Subject: Re: [PATCH 09/16] virtio-net: drop config_mutex

From: "Michael S. Tsirkin" <[email-masked]>
Date: Mon, 6 Oct 2014 14:56:36 +0300

On Mon, Oct 06, 2014 at 03:46:15PM +0400, Sergei Shtylyov wrote:
> Hello.
> 
> On 10/5/2014 8:07 PM, Michael S. Tsirkin wrote:
> 
> >config_mutex served two purposes: prevent multiple concurrent config
> >change handlers, and synchronize access to config_enable flag.
> 
> >Since commit dbf2576e37da0fcc7aacbfbb9fd5d3de7888a3c1
> >     workqueue: make all workqueues non-reentrant
> >all workqueues are non-reentrant, and config_enable
> >is now gone.
> 
> >Get rid of the unnecessary lock.
> 
> >Signed-off-by: Michael S. Tsirkin <[email-masked]>
> >---
> >  drivers/net/virtio_net.c | 7 +------
> >  1 file changed, 1 insertion(+), 6 deletions(-)
> 
> >diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> >index fa17afa..d80fef4 100644
> >--- a/drivers/net/virtio_net.c
> >+++ b/drivers/net/virtio_net.c
> [...]
> >@@ -1430,7 +1426,7 @@ static void virtnet_config_changed_work(struct work_struct *work)
> >  		netif_tx_stop_all_queues(vi->dev);
> >  	}
> >  done:
> >-	mutex_unlock(&vi->config_lock);
> >+	return;
> 
>    There's no need for this *return*.
>

I know - it's removed by the follow-up patch.
It's formatted like this to make diff smaller
and make review easier.
 
> >  }
> >
> >  static void virtnet_config_changed(struct virtio_device *vdev)
> 
> WBR, Sergei