From patchwork Wed Feb 17 22:14:41 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marcelo Tosatti X-Patchwork-Id: 45773 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [199.232.76.165]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 0DC02B7E39 for ; Fri, 19 Feb 2010 00:58:22 +1100 (EST) Received: from localhost ([127.0.0.1]:35096 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Ni6tX-0005on-O4 for incoming@patchwork.ozlabs.org; Thu, 18 Feb 2010 08:58:19 -0500 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Ni6st-0005nj-6W for qemu-devel@nongnu.org; Thu, 18 Feb 2010 08:57:39 -0500 Received: from [199.232.76.173] (port=50293 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Ni6ss-0005nX-Tg for qemu-devel@nongnu.org; Thu, 18 Feb 2010 08:57:38 -0500 Received: from Debian-exim by monty-python.gnu.org with spam-scanned (Exim 4.60) (envelope-from ) id 1Ni6sr-0001PQ-IN for qemu-devel@nongnu.org; Thu, 18 Feb 2010 08:57:38 -0500 Received: from mx1.redhat.com ([209.132.183.28]:61619) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1Ni6sq-0001P3-Sh for qemu-devel@nongnu.org; Thu, 18 Feb 2010 08:57:37 -0500 Received: from int-mx03.intmail.prod.int.phx2.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.16]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o1IDvZws014402 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 18 Feb 2010 08:57:35 -0500 Received: from ns3.rdu.redhat.com (ns3.rdu.redhat.com [10.11.255.199]) by int-mx03.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o1IDvYwZ024516; Thu, 18 Feb 2010 08:57:34 -0500 Received: from amt.cnet (vpn-8-98.rdu.redhat.com [10.11.8.98]) by ns3.rdu.redhat.com (8.13.8/8.13.8) with ESMTP id o1IDvVw9025566; Thu, 18 Feb 2010 08:57:32 -0500 Received: from amt.cnet (amt.cnet [127.0.0.1]) by amt.cnet (Postfix) with ESMTP id 9322168A872; Thu, 18 Feb 2010 11:57:21 -0200 (BRST) Received: (from marcelo@localhost) by amt.cnet (8.14.3/8.14.3/Submit) id o1IDvJFR007755; Thu, 18 Feb 2010 11:57:19 -0200 Message-Id: <20100217221701.041682707@redhat.com> User-Agent: quilt/0.47-1 Date: Wed, 17 Feb 2010 20:14:41 -0200 From: Marcelo Tosatti To: kvm@vger.kernel.org, qemu-devel@nongnu.org References: <20100217221439.351652889@redhat.com> Content-Disposition: inline; filename=kvm-specific-wait-io-event X-Scanned-By: MIMEDefang 2.67 on 10.5.11.16 X-detected-operating-system: by monty-python.gnu.org: Genre and OS details not recognized. Cc: Marcelo Tosatti , avi@redhat.com Subject: [Qemu-devel] [patch uq/master 2/4] qemu: kvm specific wait_io_event X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org In KVM mode the global mutex is released when vcpus are executing, which means acquiring the fairness mutex is not required. Also for KVM there is one thread per vcpu, so tcg_has_work is meaningless. Add a new qemu_wait_io_event_common function to hold common code between TCG/KVM. Signed-off-by: Marcelo Tosatti Index: qemu/vl.c =================================================================== --- qemu.orig/vl.c +++ qemu/vl.c @@ -3382,6 +3382,7 @@ static QemuCond qemu_pause_cond; static void block_io_signals(void); static void unblock_io_signals(void); static int tcg_has_work(void); +static int cpu_has_work(CPUState *env); static int qemu_init_main_loop(void) { @@ -3402,6 +3403,15 @@ static int qemu_init_main_loop(void) return 0; } +static void qemu_wait_io_event_common(CPUState *env) +{ + if (env->stop) { + env->stop = 0; + env->stopped = 1; + qemu_cond_signal(&qemu_pause_cond); + } +} + static void qemu_wait_io_event(CPUState *env) { while (!tcg_has_work()) @@ -3418,11 +3428,15 @@ static void qemu_wait_io_event(CPUState qemu_mutex_unlock(&qemu_fair_mutex); qemu_mutex_lock(&qemu_global_mutex); - if (env->stop) { - env->stop = 0; - env->stopped = 1; - qemu_cond_signal(&qemu_pause_cond); - } + qemu_wait_io_event_common(env); +} + +static void qemu_kvm_wait_io_event(CPUState *env) +{ + while (!cpu_has_work(env)) + qemu_cond_timedwait(env->halt_cond, &qemu_global_mutex, 1000); + + qemu_wait_io_event_common(env); } static int qemu_cpu_exec(CPUState *env); @@ -3448,7 +3462,7 @@ static void *kvm_cpu_thread_fn(void *arg while (1) { if (cpu_can_run(env)) qemu_cpu_exec(env); - qemu_wait_io_event(env); + qemu_kvm_wait_io_event(env); } return NULL;