On Mon, 2013-04-08 at 10:10 +0300, Michael S. Tsirkin wrote: > On Wed, Apr 03, 2013 at 02:17:37PM +0800, Asias He wrote: > > Currently, vs->vs_endpoint is used indicate if the endpoint is setup or > > not. It is set or cleared in vhost_scsi_set_endpoint() or > > vhost_scsi_clear_endpoint() under the vs->dev.mutex lock. However, when > > we check it in vhost_scsi_handle_vq(), we ignored the lock. > > > > Instead of using the vs->vs_endpoint and the vs->dev.mutex lock to > > indicate the status of the endpoint, we use per virtqueue > > vq->private_data to indicate it. In this way, we can only take the > > vq->mutex lock which is per queue and make the concurrent multiqueue > > process having less lock contention. Further, in the read side of > > vq->private_data, we can even do not take the lock if it is accessed in > > the vhost worker thread, because it is protected by "vhost rcu". > > > > Signed-off-by: Asias He <asias@xxxxxxxxxx> > > Not strictly 3.9 material itself but needed for the next one. > > Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx> > Applied to target-pending/master with a small change to s/VHOST_FEATURES/VHOST_SCSI_FEATURES Thanks Asias and MST! --nab -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
