From patchwork Tue Sep 25 08:15:07 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wolfgang Bumiller X-Patchwork-Id: 10613609 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 62AC2161F for ; Tue, 25 Sep 2018 08:16:35 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 582AC29AFF for ; Tue, 25 Sep 2018 08:16:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4CBC329B1D; Tue, 25 Sep 2018 08:16:35 +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=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id D1B1429B01 for ; Tue, 25 Sep 2018 08:16:34 +0000 (UTC) Received: from localhost ([::1]:51583 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g4iWH-0006GI-Nd for patchwork-qemu-devel@patchwork.kernel.org; Tue, 25 Sep 2018 04:16:33 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37463) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g4iV6-0005DW-H8 for qemu-devel@nongnu.org; Tue, 25 Sep 2018 04:15:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1g4iV4-00080x-6P for qemu-devel@nongnu.org; Tue, 25 Sep 2018 04:15:20 -0400 Received: from proxmox-new.maurer-it.com ([212.186.127.180]:29873) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1g4iV3-0007sd-Oq for qemu-devel@nongnu.org; Tue, 25 Sep 2018 04:15:18 -0400 Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id EA1B44234B; Tue, 25 Sep 2018 10:15:08 +0200 (CEST) From: Wolfgang Bumiller To: qemu-devel@nongnu.org Date: Tue, 25 Sep 2018 10:15:07 +0200 Message-Id: <20180925081507.11873-3-w.bumiller@proxmox.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20180925081507.11873-1-w.bumiller@proxmox.com> References: <20180925081507.11873-1-w.bumiller@proxmox.com> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 212.186.127.180 Subject: [Qemu-devel] [PATCH rebased 2/2] monitor: delay monitor iothread creation X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Markus Armbruster , Peter Xu , "Dr. David Alan Gilbert" Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP Commit d32749deb615 moved the call to monitor_init_globals() to before os_daemonize(), making it an unsuitable place to spawn the monitor iothread as it won't be inherited over the fork() in os_daemonize(). We now spawn the thread the first time we instantiate a monitor which actually has use_io_thread == true. Instantiation of monitors happens only after os_daemonize(). We still need to create the qmp_dispatcher_bh when not using iothreads, so this now still happens in monitor_init_globals(). Signed-off-by: Wolfgang Bumiller Fixes: d32749deb615 ("monitor: move init global earlier") Reviewed-by: Peter Xu Tested-by: Peter Xu --- Resolved conflict from the removal of qmp_respond_bh. No functional changes otherwise. monitor.c | 35 +++++++++++++++++++++-------------- 1 file changed, 21 insertions(+), 14 deletions(-) diff --git a/monitor.c b/monitor.c index e5462567e4..53dc1dddc6 100644 --- a/monitor.c +++ b/monitor.c @@ -707,9 +707,14 @@ static void monitor_qapi_event_init(void) static void handle_hmp_command(Monitor *mon, const char *cmdline); +static void monitor_iothread_init(void); + static void monitor_data_init(Monitor *mon, bool skip_flush, bool use_io_thread) { + if (use_io_thread && !mon_iothread) { + monitor_iothread_init(); + } memset(mon, 0, sizeof(Monitor)); qemu_mutex_init(&mon->mon_lock); qemu_mutex_init(&mon->qmp.qmp_queue_lock); @@ -4447,15 +4452,6 @@ static AioContext *monitor_get_aio_context(void) static void monitor_iothread_init(void) { mon_iothread = iothread_create("mon_iothread", &error_abort); - - /* - * The dispatcher BH must run in the main loop thread, since we - * have commands assuming that context. It would be nice to get - * rid of those assumptions. - */ - qmp_dispatcher_bh = aio_bh_new(iohandler_get_aio_context(), - monitor_qmp_bh_dispatcher, - NULL); } void monitor_init_globals(void) @@ -4465,7 +4461,15 @@ void monitor_init_globals(void) sortcmdlist(); qemu_mutex_init(&monitor_lock); qemu_mutex_init(&mon_fdsets_lock); - monitor_iothread_init(); + + /* + * The dispatcher BH must run in the main loop thread, since we + * have commands assuming that context. It would be nice to get + * rid of those assumptions. + */ + qmp_dispatcher_bh = aio_bh_new(iohandler_get_aio_context(), + monitor_qmp_bh_dispatcher, + NULL); } /* These functions just adapt the readline interface in a typesafe way. We @@ -4600,7 +4604,9 @@ void monitor_cleanup(void) * we need to unregister from chardev below in * monitor_data_destroy(), and chardev is not thread-safe yet */ - iothread_stop(mon_iothread); + if (mon_iothread) { + iothread_stop(mon_iothread); + } /* Flush output buffers and destroy monitors */ qemu_mutex_lock(&monitor_lock); @@ -4615,9 +4621,10 @@ void monitor_cleanup(void) /* QEMUBHs needs to be deleted before destroying the I/O thread */ qemu_bh_delete(qmp_dispatcher_bh); qmp_dispatcher_bh = NULL; - - iothread_destroy(mon_iothread); - mon_iothread = NULL; + if (mon_iothread) { + iothread_destroy(mon_iothread); + mon_iothread = NULL; + } } QemuOptsList qemu_mon_opts = {