From patchwork Fri Jul 19 13:43:44 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 11050177 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 571B41800 for ; Fri, 19 Jul 2019 13:47:13 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 455D21FF0B for ; Fri, 19 Jul 2019 13:47:13 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 39AFA1FFCD; Fri, 19 Jul 2019 13:47:13 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id E0BE51FF0B for ; Fri, 19 Jul 2019 13:47:12 +0000 (UTC) Received: from localhost ([::1]:45694 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hoTE6-0006tf-Rm for patchwork-qemu-devel@patchwork.kernel.org; Fri, 19 Jul 2019 09:47:10 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:40523) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hoTBI-00048c-Lh for qemu-devel@nongnu.org; Fri, 19 Jul 2019 09:44:17 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hoTBH-0003dL-LT for qemu-devel@nongnu.org; Fri, 19 Jul 2019 09:44:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50746) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hoTBF-0003a2-DC; Fri, 19 Jul 2019 09:44:13 -0400 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 mx1.redhat.com (Postfix) with ESMTPS id 9B51BC0703A8; Fri, 19 Jul 2019 13:44:11 +0000 (UTC) Received: from dhcp-200-226.str.redhat.com (dhcp-200-226.str.redhat.com [10.33.200.226]) by smtp.corp.redhat.com (Postfix) with ESMTP id AFD29608A4; Fri, 19 Jul 2019 13:44:10 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Date: Fri, 19 Jul 2019 15:43:44 +0200 Message-Id: <20190719134345.23526-13-kwolf@redhat.com> In-Reply-To: <20190719134345.23526-1-kwolf@redhat.com> References: <20190719134345.23526-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Fri, 19 Jul 2019 13:44:11 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 12/13] vl: Drain before (block) job cancel when quitting 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: kwolf@redhat.com, peter.maydell@linaro.org, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Max Reitz If the main loop cancels all block jobs while the block layer is not drained, this cancelling may not happen instantaneously. We can start a drained section before vm_shutdown(), which entails another bdrv_drain_all(); this nested bdrv_drain_all() will thus be a no-op, basically. We do not have to end the drained section, because we actually do not want any requests to happen from this point on. Signed-off-by: Max Reitz Signed-off-by: Kevin Wolf --- vl.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/vl.c b/vl.c index a5808f9a02..53335a5470 100644 --- a/vl.c +++ b/vl.c @@ -4480,6 +4480,17 @@ int main(int argc, char **argv, char **envp) */ migration_shutdown(); + /* + * We must cancel all block jobs while the block layer is drained, + * or cancelling will be affected by throttling and thus may block + * for an extended period of time. + * vm_shutdown() will bdrv_drain_all(), so we may as well include + * it in the drained section. + * We do not need to end this section, because we do not want any + * requests happening from here on anyway. + */ + bdrv_drain_all_begin(); + /* No more vcpu or device emulation activity beyond this point */ vm_shutdown();