCVJB0ir2Yy3Y?= =?iso-8859-15?Q?F8JWu1W3OZ8EAZP0jfhLsAvd15nlnEu3Q?= MIME-Version: 1.0 X-OriginatorOrg: suse.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: DB8PR04MB6555.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: 5ce61785-af60-4899-ae93-08d929cb4262 X-MS-Exchange-CrossTenant-originalarrivaltime: 07 Jun 2021 15:45:21.7929 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: f7a17af6-1c5c-4a36-aa8b-f5be247aa4ba X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: 0E4LR0lCP8l1NlovJRE7hPME/TzzXLRXQKvc6VzRlbZ74sJL58TlYwF5MfDMDrlsJGKyHcecZxvS77wEpG2MTw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DBBPR04MB7577 X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-MIME-Autoconverted: from quoted-printable to 8bit by lists01.pubmisc.prod.ext.phx2.redhat.com id 157FjXIo013639 X-loop: linux-lvm@redhat.com X-Mailman-Approved-At: Tue, 08 Jun 2021 02:29:10 -0400 Cc: "teigland@redhat.com" , "zkabelac@redhat.com" Subject: Re: [linux-lvm] Discussion: performance issue on event activation mode X-BeenThere: linux-lvm@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-lvm-bounces@redhat.com Errors-To: linux-lvm-bounces@redhat.com X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=linux-lvm-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-ID: Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: quoted-printable On Mo, 2021-06-07 at 23:30 +0800, heming.zhao@suse.com wrote: > On 6/7/21 6:27 PM, Martin Wilck wrote: > > On So, 2021-06-06 at 11:35 -0500, Roger Heflin wrote: > > > This might be a simpler way to control the number of threads at > > > the > > > same time. > > >=20 > > > On large machines (cpu wise, memory wise and disk wise).=A0=A0 I have > > > only seen lvm timeout when udev_children is set to default. =A0 The > > > default seems to be set wrong, and the default seemed to be tuned > > > for > > > a case where a large number of the disks on the machine were > > > going to > > > be timing out (or otherwise really really slow), so to support > > > this > > > case a huge number of threads was required..=A0 =A0 I found that with > > > it > > > set to default on a close to 100 core machine that udev got about > > > 87 > > > minutes of time during the boot up (about 2 minutes).=A0 Changing > > > the > > > number of children to =3D4 resulted in udev getting around 2-3 > > > minutes > > > in the same window, and actually resulted in a much faster boot > > > up > > > and a much more reliable boot up (no timeouts). > >=20 > > Wow, setting the number of children to 4 is pretty radical. We > > decrease > > this parameter often on large machines, but we never went all the > > way > > down to a single-digit number. If that's really necessary under > > whatever circumstances, it's clear evidence of udev's deficiencies. > >=20 > > I am not sure if it's better than Heming's suggestion though. It > > would > > affect every device in the system. It wouldn't even be possible to > > process more than 4 totally different events at the same time. > >=20 >=20 > hello >=20 > I tested udev.children_max with value 1, 2 & 4. The results showed it > didn't take effect, and the booting time even longer than before. > This solution may suite for some special cases. Thanks, good to know. There may be other scenarios where Roger's suggestion might help. But it should be clear that no distribution will ever use such low limits, because it'd slow down booting on other systems unnecessarily. Thanks, Martin _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://listman.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/