From nobody Tue Feb 10 09:24:59 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (208.118.235.17 [208.118.235.17]) by mx.zohomail.com with SMTPS id 1539066546656533.5553501580466; Mon, 8 Oct 2018 23:29:06 -0700 (PDT) Received: from localhost ([::1]:49821 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g9lVs-0000oQ-GK for importer@patchew.org; Tue, 09 Oct 2018 02:29:00 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34866) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g9lUc-0000C4-28 for qemu-devel@nongnu.org; Tue, 09 Oct 2018 02:27:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1g9lUb-0006ec-CR for qemu-devel@nongnu.org; Tue, 09 Oct 2018 02:27:42 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53254) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1g9lUb-0006dU-6K for qemu-devel@nongnu.org; Tue, 09 Oct 2018 02:27:41 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1032D5D66B for ; Tue, 9 Oct 2018 06:27:40 +0000 (UTC) Received: from xz-x1.nay.redhat.com (dhcp-14-128.nay.redhat.com [10.66.14.128]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8D5586595C; Tue, 9 Oct 2018 06:27:37 +0000 (UTC) From: Peter Xu To: qemu-devel@nongnu.org Date: Tue, 9 Oct 2018 14:27:14 +0800 Message-Id: <20181009062718.1914-3-peterx@redhat.com> In-Reply-To: <20181009062718.1914-1-peterx@redhat.com> References: <20181009062718.1914-1-peterx@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Tue, 09 Oct 2018 06:27:40 +0000 (UTC) Content-Transfer-Encoding: quoted-printable 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] [PATCH v9 2/6] monitor: resume the monitor earlier if needed 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: "Dr . David Alan Gilbert" , peterx@redhat.com, Markus Armbruster , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RDMRC_1 RSF_0 Z_629925259 SPT_0 Content-Type: text/plain; charset="utf-8" Currently when QMP request queue full we won't resume the monitor until we have completely handled the current command. It's not necessary since even before it's handled the queue is already non-full. Moving the resume logic earlier before the command execution. Note that now monitor_resume() is heavy weighted after 8af6bb14a3a8 and it's even possible (as pointed out by Marc-Andr=C3=A9) that the function itself may try to take the monitor lock again, so let's do the resume after the monitor lock is released to avoid possible dead lock. Signed-off-by: Peter Xu --- monitor.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/monitor.c b/monitor.c index 1f83775fff..f5911399d8 100644 --- a/monitor.c +++ b/monitor.c @@ -4149,6 +4149,12 @@ static void monitor_qmp_bh_dispatcher(void *data) need_resume =3D !qmp_oob_enabled(mon) || mon->qmp.qmp_requests->length =3D=3D QMP_REQ_QUEUE_LEN_MAX - 1; qemu_mutex_unlock(&mon->qmp.qmp_queue_lock); + + if (need_resume) { + /* Pairs with the monitor_suspend() in handle_qmp_command() */ + monitor_resume(mon); + } + if (req_obj->req) { trace_monitor_qmp_cmd_in_band(qobject_get_try_str(req_obj->id) ?: = ""); monitor_qmp_dispatch(mon, req_obj->req, req_obj->id); @@ -4160,10 +4166,6 @@ static void monitor_qmp_bh_dispatcher(void *data) qobject_unref(rsp); } =20 - if (need_resume) { - /* Pairs with the monitor_suspend() in handle_qmp_command() */ - monitor_resume(mon); - } qmp_request_free(req_obj); =20 /* Reschedule instead of looping so the main loop stays responsive */ --=20 2.17.1