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=-2.2 required=3.0 tests=BAYES_00,DATE_IN_PAST_03_06, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 A3845C433EF for ; Thu, 16 Sep 2021 10:53:40 +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 17B7161216 for ; Thu, 16 Sep 2021 10:53:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 17B7161216 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=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-341-ZomHjScsNxaj0LukukzZaA-1; Thu, 16 Sep 2021 06:53:37 -0400 X-MC-Unique: ZomHjScsNxaj0LukukzZaA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 8EC8ECC622; Thu, 16 Sep 2021 10:53:32 +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 A633E60E1C; Thu, 16 Sep 2021 10:53:31 +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 518C31800FE4; Thu, 16 Sep 2021 10:53:30 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id 18GArSAA003772 for ; Thu, 16 Sep 2021 06:53:28 -0400 Received: by smtp.corp.redhat.com (Postfix) id 396E310F99B; Thu, 16 Sep 2021 10:53:28 +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 3337211411E for ; Thu, 16 Sep 2021 10:53:25 +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 21D04858F14 for ; Thu, 16 Sep 2021 10:53:25 +0000 (UTC) Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-405-qKAHbRWUOdqz6KE5JsfiRg-1; Thu, 16 Sep 2021 06:53:20 -0400 X-MC-Unique: qKAHbRWUOdqz6KE5JsfiRg-1 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 3AA112237C; Thu, 16 Sep 2021 10:53:19 +0000 (UTC) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 0700B13CC7; Thu, 16 Sep 2021 10:53:18 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id oiclOx4iQ2E6BQAAMHmgww (envelope-from ); Thu, 16 Sep 2021 10:53:18 +0000 Message-ID: From: Martin Wilck To: Benjamin Marzinski In-Reply-To: <20210915222023.GQ3087@octiron.msp.redhat.com> References: <20210910114120.13665-1-mwilck@suse.com> <20210910114120.13665-6-mwilck@suse.com> <20210915222023.GQ3087@octiron.msp.redhat.com> MIME-Version: 1.0 Date: Thu, 16 Sep 2021 09:10:57 +0200 User-Agent: Evolution 3.40.4 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 2.79 on 10.11.54.5 X-MIME-Autoconverted: from quoted-printable to 8bit by lists01.pubmisc.prod.ext.phx2.redhat.com id 18GArSAA003772 X-loop: dm-devel@redhat.com Cc: lixiaokeng@huawei.com, Chongyun Wu , dm-devel@redhat.com Subject: Re: [dm-devel] [PATCH 05/35] libmultipath: improve cleanup of uevent queues on exit X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: quoted-printable On Wed, 2021-09-15 at 17:20 -0500, Benjamin Marzinski wrote: > On Fri, Sep 10, 2021 at 01:40:50PM +0200, mwilck@suse.com=A0wrote: > > From: Martin Wilck > >=20 > > uevents listed on merge_node must be cleaned up, too. uevents > > cancelled while being serviced and temporary queues, likewise. > > The global uevq must be cleaned out in the uevent listener thread, > > because it might have added events after the dispatcher thread > > had already finished. > >=20 >=20 > There's nothing wrong with this, but for the global list, wouldn't it > be > easier to just wait till after cleanup_child() calls > cleanup_threads(), > and then call cleanup_global_uevq(). That way you know nothing else > is > running. That would be possible. If I understand your proposal correctly, that would require calling cleanup_global_uevq() from cleanup_child(), i.e. from the main process. Currently uevq and the functions handling it are static and only visible in uevent.c. By taking the lock in cleanup_global_uevq() and calling it from the listener on cleanup, I can be sure that the dispatcher won't see any more uevents if it hasn't terminated yet, and that no no events will be added to the queue after cleanup. So I think with this patch I can also be certain that uevq is cleaned up for good, without a need to export the cleanup function, and without enforcing a certain order of thread shutdowns on exit. Do you disagree? Thanks, Martin -- dm-devel mailing list dm-devel@redhat.com https://listman.redhat.com/mailman/listinfo/dm-devel