From mboxrd@z Thu Jan 1 00:00:00 1970 From: Qin Chuanyu Subject: [PATCH] vhost: wake up worker outside spin_lock Date: Fri, 7 Jun 2013 21:50:16 +0800 Message-ID: <51B1E518.1070003@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Cc: , To: , Return-path: Sender: netdev-owner@vger.kernel.org List-Id: kvm.vger.kernel.org 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 --- drivers/vhost/vhost.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 94dbd25..dcc7a17 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -146,9 +146,11 @@ static inline void vhost_work_queue(struct vhost_dev *dev, 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); } void vhost_poll_queue(struct vhost_poll *poll) -- 1.7.3.1.msysgit.0