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=-8.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 7DD3DC433DB for ; Mon, 1 Feb 2021 15:33:20 +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 16C6064EA2 for ; Mon, 1 Feb 2021 15:33:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 16C6064EA2 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]:37508 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l6bCZ-0002Au-4N for qemu-devel@archiver.kernel.org; Mon, 01 Feb 2021 10:33:19 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:38926) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l6bB5-0000Um-KK for qemu-devel@nongnu.org; Mon, 01 Feb 2021 10:31:47 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:58641) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1l6bB3-0008MS-5v for qemu-devel@nongnu.org; Mon, 01 Feb 2021 10:31:47 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1612193504; 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=ekzvSnkHfS1y8pUviQR0fS+C99lEJ3TR3nap/rSYm+I=; b=GesjYQQ1CEJvw4XfUz3c59Ne88/AHF8/RRDh9gDSPmkbiRiZ5YEt0n6GICvScr+5J5xRTu eQuTX1hjCbIUaNJyAQFmSHB3mNxxuytoYWo5WI/0XKQUgNGK+x1CyNV41hSCIqeiFRstov DCmeYgSvCVIrLufqmS5gYTiLM7AdOto= 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-214-NXRlhxvJMxOH0zGfflrfmg-1; Mon, 01 Feb 2021 10:31:40 -0500 X-MC-Unique: NXRlhxvJMxOH0zGfflrfmg-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 EE087800D53; Mon, 1 Feb 2021 15:31:39 +0000 (UTC) Received: from merkur.fritz.box (ovpn-112-72.ams2.redhat.com [10.36.112.72]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CB9A739A64; Mon, 1 Feb 2021 15:31:35 +0000 (UTC) Date: Mon, 1 Feb 2021 16:31:34 +0100 From: Kevin Wolf To: Sergio Lopez Subject: Re: [PATCH v4 0/2] nbd/server: Quiesce coroutines on context switch Message-ID: <20210201153134.GE13157@merkur.fritz.box> References: <20210201125032.44713-1-slp@redhat.com> MIME-Version: 1.0 In-Reply-To: <20210201125032.44713-1-slp@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=kwolf@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=63.128.21.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.351, 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=unavailable 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: qemu-devel@nongnu.org, qemu-block@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Am 01.02.2021 um 13:50 hat Sergio Lopez geschrieben: > This series allows the NBD server to properly switch between AIO contexts, > having quiesced recv_coroutine and send_coroutine before doing the transition. > > We need this because we send back devices running in IO Thread owned contexts > to the main context when stopping the data plane, something that can happen > multiple times during the lifetime of a VM (usually during the boot sequence or > on a reboot), and we drag the NBD server of the correspoing export with it. > > While there, fix also a problem caused by a cross-dependency between > closing the export's client connections and draining the block > layer. The visible effect of this problem was QEMU getting hung when > the guest request a power off while there's an active NBD client. Reviewed-by: Kevin Wolf