lkml.org 
[lkml]   [2012]   [Jul]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [net-next RFC V5 4/5] virtio_net: multiqueue support
On 07/06/2012 04:02 AM, Amos Kong wrote:
> On 07/05/2012 06:29 PM, Jason Wang wrote:
>> This patch converts virtio_net to a multi queue device. After negotiated
>> VIRTIO_NET_F_MULTIQUEUE feature, the virtio device has many tx/rx queue pairs,
>> and driver could read the number from config space.
>>
>> The driver expects the number of rx/tx queue paris is equal to the number of
>> vcpus. To maximize the performance under this per-cpu rx/tx queue pairs, some
>> optimization were introduced:
>>
>> - Txq selection is based on the processor id in order to avoid contending a lock
>> whose owner may exits to host.
>> - Since the txq/txq were per-cpu, affinity hint were set to the cpu that owns
>> the queue pairs.
>>
>> Signed-off-by: Krishna Kumar<krkumar2@in.ibm.com>
>> Signed-off-by: Jason Wang<jasowang@redhat.com>
>> ---
> ...
>
>>
>> static int virtnet_probe(struct virtio_device *vdev)
>> {
>> - int err;
>> + int i, err;
>> struct net_device *dev;
>> struct virtnet_info *vi;
>> + u16 num_queues, num_queue_pairs;
>> +
>> + /* Find if host supports multiqueue virtio_net device */
>> + err = virtio_config_val(vdev, VIRTIO_NET_F_MULTIQUEUE,
>> + offsetof(struct virtio_net_config,
>> + num_queues),&num_queues);
>> +
>> + /* We need atleast 2 queue's */
>
> s/atleast/at least/
>
>
>> + if (err || num_queues< 2)
>> + num_queues = 2;
>> + if (num_queues> MAX_QUEUES * 2)
>> + num_queues = MAX_QUEUES;
> num_queues = MAX_QUEUES * 2;
>
> MAX_QUEUES is the limitation of RX or TX.

Right, it's a typo, thanks.
>> +
>> + num_queue_pairs = num_queues / 2;
> ...
>



\
 
 \ /
  Last update: 2012-07-06 10:21    [W:0.151 / U:0.636 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site