Re: [Xen-devel] [PATCH RFC 4/4] xen-netfront: Add support for multiple queues

[Wei Liu <wei.liu2@xxxxxxxxxx>]

On Wed, Jan 15, 2014 at 04:23:24PM +0000, Andrew J. Bennieston wrote:
[...]
> +/* Module parameters */
> +unsigned int xennet_max_queues = 16;
> +module_param(xennet_max_queues, uint, 0644);
> +

This looks quite arbitrary as well.

>  static const struct ethtool_ops xennet_ethtool_ops;
>  
[...]
> +static int write_queue_xenstore_keys(struct netfront_queue *queue,
> +                        struct xenbus_transaction *xbt, int 
> write_hierarchical)
> +{
> +     /* Write the queue-specific keys into XenStore in the traditional
> +      * way for a single queue, or in a queue subkeys for multiple
> +      * queues.
> +      */
> +     struct xenbus_device *dev = queue->info->xbdev;
> +     int err;
> +     const char *message;
> +     char *path;
> +     size_t pathsize;
> +
> +     /* Choose the correct place to write the keys */
> +     if (write_hierarchical) {
> +             pathsize = strlen(dev->nodename) + 10;
> +             path = kzalloc(pathsize, GFP_KERNEL);
> +             if (!path) {
> +                     err = -ENOMEM;
> +                     message = "writing ring references";

This error message doesn't sound right.

> +                     goto error;
> +             }
> +             snprintf(path, pathsize, "%s/queue-%u",
> +                             dev->nodename, queue->number);
> +     }
> +     else
> +             path = (char *)dev->nodename;

Coding style. Should be surounded by {};

> +
[...]
> @@ -1740,10 +1838,17 @@ static int talk_to_netback(struct xenbus_device *dev,
>       int err;
>       unsigned int feature_split_evtchn;
>       unsigned int i = 0;
> +     unsigned int max_queues = 0;
>       struct netfront_queue *queue = NULL;
>  
>       info->netdev->irq = 0;
>  
> +     /* Check if backend supports multiple queues */
> +     err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
> +                     "multi-queue-max-queues", "%u", &max_queues);
> +     if (err < 0)
> +             max_queues = 1;
> +

Need to check if backend provide too big a number for frontend.

Wei.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel