From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:57138) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QFlot-0002Wd-Kt for qemu-devel@nongnu.org; Fri, 29 Apr 2011 07:25:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QFlos-00027O-NM for qemu-devel@nongnu.org; Fri, 29 Apr 2011 07:25:11 -0400 Received: from mx1.redhat.com ([209.132.183.28]:65459) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QFlos-00027F-Bh for qemu-devel@nongnu.org; Fri, 29 Apr 2011 07:25:10 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p3TBP9lq032202 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Fri, 29 Apr 2011 07:25:09 -0400 From: Alon Levy Date: Fri, 29 Apr 2011 14:25:06 +0300 Message-Id: <1304076306-15867-1-git-send-email-alevy@redhat.com> Subject: [Qemu-devel] [PATCHv3] virtio-serial-bus: use bh for unthrottling List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: amit.shah@redhat.com Instead of calling flush_queued_data when unthrottling, schedule a bh. That way we can return immediately to the caller, and the flush uses the same call path as a have_data for callbackee. No migration change is required because bh are called from vm_stop. --- hw/virtio-serial-bus.c | 12 ++++++++++-- hw/virtio-serial.h | 5 +++++ 2 files changed, 15 insertions(+), 2 deletions(-) diff --git a/hw/virtio-serial-bus.c b/hw/virtio-serial-bus.c index f10d48f..ca0581b 100644 --- a/hw/virtio-serial-bus.c +++ b/hw/virtio-serial-bus.c @@ -285,6 +285,13 @@ size_t virtio_serial_guest_ready(VirtIOSerialPort *port) return 0; } +static void flush_queued_data_bh(void *opaque) +{ + VirtIOSerialPort *port = opaque; + + flush_queued_data(port); +} + void virtio_serial_throttle_port(VirtIOSerialPort *port, bool throttle) { if (!port) { @@ -295,8 +302,7 @@ void virtio_serial_throttle_port(VirtIOSerialPort *port, bool throttle) if (throttle) { return; } - - flush_queued_data(port); + qemu_bh_schedule(port->bh); } /* Guest wants to notify us of some event */ @@ -726,6 +732,7 @@ static int virtser_port_qdev_init(DeviceState *qdev, DeviceInfo *base) bool plugging_port0; port->vser = bus->vser; + port->bh = qemu_bh_new(flush_queued_data_bh, port); /* * Is the first console port we're seeing? If so, put it up at @@ -792,6 +799,7 @@ static int virtser_port_qdev_exit(DeviceState *qdev) VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, qdev); VirtIOSerial *vser = port->vser; + qemu_bh_delete(port->bh); remove_port(port->vser, port->id); QTAILQ_REMOVE(&vser->ports, port, next); diff --git a/hw/virtio-serial.h b/hw/virtio-serial.h index 5eb948e..0fa03d1 100644 --- a/hw/virtio-serial.h +++ b/hw/virtio-serial.h @@ -119,6 +119,11 @@ struct VirtIOSerialPort { uint32_t iov_idx; uint64_t iov_offset; + /* + * When unthrottling we use a buttomhalf to call flush_queued_data. + */ + QEMUBH *bh; + /* Identify if this is a port that binds with hvc in the guest */ uint8_t is_console; -- 1.7.5