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=-15.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 595B2C4708F for ; Tue, 1 Jun 2021 21:30:44 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 0111D613B4 for ; Tue, 1 Jun 2021 21:30:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0111D613B4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:56346 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1loByE-0007Y9-Tv for qemu-devel@archiver.kernel.org; Tue, 01 Jun 2021 17:30:42 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:58288) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1loBwv-0006OK-Jn for qemu-devel@nongnu.org; Tue, 01 Jun 2021 17:29:23 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:37832) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1loBwt-0000fi-4r for qemu-devel@nongnu.org; Tue, 01 Jun 2021 17:29:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1622582957; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=kKe02AX6eUu56AZG6fv4u2VZcT6820q0YzoA/2BfL9E=; b=CvmHs6EgAOo7/SWOftfnUXkvrq+QP5C3I/h78voGRXR90swvCp3qAddTnlezgoQfagHZvF FgFvsQRpKnlu0QU61SSLElt6Gq4fhUdZN/5yyjhbh3+cr71xuUFMFShc8iCypBug6avS0Q Drh+VQ+0DfT1lK2b+zw6ewh8YmktWPI= 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-329-1qZB5DxyPsiiQk4ndskP1Q-1; Tue, 01 Jun 2021 17:29:14 -0400 X-MC-Unique: 1qZB5DxyPsiiQk4ndskP1Q-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1F93B100945E; Tue, 1 Jun 2021 21:29:13 +0000 (UTC) Received: from redhat.com (ovpn-113-154.phx2.redhat.com [10.3.113.154]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 899CD608DB; Tue, 1 Jun 2021 21:29:09 +0000 (UTC) Date: Tue, 1 Jun 2021 16:29:07 -0500 From: Eric Blake To: Sergio Lopez Subject: Re: [PATCH 2/2] nbd/server: Use drained block ops to quiesce the server Message-ID: <20210601212907.hc4u4hgjxml5aqjd@redhat.com> References: <20210601055728.90849-1-slp@redhat.com> <20210601055728.90849-3-slp@redhat.com> MIME-Version: 1.0 In-Reply-To: <20210601055728.90849-3-slp@redhat.com> User-Agent: NeoMutt/20210205 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eblake@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=216.205.24.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.371, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org, qemu-devel@nongnu.org, Max Reitz , Nir Soffer Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, Jun 01, 2021 at 07:57:28AM +0200, Sergio Lopez wrote: > Before switching between AioContexts we need to make sure that we're > fully quiesced ("nb_requests == 0" for every client) when entering the > drained section. > > To do this, we set "quiescing = true" for every client on > ".drained_begin" to prevent new coroutines to be created, and check if s/to be created/from being created/ > "nb_requests == 0" on ".drained_poll". Finally, once we're exiting the > drained section, on ".drained_end" we set "quiescing = false" and > call "nbd_client_receive_next_request()" to resume the processing of > new requests. > > With these changes, "blk_aio_attach()" and "blk_aio_detach()" can be > reverted to be as simple as they were before f148ae7d36. Is that reversion planned to be patch 3 of your series in v2? > > RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1960137 > Suggested-by: Kevin Wolf > Signed-off-by: Sergio Lopez > --- > nbd/server.c | 99 +++++++++++++++++++++++++++++++++++++++------------- > 1 file changed, 75 insertions(+), 24 deletions(-) > -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org