Commit ac9fde24 authored Jun 07, 2013 by Qin Chuanyu Committed by Michael S. Tsirkin Sep 17, 2013

vhost: wake up worker outside spin_lock



the wake_up_process func is included by spin_lock/unlock in
vhost_work_queue,
but it could be done outside the spin_lock.
I have test it with kernel 3.0.27 and guest suse11-sp2 using iperf,
the num as below.
                  original                 modified
thread_num  tp(Gbps)   vhost(%)  |  tp(Gbps)     vhost(%)
1           9.59        28.82    |   9.59        27.49
8           9.61        32.92    |   9.62        26.77
64          9.58        46.48    |   9.55        38.99
256         9.6         63.7     |   9.6         52.59

Signed-off-by: Chuanyu Qin <qinchuanyu@huawei.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

parent 272b98c6

drivers/vhost/vhost.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -161,10 +161,12 @@ void vhost_work_queue(struct vhost_dev dev, struct vhost_work work)
		if (list_empty(&work->node)) {
		list_add_tail(&work->node, &dev->work_list);
		work->queue_seq++;
		spin_unlock_irqrestore(&dev->work_lock, flags);
		wake_up_process(dev->worker);
		}
		} else {
		spin_unlock_irqrestore(&dev->work_lock, flags);
		}
		}
		EXPORT_SYMBOL_GPL(vhost_work_queue);

		void vhost_poll_queue(struct vhost_poll *poll)