From: Jason Wang <jasowang@redhat.com>
To: Amos Kong <akong@redhat.com>
Cc: mst@redhat.com, mashirle@us.ibm.com, krkumar2@in.ibm.com,
habanero@linux.vnet.ibm.com, rusty@rustcorp.com.au,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org, edumazet@google.com,
tahm@linux.vnet.ibm.com, jwhan@filewood.snu.ac.kr,
davem@davemloft.net, kvm@vger.kernel.org, sri@us.ibm.com
Subject: Re: [net-next RFC V5 4/5] virtio_net: multiqueue support
Date: Fri, 06 Jul 2012 15:45:38 +0800 [thread overview]
Message-ID: <4FF697A2.2000502@redhat.com> (raw)
In-Reply-To: <4FF5F2F2.9050307@redhat.com>
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;
> ...
>
next prev parent reply other threads:[~2012-07-06 7:43 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-05 10:29 [net-next RFC V5 0/5] Multiqueue virtio-net Jason Wang
2012-07-05 10:29 ` [net-next RFC V5 1/5] virtio_net: Introduce VIRTIO_NET_F_MULTIQUEUE Jason Wang
2012-07-05 10:29 ` [net-next RFC V5 2/5] virtio_ring: move queue_index to vring_virtqueue Jason Wang
2012-07-05 11:40 ` Sasha Levin
2012-07-06 3:17 ` Jason Wang
2012-07-26 8:20 ` Paolo Bonzini
2012-07-30 3:30 ` Jason Wang
2012-07-05 10:29 ` [net-next RFC V5 3/5] virtio: intorduce an API to set affinity for a virtqueue Jason Wang
2012-07-27 14:38 ` Paolo Bonzini
2012-07-29 20:40 ` Michael S. Tsirkin
2012-07-30 6:27 ` Paolo Bonzini
2012-08-09 15:14 ` Paolo Bonzini
2012-08-09 15:13 ` Paolo Bonzini
2012-08-09 15:35 ` Avi Kivity
2012-07-05 10:29 ` [net-next RFC V5 4/5] virtio_net: multiqueue support Jason Wang
2012-07-05 20:02 ` Amos Kong
2012-07-06 7:45 ` Jason Wang [this message]
2012-07-20 13:40 ` Michael S. Tsirkin
2012-07-21 12:02 ` Sasha Levin
2012-07-23 5:54 ` Jason Wang
2012-07-23 9:28 ` Sasha Levin
2012-07-30 3:29 ` Jason Wang
2012-07-29 9:44 ` Michael S. Tsirkin
2012-07-30 3:26 ` Jason Wang
2012-07-30 13:00 ` Sasha Levin
2012-07-23 5:48 ` Jason Wang
2012-07-29 9:50 ` Michael S. Tsirkin
2012-07-30 5:15 ` Jason Wang
2012-07-05 10:29 ` [net-next RFC V5 5/5] virtio_net: support negotiating the number of queues through ctrl vq Jason Wang
2012-07-05 12:51 ` Sasha Levin
2012-07-05 20:07 ` Amos Kong
2012-07-06 7:46 ` Jason Wang
2012-07-06 3:20 ` Jason Wang
2012-07-06 6:38 ` Stephen Hemminger
2012-07-06 9:26 ` Jason Wang
2012-07-06 8:10 ` Sasha Levin
2012-07-09 20:13 ` Ben Hutchings
2012-07-20 12:33 ` Michael S. Tsirkin
2012-07-23 5:32 ` Jason Wang
2012-07-05 17:45 ` [net-next RFC V5 0/5] Multiqueue virtio-net Rick Jones
2012-07-06 7:42 ` Jason Wang
2012-07-06 16:23 ` Rick Jones
2012-07-09 3:23 ` Jason Wang
2012-07-09 16:46 ` Rick Jones
2012-07-08 8:19 ` Ronen Hod
2012-07-09 5:35 ` Jason Wang
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