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=-7.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 7ACE0C4743E for ; Tue, 8 Jun 2021 16:03:09 +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 24EE2610A2 for ; Tue, 8 Jun 2021 16:03:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 24EE2610A2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=tempfail smtp.mailfrom=linux-lvm-bounces@redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1623168188; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:list-id:list-help: list-unsubscribe:list-subscribe:list-post; bh=aaida2AcDCDb8D/QeIxSCdcwgRvW8Mcs6dSO9mO5SU4=; b=Rgw9iAI67NjUd8pDo+wEArZ46cR875mbLwaddnlhj10eD7U3esxX3OwXL0gbNBCgppTYro 7DFRJb+IQDqVLq3DCzVjUuvDcxfC18BM4nzIRVQN8/Y+6TisZ33xz/5/ZpcWqw8kM8ZT2l ux8WwOlmq1TXlXPP9yVHeLdpWgDLtJg= 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-157-BcqXtK5SMaGbe-oP2LZtBQ-1; Tue, 08 Jun 2021 12:03:06 -0400 X-MC-Unique: BcqXtK5SMaGbe-oP2LZtBQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1DE4E107ACE4; Tue, 8 Jun 2021 16:02:58 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 5D3CD620DE; Tue, 8 Jun 2021 16:02:57 +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 3534F44A5A; Tue, 8 Jun 2021 16:02:51 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id 158G2mNZ018707 for ; Tue, 8 Jun 2021 12:02:48 -0400 Received: by smtp.corp.redhat.com (Postfix) id AC55B10016F8; Tue, 8 Jun 2021 16:02:48 +0000 (UTC) Received: from [10.40.194.232] (unknown [10.40.194.232]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5FCD5100760F; Tue, 8 Jun 2021 16:02:44 +0000 (UTC) To: Martin Wilck , "teigland@redhat.com" References: <20210607213003.GA8181@redhat.com> <1760ea9715bc7a16d4efe10dd95105d663a07228.camel@suse.com> <20210608153937.GA21355@redhat.com> From: Zdenek Kabelac Message-ID: <8df4f1b8-8ef2-455f-de81-ed0dda70a6ea@redhat.com> Date: Tue, 8 Jun 2021 18:02:43 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Firefox/78.0 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-loop: linux-lvm@redhat.com Cc: "rogerheflin@gmail.com" , "linux-lvm@redhat.com" , "prajnoha@redhat.com" , Heming Zhao 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 2.79 on 10.5.11.11 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-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="iso-8859-15"; Format="flowed" Dne 08. 06. 21 v 17:47 Martin Wilck napsal(a): > On Di, 2021-06-08 at 10:39 -0500, David Teigland wrote: >> . Use both native md/mpath detection *and* udev info when it's >> readily >> =A0 available (don't wait for it), instead of limiting ourselves to one >> =A0 source of info.=A0 If either source indicates an md/mpath component= , >> =A0 then we consider it true. > Hm. You can boot with "multipath=3Doff" which udev would take into > account. What would you do in that case? Native mpath detection would > probably not figure it out. > > multipath-tools itself follows the "try udev and fall back to native if > it fails" approach, which isn't always perfect, either. > >> A third related improvement that could follow is to add stronger >> native >> mpath detection, in which lvm uses uses /etc/multipath/wwids, >> directly or >> through a multipath library, to identify mpath components.=A0 This >> would >> supplement the existing sysfs and udev sources, and address the >> difficult >> case where the mpath device is not yet set up. >> > Please don't. Use libmpathvalid if you want to improve in this area. > That's what it was made for. Problem is addition of another dependency here. We may probably think about using=A0 'dlopen' and if library is present use= it,=20 but IMHO=A0 libmpathvalid should be integrated into libblkid=A0 in some way= =A0 -=20 linking another library to many other projects that needs to detect MP devi= ces=20 really complicates this a lot.=A0 libblkid should be able to decode this an= d=20 make things much cleaner. I'd also vote for lvm2 plugin for blkid as forking thousands of process sim= ply=20 always will take a lot of time (but this would require quite some code=20 shufling withing lvm codebase). Zdenek _______________________________________________ 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/