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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 2816BC433F5 for ; Mon, 14 Mar 2022 15:49:12 +0000 (UTC) Received: from localhost ([::1]:48206 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nTmwZ-0002M3-2d for qemu-devel@archiver.kernel.org; Mon, 14 Mar 2022 11:49:11 -0400 Received: from eggs.gnu.org ([209.51.188.92]:44144) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nTmtd-0006ME-7w for qemu-devel@nongnu.org; Mon, 14 Mar 2022 11:46:09 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:48416) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nTmtW-0007Za-Ow for qemu-devel@nongnu.org; Mon, 14 Mar 2022 11:46:08 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1647272762; 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=CBomr4i2qdHcD4X+hkpYtDkRqwcFbzvQ4GFbtECpjUM=; b=IjdUItVeDrPvK24BhXqfa6+vGxvev1IAxoAxs4LdZp0A0mlOUGjk+E0TaVlVd9jxMuJQwY ZseT3E3/7i3Q2H9cco+qSWy3UBESng4edHNhH6XQGZrTw3CSIX1pp/jZAJUqxHEnxcCZat GFMGw7/Yv/mWci6+VwjKNoLsCHkCvr4= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-427-tznzmJ60MmSyUvL6QliX-Q-1; Mon, 14 Mar 2022 11:45:58 -0400 X-MC-Unique: tznzmJ60MmSyUvL6QliX-Q-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 3FB63802A6A; Mon, 14 Mar 2022 15:45:58 +0000 (UTC) Received: from redhat.com (unknown [10.22.17.185]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9D8B441136EE; Mon, 14 Mar 2022 15:45:56 +0000 (UTC) Date: Mon, 14 Mar 2022 10:45:55 -0500 From: Eric Blake To: Vladimir Sementsov-Ogievskiy Subject: Re: [PATCH v2] block/nbd.c: Fixed IO request coroutine not being wakeup when kill NBD server Message-ID: <20220314154555.vu4ix45c4c4bvffy@redhat.com> References: <20220309074844.275450-1-lei.rao@intel.com> MIME-Version: 1.0 In-Reply-To: User-Agent: NeoMutt/20211029-410-d8ee8c X-Scanned-By: MIMEDefang 2.84 on 10.11.54.1 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=170.10.129.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, qemu-block@nongnu.org, Rao Lei , qemu-devel@nongnu.org, chen.zhang@intel.com, hreitz@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, Mar 09, 2022 at 04:21:01PM +0300, Vladimir Sementsov-Ogievskiy wrote: > 09.03.2022 10:48, Rao Lei wrote: > > During the IO stress test, the IO request coroutine has a probability that is > > can't be awakened when the NBD server is killed. > > > > The GDB stack is as follows: > > When we do failover in COLO mode, QEMU will hang while it is waiting for > > the in-flight IO. From the call trace, we can see the IO request coroutine > > has yielded in nbd_co_send_request(). When we kill the NBD server, it will never > > be wake up. Actually, when we do IO stress test, it will have a lot of > > requests in free_sema queue. When the NBD server is killed, current > > MAX_NBD_REQUESTS finishes with errors but they wake up at most > > MAX_NBD_REQEUSTS from the queue. So, let's move qemu_co_queue_next out > > to fix this issue. > > > > Signed-off-by: Lei Rao > > Reviewed-by: Vladimir Sementsov-Ogievskiy Thanks; will queue through my NBD tree. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org