Re: [PATCH] vhost: Fix retrieval of numa information in PMD

["Tan, Jianfeng" <jianfeng.tan@intel.com>]

On 4/6/2016 2:17 PM, Yuanhan Liu wrote:
> On Wed, Apr 06, 2016 at 02:05:51PM +0800, Tan, Jianfeng wrote:
>>
>> On 4/6/2016 1:44 PM, Yuanhan Liu wrote:
>>> On Wed, Apr 06, 2016 at 01:32:12PM +0800, Tan, Jianfeng wrote:
>>>> Hi,
>>>>
>>>> Just out of interest, seems that the message handling thread which runs
>>>> new_device() is pthread_create() from the thread which calls the
>>>> dev_start(), usually master thread, right? But it's not necessary to be the
>>>> master thread to poll pkts from this vhost port, right? So what's the
>>>> significance to record the numa_node information of message handling thread
>>>> here? Shall we make the decision of numa_realloc based on the final PMD
>>>> thread who is responsible for polling this vhost port?
>>> It doesn't matter on which core we made the decision: the result
>>> would be same since we are querying the numa node info of the
>>> virtio_net dev struct.
>> OK, according to your hint, read numa_realloc() again, it's to keep *dev
>> (struct virtio_net), *dev->virtqueue[], on the same numa socket of shared
>> memory with virtio?
> Sort of, and I'm guessing that the comment have already made it clear?
>
>      /*
>       * Reallocate virtio_dev and vhost_virtqueue data structure to make them on the
>       * same numa node as the memory of vring descriptor.
>       */
>
>> And numa_realloc() is called in vhost_set_vring_addr(), which is after
>> new_device()?
> It's actually before new_device().
>
> 	--yliu

Yes, exactly as you said. Thanks for explanation!

Jianfeng