From ac9fde2474d04bd6574a037482e3de02b488a6c6 Mon Sep 17 00:00:00 2001 From: Qin Chuanyu Date: Fri, 7 Jun 2013 21:50:16 +0800 Subject: [PATCH] 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 Signed-off-by: Michael S. Tsirkin --- drivers/vhost/vhost.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 9a9502a4aa50..69068e0d8f31 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -161,9 +161,11 @@ 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); } - spin_unlock_irqrestore(&dev->work_lock, flags); } EXPORT_SYMBOL_GPL(vhost_work_queue); -- GitLab